# Bus Testing: Establishment of Performance Standards, a Bus Model Scoring System, a Pass/Fail Standard and other Program Updates

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2015-14176

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** June 23, 2015
- **Citation:** 80 FR 36112

## Text

DEPARTMENT OF TRANSPORTATION
Federal Transit Administration
49 CFR Part 665
[Docket No. FTA-2015-0019]
RIN 2132-AB11
Bus Testing: Establishment of Performance Standards, a Bus Model Scoring System, a Pass/Fail Standard and other Program Updates

AGENCY:

Federal Transit Administration (FTA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Transit Administration (FTA) proposes to establish a new pass/fail standard and new aggregated scoring system for buses and modified vans (hereafter referred to as “bus” or “buses”) that are subject to FTA's bus testing program, as mandated by Section 20014 of the Moving Ahead for Progress in the 21st Century Act (MAP-21). The proposed pass/fail standard and scoring system address the following categories as required by MAP-21: structural integrity, safety, maintainability, reliability, fuel economy, emissions, noise, and performance. Once FTA issues a rule in final form, recipients will be prohibited from using FTA financial assistance to procure new buses that have not passed the test. FTA is also seeking comment on establishing testing requirements and a scoring system for remanufactured vehicles sold by third-party vendors and procured using FTA funding, which FTA plans to address in a subsequent rulemaking action. Finally, FTA is proposing to apply Buy America U.S. content requirements to buses submitted for testing.

DATES:

Comments on this proposed rule must be received on or before August 24, 2015.

ADDRESSES:

Please submit your comments (identified by the agency name and DOT Docket ID Number FTA-2015-0019 or RIN 2132-AB11) by only one of the following methods:

Electronic:
Go to the Federal eRulemaking Portal at
www.regulations.gov
and follow the online instructions for submitting comments.

Mail:
Docket Management Facility: U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

Hand Delivery or Courier:
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., between 9 a.m. and 5 p.m. ET, Monday through Friday, except Federal holidays.

Fax:
202-493-2251.

Additional instructions:
You must include the agency name (Federal Transit Administration) and Docket number (FTA-2015-0019) for this notice at the beginning of your comments. If you wish to receive confirmation that FTA received your submission, please include a self-addressed stamped postcard. Note that all comments received will be posted without change to
http://www.regulations.gov.
Note that any personal information provided will be available to internet users.

Privacy Act:
You may review DOT's complete Privacy Act Statement in the
Federal Register
published on April 11, 2000 (65 FR 19477) or you may visit
http://docketsinfo.dot.gov.

Docket Access:
For internet access to the docket to read background documents and comments received, go to
http://www.regulations.gov.
Background documents and comments received may also be viewed at the U.S. Department of Transportation Docket Operations, 1200 New Jersey Ave. SE., West Building Ground Floor, Room W12-140, Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT:

For technical information, Gregory Rymarz, Bus Testing Program Manager, Office of Research, Demonstration and Innovation (TRI), (202) 366-6410,
gregory.rymarz@dot.gov.
For legal information, Richard Wong, Office of the Chief Counsel (TCC), (202) 366-0675,
richard.wong@dot.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

A. Executive Summary

B. Background

C. Performance Standards By Test Category

1. Structural Integrity

2. Safety

3. Maintainability

4. Reliability

5. Fuel Economy

6. Emissions

7. Noise

8. Performance

D. Bus Model Scoring System

1. Determination of Scores by Test Category

2. Calculation of The Aggregate Score

E. Pass/Fail Standard

1. Effective Date of Pass/Fail Requirements

2. Resolving The Failure To Meet A Performance Standard

3. Scoring of New Partial Tests

4. Scoring of Existing Bus Models

5. Re-Testing of Existing Bus Models To Raise the Aggregate Score

F. Other Proposed Program Changes

1. Bus Payloading Procedures

2. Elimination of On-Road Fuel Economy Testing

3. Bus Passenger Load for Emissions Testing

4. Bus Testing Entrance Requirements

5. Scheduling of Testing

6. Test Requirements Review Milestone

7. Penalty for Unauthorized Maintenance and Modification

8. Testing of Remanufactured Buses

G. Section by Section Analysis

H. Regulatory Analyses and Notices

I. Proposed Rule Text

A. Executive Summary

Purpose

The purpose of this NPRM is to propose minimum performance standards, a scoring system, and a pass/fail threshold for new model transit buses procured with Federal Transit Administration (FTA) financial assistance authorized under 49 U.S.C. Chapter 53. Once FTA issues a rule in final form, FTA recipients will be prohibited from using FTA financial assistance to procure new buses that have not passed the test standard. The proposed standards and scoring system address the following categories: structural integrity, safety, maintainability, reliability, fuel economy, emissions, noise, and performance. The NPRM proposes that buses will need to pass a minimum performance standard in each of these categories in order to receive an overall passing score and be eligible for purchase using FTA financial assistance. The NPRM proposes that buses can achieve higher scores with higher performance in each category. The NPRM proposes a numerical scoring system based on a 100-point scale so that buyers can more effectively compare vehicles.

The NPRM proposes to adopt many of the existing testing procedures and standards used under the current bus testing program. However, the NPRM proposes some changes including: (1) new inspections at bus check-in to verify the bus configuration is within its weight capacity rating at its rated passenger load and an inspection to determine if the major components of the test bus match those identified in the Buy America pre-audit report; (2) elimination of the on-road fuel economy testing and substitute the fuel economy results obtained during the emissions test; and (3) revision to the payloading procedure to recognize the manufacturer's “standee” passenger rating. The proposed rule does not add any new tests to the existing bus testing program—in fact, the NPRM proposes to eliminate one test, the on-road fuel economy test, as equivalent data could

be derived from the more accurate dynamometer testing.

Because FTA provides financial assistance to State and local agencies operating public transportation systems, covering eighty percent (80%) of a vehicle's capital cost, while the State or local government provides a twenty percent (20%) matching share, there is a strong incentive by FTA and local agencies to ensure that those funds are used effectively and efficiently. As part of its stewardship of those funds, Congress directed FTA in 1987 to establish a bus testing program whereby new model buses would first be tested to ensure their ability to withstand the rigors of regular transit service before FTA funds would be spent on those vehicles. In the following years, FTA accumulated comprehensive test data on the scores of buses that had undergone testing, but the program did not assign a comparative ranking to the vehicles. Further, because the program was intended to provide information on a vehicle's performance and Congress did not authorize FTA to use the test data to disqualify a vehicle from participating in FTA-assisted procurements, FTA did not establish a pass/fail performance baseline. Since that time, several tested buses did not meet their expected service lives at the cost of millions of dollars to transit agencies and significant inconvenience to transit riders. In MAP-21, Congress directed FTA to establish a new pass/fail standard for tested buses, including a weighted scoring system that would assist transit bus buyers in selecting an appropriate vehicle. The proposed rule would establish a new scoring system and a pass/fail standard for buses tested under FTA's existing bus testing program, as well as make other administrative changes.

Legal Authority

Section 20014 of the Moving Ahead for Progress in the 21st Century Act (MAP-21) (Pub. L. 121-141), maintained the existing test categories of maintainability, reliability, safety, performance, structural integrity, fuel economy, emissions, and noise in 49 U.S.C. 5318(a). Section 20014 also expanded 49 U.S.C. 5318(e) by adding three new requirements on the use of Chapter 53 funding to acquire new bus models. The first is that new bus models meet performance standards for maintainability, reliability, performance (including braking performance), structural integrity, fuel economy, emissions, and noise. The second is that new bus models acquired with Chapter 53 funds meet the minimum safety performance standards established pursuant to paragraph 5329(b) Public Transportation Safety Program. The third is that the new bus model satisfies an overall pass/fail standard based on the weighted aggregate score derived from each of the existing test categories (maintainability, reliability, safety, performance (including braking performance), structural integrity, fuel economy, emissions, and noise).).

This notice does not address the establishment of the minimum safety performance standards for public transportation vehicles required under 49 U.S.C. 5329(b)(2)(C), which will be addressed in a subsequent rulemaking.

Summary of Key Provisions

The NPRM proposes to take the following actions, the first of which is required by MAP-21 as part of the new “pass/fail” requirement and the remainder of which are discretionary actions proposed by FTA to strengthen the program:

• Codify existing testing procedures and establish a minimum performance standards and a pass/fail scoring system for new bus models, with a minimum passing score of 60 points. A bus model could receive up to an additional 40 points based on its performance above the proposed minimum performance standard in particular test categories. Buses would need to achieve at least a minimum score in each category in order to pass the overall test and be eligible for procurement using FTA financial assistances.

• Establish check-in procedures, including FTA approval, for new bus models proposed for testing.

• Require transit vehicle manufacturers to submit Disadvantaged Business Enterprise (DBE) goals to FTA.

• Determine a new bus model's total passenger load based on the manufacturer's maximum passenger rating, including accommodations for standees.

• Establish a simulated passenger weight of 150 lbs. for seated and standing (standee) passengers, and a weight of 600 lbs. for passengers who use wheelchairs.

• Require test model buses to contain at least 60% domestic components, by cost, consistent with FTA Buy America domestic content requirements.

• The replacement of the on-road fuel economy test with the fuel economy testing already conducted during the emissions test on the chassis dynamometer.

The NPRM also seeks comments on establishing testing procedures, performance standards, and a scoring system for remanufactured vehicles sold by third-party vendors and procured using FTA assistance, which FTA plans to address in a subsequent rulemaking action.

Summary of Benefits and Costs

Table 1 below summarizes the potential benefits and costs of this proposed rule over 10 years and using a 3 and 7 percent discount rate that we were able to quantify. Quantified costs stem from shipping buses to the testing facility, manufacturer testing fees, having repair personnel for bus manufacturers available at the testing site, new paperwork requirements, and increases to the resources needed to operate the Bus Testing Program (which represents most of the quantified costs). Unquantified costs include remedial actions to buses that do not pass the proposed test (which may extend to all the buses in a model represented by the tested bus) and potential improvements to buses to obtain a higher testing score. However, given that 41 of 49 buses tested between January 2010 and February 2013 would have satisfied the proposed performance standards without any design changes, FTA believes that the proposed requirements would not drive systemic changes to all transit bus models. Quantified benefits are from a reduction in unscheduled maintenance costs.

TABLE 1—Discounted Cash Flow Analysis and Net Present Values

Year
Costs
Benefits

Net Cash
Flow

Discount
Rate

DCF @ 3%

Discount
Rate

DCF @ 7%

1
109,171
531,990
422,819
0.03
410,504
0.07
395,158

2
109,171
531,990
422,819
0.03
398,547
0.07
369,306

3
109,171
531,990
422,819
0.03
386,939
0.07
345,146

4
109,171
531,990
422,819
0.03
375,669
0.07
322,567

5
109,171
531,990
422,819
0.03
364,727
0.07
301,464

6
109,171
531,990
422,819
0.03
354,104
0.07
281,742

7
109,171
531,990
422,819
0.03
343,791
0.07
263,310

8
109,171
531,990
422,819
0.03
333,777
0.07
246,085

9
109,171
531,990
422,819
0.03
324,056
0.07
229,986

10
109,171
531,990
422,819
0.03
314,617
0.07
214,940

NPV
3,606,732
NPV
2,969,704

B. Background

FTA's grant programs, including those at 49 U.S.C. 5307, 5310, 5311 and 5339, assist transit agencies with procuring buses. The Federal transit program allows FTA to provide 80% funding for each bus. In 2013, for example FTA funds assisted in the procurement of 8934 new vehicles, of which approximately 5600 buses and modified vans were covered under the existing testing program. Historically, Section 317 of the Surface Transportation and Uniform Relocation Assistance Act of 1987 (STURAA, Pub. Law 100-17) provided that no funds appropriated or made available under the Urban Mass Transportation Act of 1964, as amended, were to be obligated or expended for the acquisition of a new model bus after September 30, 1989, unless a bus of such model had been tested to ensure that the vehicle “will be able to withstand the rigors of transit service” (H. Rept. 100-27, p. 230). In subsection 317(b), Congress mandated seven specific test categories—maintainability, reliability, safety, performance, structural integrity, fuel economy, and noise—augmenting those tests with the addition of braking performance and emissions testing through section 6021 of the Intermodal Surface Transportation Efficiency Act of 1991 (Pub. L. 102-240). These requirements were subsequently codified at 49 U.S.C. 5318.

FTA issued its initial NPRM in May 1989 (54 FR 22716, May 25, 1989) and an interim Final Rule three months later (54 FR 35158, August 23, 1989), establishing a bus testing program that submitted vehicles to seven statutorily-mandated tests resulting in a test report and requiring transit bus manufacturers to submit that completed test report to transit agencies before FTA funds could be expended to purchase those vehicles. Although Congress did not authorize FTA to withhold financial assistance for a vehicle based on the data contained in a test report, FTA expected that the test report would provide accurate and reliable bus performance information to transit authorities that could be used in their purchasing and operational decisions.

Buses procured with FTA assistance are assigned a service life requirement that the recipient must keep the bus in active service for the specified period of time or mileage, whichever occurs first. FTA has five service life categories defined in the current Bus Testing Rule and in our capital program guidance publications:

(1) Large-size, heavy-duty transit buses (approximately 35′-40′ in length, as well as articulated buses) with a minimum service life of 12 years or 500,000 miles;

(2) Medium-size, heavy-duty transit buses (approximately 30′ in length) with a minimum service life of ten years or 350,000 miles;

(3) Medium-size, medium duty transit buses (approximately 30′ in length) with a minimum service life of seven years or 200,000 miles;

(4) Medium-size, light duty transit buses (approximately 25′-35′ in length) with a minimum service life of five years or 150,000 miles; and

(5) Other light duty vehicles such as small buses and regular and specialized vans with a minimum service life of four years or 100,000 miles.

This system successfully remained in place for over twenty years. During the intervening period, however, a handful of bus models that had documented problems in their test reports were able to enter transit service, most notably, a fleet of 226 articulated buses that one of the Nation's largest transit agencies ordered in 2001. After paying $87.7M of the $102.1M contract, the transit agency stopped payments in 2005 due to unresolved problems concerning the suspension systems and structural cracks around the articulation joint, near the axles, and in the rear door header, triggering years of litigation. In addition, in 2009, the transit agency abruptly pulled all of these models from service for safety concerns following a structural failure related to the articulation joint, resulting in lengthier and more crowded commutes for thousands of transit riders. In May 2012, a local court ruled that the transit agency could sell the buses for scrap metal, a move that generated only $1.2M for vehicles that had served barely half of their FTA-funded service lives.

The 2012 Moving Ahead for Progress in the 21st Century Act (MAP-21) amended section 5318 by adding new requirements to subsection 5318(e),
Acquiring New Bus Models,
including a bus model scoring system and a pass/fail standard based on the weighted aggregate score for each of the existing performance standards (maintainability, reliability, performance (including braking performance), structural integrity, fuel economy, emissions, and noise).

MAP-21 also amended 5318(e) to require that new bus models meet the minimum safety performance standards to be established by the Secretary of Transportation pursuant to 49 U.S.C. 5329(b). FTA began the process to establish these performance standards with the issuance of its Advance Notice of Proposed Rulemaking on Safety and Transit Asset Management,
1

but FTA has not completed this rulemaking. FTA will amend part 665 to establish those standards in a subsequent rulemaking. It is premature at this time for FTA to determine whether the existing safety tests will be incorporated into the new safety performance standards.

1
78 FR 61251 (Oct. 3, 2013).

The primary purpose of this NPRM is to seek comment on FTA's proposed bus minimum performance standards, bus model scoring system and pass/fail standard. In developing the proposals contained in this NPRM, FTA engaged in extensive discussions with transit industry stakeholders through the use of public webinars, teleconferences, and presentations at industry conferences. On March 28, 2013, FTA outlined the new statutory mandate in a public webinar held in conjunction with the Bus Testing Program Steering Committee meeting organized by the Larson Transportation Institute (LTI) of the Penn State University, the operator of the Bus Testing facility. On May 7, 2013, FTA presented its proposals at the Bus and Paratransit Conference organized by the American Public Transportation Association (APTA), and again in a public webinar on May 28,

2013, seeking comments on the proposed performance criteria, Bus Test Scoring System, and pass/fail Standard. In addition, LTI held a series of teleconferences in June 2013 with bus manufacturers to further address and refine the proposed performance standards, results scoring system and the pass/fail threshold. On September 26 and 27, 2013, FTA held two final public webinars to update stakeholders on the proposed performance standards, results scoring system and the pass/fail threshold and to solicit additional comments. Stakeholder contributions are reflected in the aggregate scoring system and pass/fail criteria contained in this NPRM. Participants in these public outreach efforts included transit vehicle manufacturers, component suppliers, public transit agencies, State departments of transportation, and FTA and Bus Testing Facility personnel.

In addition to implementing statutory mandates, FTA is proposing other administrative changes that would adjust the passenger payloading process to better reflect industry practice and ensure that buses tested at the facility comply with FTA Civil Rights and Buy America requirements regarding disadvantaged business enterprises and domestic content, respectively. FTA seeks comments on all of the proposals in this NPRM. In addition, FTA is seeking comment on establishing a bus testing requirement and scoring system for remanufactured buses sold by third parties and procured using FTA funds, which will be addressed in a subsequent rulemaking action.

C. Performance Standards by Test Category

In the current program, a standardized series of tests are conducted on new bus models and the results are published in a report for recipients to use for informing their procurement decisions.
2

There are no performance requirements that must be satisfied. The only “requirement” is that a new bus model have completed all of the tests required and that the test report has been published and received by the recipient prior to the disbursement of the FTA assistance for the bus procurement.

2

http://www.altoonabustest.com/bus-tests.htm

In formulating the proposed performance standards for the testing categories, FTA examined the test outcomes the testing center, located at the Larson Transportation Institute at Pennsylvania State University, currently reports for each test category to determine which of those were of such significance as to be considered “standards”. A “performance standard” is defined as a transit bus characteristic that, if not met at the minimum level, would singularly indicate a bus model was at a high risk of not being able to provide adequate transit service throughout its required service life. Due to national variations in the types of bus transit service, climate, bus route characteristics, and ridership preferences driving the recipient's need for continued bus specification flexibility, FTA's goal for the proposed performance standards was to identify a minimum set of requirements currently measured and reported by the Bus Testing Program that, once satisfied, enabled all FTA recipients to obtain transit buses that operate safely on bus routes with adequate automotive performance, with the ability to reliably withstand the rigors of transit service over its required service life and to do so without excessive operating costs and excessive negative impact to the environment. To achieve this goal, FTA reviewed existing documented bus performance standards, such the APTA Standard Bus Procurement Guidelines and current Federal regulations with applicability to the current test categories. For test categories where no external performance standards already exist, FTA formulated proposed standards based on the demonstrated test performance of bus models that proved to be unsuitable in actual service. FTA incorporated external performance standards and formulated new performance standards that applied equally to all bus models. FTA requests comments on the appropriateness of applying all the proposed standards equally to all bus models, and any alternatives that may produce more useful testing outcomes.

To guide the development of the criteria for the proposed standards, FTA analyzed the results from 49 bus testing reports published from January 2010 through February 2013 in addition to the results from specific bus models tested prior to that three-year window that did not meet their expected service life once placed into actual service. The compiled data set from past tests was used as the primary source for setting the proposed performance criterion values.
3

The proposed criteria in each of the five industry sourced performance standards (
i.e.,
interior noise, exterior noise, acceleration, gradeability on a 2.5% grade and on a 10% grade) were also compared to the demonstrated test results to verify the validity of each industry standard. In one case, in the Performance test category, the industry standard for the sustained speed on a 10% grade has never been met by any 60-foot bus model. As a result, FTA is proposing a lower performance level as the standard based on the fact that a higher performance level, while technically feasible, was not historically required by the procuring agencies when procuring non-standard vehicles such as a 60-foot articulated bus.

3
The test results plots used for the setting of performance criteria and standards are available in the docket for this rulemaking.

C.1. Structural Integrity

The useful life of a transit bus is ultimately determined by the life of the vehicle structure. The reason being that the structure is the backbone to which all other vehicle subsystems and components are attached.
4

The structural integrity test category examines a bus model's response to a range of structural stressors. Under the existing bus testing program, the structural integrity test category is comprised of seven sub-test categories: Shakedown, Distortion, Static Towing, Dynamic Towing, Jacking, Hoisting, and Structural Durability. Each sub-test category has one or more proposed performance standards. In total, these tests simulate how a bus responds to a variety of events that are expected to occur during the service life of a typical transit bus. No changes to the current structural integrity test procedures are being proposed. The results from the existing test procedures will be used to assess compliance with the proposed structural integrity performance standards. The agency requests comments on these specific tests, as well as whether there are any other tests the agency should include as part of the structural integrity performance standard. To the extent possible, please provide data, studies, or other similar information to support your comments.

4
U.S. Department of Transportation, Federal Transit Administration,
Useful Life of Transit Buses and Vans,
Booz Allen Hamilton, Inc. Report Number FTA VA-26-7229-07.1, April 2007.

C.1.1. Shakedown Test

The Shakedown Test currently requires loading and unloading a bus up to three times with 2.5 times its gross passenger load and measuring the amount of resulting permanent bus frame/body deflection (
i.e.,
flexing under load and not returning to its original shape) that occurs after each load cycle.
5

The purpose of the test is to verify an adequate factor of safety for structural strength. The first load cycle is intended to settle out the structure. After the second loading, the resulting bending of the structure is measured,

and if none of the measurements exceed 0.005 inch, the test is finished. If any of the measured bending exceeds 0.005 inch after the second load cycle, a third load cycle is conducted and the deflections are measured again. The resulting permanent bending is measured, and if none exceed an additional 0.006 inch, the test is complete.

5

http://146.186.225.57/bus_tests_pdfs/5-1.shakedown.pdf

FTA proposes that a tested bus model would meet the Shakedown Test performance standard if the resulting permanent deflection is 0.006 inch (0.005 inch plus 0.001 inch for measurement uncertainty) or less after a third loading cycle as measured according to the current test procedure. Vehicles with deflections in excess of 0.006 would receive a failing score in this category, resulting in an overall failing score. The compiled results for the Shakedown Test revealed that most buses were within this limit after the second load cycle, and all buses were within 0.005 inch or less after the third loading cycle.

Overall, there was a minimal amount of comments received during the outreach sessions regarding the proposed Shakedown performance standard. FTA received a written comment from one bus manufacturer indicating that there is no specific reason for the standard being set at ±0.005 inch when ±0.100 inch should provide a sufficient limit. FTA chose not to adopt this suggestion as the proposed standard because 0.005 inch, which was taken from the First Article Inspection Test of the American Public Transportation Association's Bus Procurement Guidelines, has been used as the threshold for many years and all previously test buses were capable of meeting this requirement. FTA lacks information regarding the benefits and costs of its proposed standard and the benefits and costs of the suggested ±0.100 inch Shakedown test standard. FTA requests comment on the benefits and costs of its proposed shakedown testing procedure and standard, the commenter's suggestion to use ±0.100 as the performance standard or other alternatives.

C.1.2. Distortion Test

The objective of the existing Distortion Test is to observe the operation of various subsystems when the bus is placed in a longitudinal twist (simulating operation over a 6-inch tall curb or through a 6-inch deep pothole) and subjected to a water spray mechanism simulating rain and traffic spray.
6

FTA proposes that a tested bus model would meet the Distortion Test performance standard if all of the passenger doors and emergency exits, while under every longitudinal twist test condition, operate and fully open in the same manner as they do with the bus on a level surface. FTA is not aware of problems in its recipient bus fleets related to bus body distortion performance and concludes that bus models that are capable of maintaining normal operation of the doors and windows while under the distortion loadings under this test are capable of providing adequate distortion performance when in service. Bus testing results for distortion shows no issues with test vehicles meeting this proposed standard. During the outreach efforts, bus manufacturers, transit agencies and others involved in the transit industry concurred with this performance standard as sufficient to demonstrate that the bus structure would not deform to the point of preventing the safe egress of the vehicle under this level of static loading. FTA requests comments on the benefits and costs of its proposed distortion testing procedure and standard, as well as on alternatives.

6

http://146.186.225.57/bus_tests_pdfs/5-2.distortion.pdf

C.1.3. Static Towing Test

The objective of the Static Towing Test is to determine the strength characteristics of the bus towing fixtures.
7

Having towing fixtures on the bus is essential for recovering buses that have gone off of the roadway and are immobilized. Without towing fixtures on the bus, vehicle recovery personnel would need to improvise a means of adequate mechanical connection to lift or pull the bus onto the road surface. This improvising can be dangerous to the recovery personnel and also can result in physical damage to the bus when a winch cable contacts the exterior bus in areas incapable of supporting those loads. Having towing provisions of adequate strength is also essential for the safe and effective recovery of immobilized buses.

7

http://146.186.225.57/bus_tests_pdfs/5-3.statictow.pdf

FTA proposes that a tested bus model would meet the Static Towing Test performance standard if no failure of the towing fixtures and connecting structure occurs at pulling loads up to 120 percent of the bus curb weight. Failure is defined as any visible permanent deformation, yielding, or bending of the provision or other structural component. Cracks in welds will constitute test failure. This proposed requirement is consistent with section TS 25 of the APTA Standard Bus Procurement Guidelines and is consistent with how the test has been conducted since the inception of the Bus Testing Program.
8

Under the current test procedure, a load equal to 120 percent of the bus curb weight is applied to the towing provisions using a hydraulic cylinder and a load distribution yoke. The load is applied to both the front and rear, if applicable, towing fixtures at an angle of 20 degrees with the longitudinal axis of the bus, first to one side then the other in the horizontal plane, and then upward and downward in the vertical plane. Any permanent deformation or damage to the tow eyes or adjoining structure is recorded.

8
“Standard Bus Procurement Guidelines RFP”, American Public Transportation Association,
http://www.apta.com/resources/standards/Documents/APTA%20Bus%20Procurement%20Guidelines.docx.

FTA believes that the current static towing test has served the industry adequately as we are aware of no in-service problems with the towing fixtures of buses that meet the requirement. FTA also believes that the current test is not burdensome as it is scaled according to the curb weight of the bus and the vast majority of buses have historically satisfied this requirement. All the buses in the data analysis used for this rulemaking satisfied the current test. During the outreach sessions, FTA received no specific comments regarding the proposed static towing performance standard. FTA seeks comment on the benefits and costs of its proposed static towing testing procedure and standard, and alternatives.

C.1.4. Dynamic Towing Test

The objective of this test is to functionally verify that the bus is towable with a heavy-duty commercial vehicle wrecker when following the manufacturer's instructions and using the manufacturer supplied towing interfaces (if any).
9

The test represents the situation where a bus is positioned on a roadway or similar surface but is not operational and must be towed to the maintenance facility. The recovery vehicle (wrecker) is maneuvered into place so the lifting apparatus (“stinger”) goes under the front of the bus and interfaces with front and rear treads of the front tires allowing the front of the bus to be lifted from the road surface. The bus is towed for 5 miles, decoupled from the tow vehicle and inspected for

any damage or loss of normal bus functions. FTA proposes that a tested bus model would meet the Dynamic Towing Test performance standard if a proper connection was made between the heavy-duty wrecker and the test bus and no damage occurred to the bus while being towed.

9

http://146.186.225.57/bus_tests_pdfs/5-4.dynamictow.pdf

While the proposed standard is not necessarily rigorous, as all buses in the data analysis were dynamically towable, it is very important that the bus is towable according to the manufacturer's instructions, that it is interoperable with common commercial vehicle recovery vehicles, and that no damage to the bus in is incurred during the dynamic towing exercise. During the outreach sessions, FTA received no comments regarding this proposed performance standard. However, FTA seeks comment on the benefits and costs of the proposed dynamic towing testing procedure and standard, and alternatives.

C.1.5. Hydraulic Jacking Test

The objective of this test is to assess the feasibility of hydraulically hoisting the bus with a portable hydraulic jack to a height sufficient to replace a deflated tire.
10

FTA proposes that the bus model would meet the Hydraulic Jacking Test performance standard if the bus can be safely raised and lowered using a portable jack, at each wheel position, to successfully replace a deflated tire without any permanent frame or body damage to the bus. This proposed standard is based on historic bus testing procedure and results for the jacking subtest. The proposed standard is also consistent with section TS 26 in the APTA Standard Bus Procurement Guidelines. During the outreach sessions, FTA received no comments regarding this proposed performance standard. However, FTA seeks comment on its proposed standard in this NPRM.

10

http://146.186.225.57/bus_tests_pdfs/5-5.jacking.pdf
.

C.1.6. Hoisting Test

The objective of this test is to assess for possible damage or deformation caused by the jack stands on the jacking pads.
11

FTA proposes that a tested bus model would meet the Hoisting Test performance standard if the bus can be hoisted and placed on jack stands without significant resulting permanent frame or body damage to the bus frame or bus body and that it is stable while on the jack stands. Up to 0.25 inch of plastic deformation of the frame structure directly at the point of jack contact will be allowed. Bulging or cracking anywhere on the frame or body structure while supported by the jack will constitute a failure. This proposed standard is based on the elemental need to be able to safely hoist a bus to enable the effective maintenance of the bus. The proposed standard is consistent with historic bus testing procedure and results for the hoisting subtest and is consistent with section TS 27 in the APTA Standard Bus Procurement Guidelines. FTA is not aware of any in-service hoisting issues with buses that have been tested and have met the proposed standard. There were no comments regarding this proposed standard during the industry outreach sessions. However, FTA seeks comments on the benefits and costs of its proposal, and alternatives.

11

http://146.186.225.57/bus_tests_pdfs/5-6.hoisting.pdf
.

C.1.7. Structural Durability Test

The objective of this test is to perform an accelerated durability test that simulates the cumulative road shock and vibration a transit bus experiences over 25 percent of its rated service life distance in miles.
12

The current Bus Testing Rule outlines five bus service life categories: four years or 100,000 miles; five years or 150,000 miles; seven years or 200,000 miles; ten years or 350,000 miles; and twelve years or 500,000 miles. The bus manufacturer specifies the service life category for the bus model submitted for testing. Once successfully tested, that bus model is eligible for bus procurements of the same service life length or less. FTA is not proposing any changes to these service life categories. The
Useful Life of Transit Buses and Vans
report from 2007 compared the actual bus retirement ages of buses in the various service life categories and found that the buses were being kept in service beyond their minimum service requirements. The results are shown in Table 3.

12

http://146.186.225.57/bus_tests_pdfs/5-7.durability.pdf

Table 3—Average Bus Retirement Ages
13

Vehicle category/minimum retirement age

Average
retirement
age (Years)

Share of active vehicles that are:
One or more years past the retirement minimum
Three or more years past the retirement minimum

12-Year Bus
15.1
19%
9%

10-Year Bus
*
7%
4%

7-Year Bus
8.2
12%
3%

5-Year Bus/Van *
5.9
23%
5%

4-Year Van
5.6
29%
10%

* Average retirement age estimates for this vehicle category is not available.

FTA

proposes a Structural Durability Test performance standard requiring that, at the completion of the Structural Durability Test, there are no “uncorrected” failures in the bus frame, body structure, and the propulsion system. An uncorrected failure is a failure that was detected during the test that has not been successfully eliminated through a design, manufacturing process, or quality control improvement and has been successfully validated with sufficient durability testing. Structural durability validation of powertrain failures is defined as 1.5 times the durability test distance from the accumulated test distance at the first occurrence of the failure, but no greater than an additional 100 percent of the original durability test length. FTA will bear 80 percent of the cost associated with one additional durability validation test if FTA believes that the proposed modification has merit and will pass the test on a subsequent attempt. Durability validation of frame and body structure

failures will require that the durability test is started over from the beginning after the application of the design or production process modification.

13
U.S. Department of Transportation, Federal Transit Administration,
Useful Life of Transit Buses and Vans
, Booz Allen Hamilton, Inc. Report Number FTA VA-26-7229-07.1, April 2007.

FTA strongly believes that a bus should not develop any significant failures or defects in the frame or body structure over the course of structural durability testing (the first 25 percent of its rated service life). There are several reasons for this belief:

(1) Structural cracks, structural bending, and structural failures that impede safe operation of the vehicle, delamination, and other material deteriorations could continue to propagate with continued shock and vibration input and other environmental exposure throughout the bus life.

(2) Cracks in structural elements may indicate that the bus design, materials, and/or manufacturing techniques are inadequate for transit service. With the proposed change in the bus payloading procedures contained in this notice, buses would no longer be tested in an “overloaded” condition beyond their Gross Vehicle Weight Rating (GVWR) or Gross Axle Weight Rating (GAWR) and, as a result, cracks in the frame or body would not be attributed to overloading.

(3) Repairs of structural and body cracks, deformation, or delamination may require specialized skills and tools that are beyond the capability of a common transit bus maintenance facility. Repairs of this nature can be expensive and outside the scope of the typical maintenance budget and can remove a bus from service for extended periods.

The proposed structural durability performance standard includes the chassis frame, the bus body structure, and all external and internal load-bearing elements that are either welded or adhesively attached to the frame and/or body structure. Major chassis or body structures that are primarily assembled using fasteners such as screws, bolts or rivets are also included in this performance standard.

FTA also strongly believes that a bus should not exhibit any propulsion system failures during the first 25 percent of its rated service life. Durability failures of the propulsion system are expensive to repair and cause disruptions in service. Failures of the bus powertrain revealed during the durability test will likely occur in actual transit service and may lead to more serious recurring problems later in its service life. Buses with systemic powertrain problems are often retired early due to their financial and operational liability to the operating transit agency. The proposed propulsion system durability performance standard includes but is not necessarily limited to all components of the energy/fuel storage, delivery, and management systems; engine or drive motor and related controller and management systems; power transmission systems (transmission, driveshaft(s), and drive axle(s)); and cooling systems. Certain essential proprietary off-board equipment required to operate advanced-technology buses may also be considered to be part of the propulsion system.

In setting the proposed durability performance standard, FTA desires to limit costs and risks. If FTA were to propose a more stringent standard, the length of the durability test would increase, which means that the costs of the testing program would also increase, and the cost of buses may increase as well and for no certain benefit. On the other hand, a less stringent testing standard that allows one or more uncorrected failures, or a less stringent testing procedure, would expose FTA and its recipients to greater risk. The existence of even one major uncorrected failure mode in the bus frame, body structure, or powertrain is enough to cause a bus to fail to meet its service life requirements. We note that some vehicles that would not have passed the proposed durability standard during testing have experienced problems once placed into transit service and have had difficulty meeting their specified service life, requiring more maintenance than is typical.

FTA believes that the proposed performance standards for durability are necessary and achievable. Overall, our analyses of the 49 recent tests indicate that there are examples of bus types and sizes of each group that have proven capable of satisfying the proposed performance standards. The analysis further indicated that six bus models experienced either structural failures or powertrain failures. Of those six, FTA believes that three would have needed additional durability testing after the design changes were applied. FTA, though, does not have information concerning whether subsequent production buses were changed as a result of the testing and requests comment on whether any of the 6 models that failed were modified prior to delivery to transit agencies.

FTA received comments regarding durability testing and the associated performance standards that are assessed from these test results (Durability, Reliability, and Maintainability). One commenter recommended that FTA provide the same 80 percent cost match for the test fees associated with additional durability testing. FTA is willing to provide the 80 percent cost match for any necessary additional durability testing. The commenter also requested that FTA commit to discussing the path forward for resolving a durability failure with the bus manufacturer within three business days. Another commenter highlighted the increased level of risk to a bus manufacturer of introducing new components and subsystems and new technology in general that the proposed standards for Durability, Reliability, and Maintainability create. FTA agrees that once a set of standards become effective, the risk to bus manufacturers, component suppliers, and technology developers may increase and that this is appropriate. The Bus Testing Program is the point-of-entry to the FTA bus capital program where bus models can be procured with FTA funding once testing is completed. Entities may use non-FTA funds to procure buses that have not completed and passed the testing program, but they do so at their own risk.

To encourage innovation, FTA has a prototype waiver policy available for the introduction of new bus technologies.
14

This waiver, if awarded, allows for up to five buses to be procured without the requirement for testing. FTA seeks comments regarding whether a new policy for the management of the risk associated with introducing new bus components and technologies to the new production models is needed once the final durability performance standards become effective. FTA is interested in suggestions regarding a graduated service life requirement and other strategies for sharing technological risk within the bus capital program.

14

http://www.fta.dot.gov/12351_8875.html

FTA seeks additional comments regarding the proposed Durability performance standards. FTA seeks comments on the benefits and costs of its proposed durability testing procedure and standard, and alternatives. Do commenters have information to determine the extent to which the proposed testing process reasonably simulates real-life use of buses? Does the current and proposed testing process result in manufactures using parts that are more or less durable than needed?

C.2. Safety

Currently, only a lane change stability test is performed in the Safety test category. However, since the objective of this test category is to document the safety performance of the test bus, FTA proposes to move the braking performance tests into the Safety test

category. Additionally, FTA proposes to address safety related bus failures identified during any of the tests in the Safety test category. Currently, the significant safety hazards are addressed in the Reliability test category. FTA believes that these tests should be included in the Safety test category because that while braking performance can be considered a bus performance issue and the existence of safety hazards can be considered for their Reliability impact, they are first and foremost related to safety. Table 4 outlines the current and proposed test categories for these tests.

TABLE 4—Current and Proposed Safety Sub-Test Categories

Subtest
Current test category
Proposed test category

Class 1 (safety hazards) Reliability Failures
Reliability
Safety

Stability
Safety
Safety

Braking:
Performance
Safety

Stopping Distance

Split Coefficient Surface

Parking Brake

Inserting them in the Safety test category will provide our recipients a greater holistic view of the safety of the bus. FTA seeks comments about moving the braking test result from the Performance test category and the Class 1 test results from the Reliability test category into the Safety test category. The proposed performance standards for the Safety test category are based on tests currently conducted and reported under the Performance and the Reliability test categories. No new tests are being proposed for the Safety test category in this notice. FTA notes that these tests are not intended to fulfill the mandate found in 49 U.S.C. 5329(b)(2)(C) that the agency promulgate minimum safety performance standards for transit vehicles. Once those standards are finalized via a separate rulemaking action, per section 5318(e)(1)(B)(ii), transit agencies will only be able to purchase vehicles using FTA funds that meet those standards. However, meeting those standards will not be included in the “pass/fail” score discussed in this rulemaking. Bus Testing Rule will be revised accordingly in order to accommodate the standards promulgated under 49 U.S.C. 5329(b)(2)(C). FTA proposes a total of five performance standards for the Safety test category.

C.2.1. Hazards

The first Safety performance standard titled “Hazards” addresses hazardous bus performance failures to include those failures that, when they occur, could result in a loss of vehicle control; serious injury to the driver, passengers, pedestrians, and/or other motorists; and/or property damage or loss due to collision or fire. The performance standard establishes that at the completion of testing there are no uncorrected Class 1 reliability failure modes remaining. Examples of Class 1 reliability failures include a loss of braking capability, a loss of power steering assist or all steering control, an unsecure windshield or side window failure, the failure of a passenger seat or seat mount, a fuel or other flammable fluid or gaseous substance leak, exposed or frayed electrical conductors, electrical short circuits, mechanical failures of energy storage system components and their mounting structures, and any instance of fire. Similar to the Durability test and Reliability test performance standards, an uncorrected failure mode is a failure that occurred during the test that has not been successfully eliminated through a design, manufacturing process, or quality control improvement that has been successfully validated through further testing. Validation of the corrected failure mode requires repeating all tests where the failure mode occurred. For Class 1 failure modes that occur during durability testing and were not classified as durability failures, sufficient validation is defined as 1.5 times the durability test length from the accumulated test length at the first occurrence of the failure mode, but no greater than an additional 100 percent of the original durability test length. This proposed standard is based on historic bus testing results for durability and reliability that have shown that most test vehicles have no issues meeting this proposed standard. FTA seeks comments on the benefits and costs of the proposed hazards testing procedure and standard, and alternatives.

C.2.2. Stability

The second proposed safety performance standard addresses the dynamic stability of the bus. The Bus Testing Program has used a double-lane change test procedure to assess the stability of buses. This obstacle avoidance maneuver procedure simultaneously challenges the roll stability, yaw stability, steering rate, the operator's workstation design, and the outward visibility of the bus.
15

The lane change maneuvers start at a speed of 20 miles per hour (mph) and continue up to a potential maximum of 45 mph. For each test speed, a bus must remain within the designated lane change test course and not experience any wheel liftoff from the road surface for the test run to be considered successful. For the Stability performance standard, FTA proposes that all buses must successfully negotiate the current lane change test course at a speed of at least 45 mph without lifting a wheel off the ground, striking any of the cones, or exceeding the boundaries of the test lane. This proposed standard reflects the current definition of success for the stability test and no current bus models have failed this requirement. FTA believes the proposed standard is appropriate as it tests the buses within the upper end of their operating speed spectrum. FTA is not aware of in service instability issues with buses that have satisfied this standard thereby providing an impetus for proposing a more stringent standard. FTA is not aware of reasons to propose a lower standard either.

15

http://146.186.225.57/bus_tests_pdfs/3.safety.pdf

FTA is aware of other test methodologies that examine the dynamic stability characteristics of medium and heavy vehicles. The single-lane change and the slalom course are operational-style tests that use the speed through the test course as the primary performance metric like the current double-lane change test. FTA feels that the double-lane change test is more appropriate as buses most often need to return to lane of travel they were operating within just before the obstacle avoidance maneuver and is therefore more operationally relevant. Similar to the double-lane change, the slalom maneuver alternates the dynamic lateral loading of the bus during the maneuver but the lack of a one lane width of lateral offset during the maneuver makes the test less representative of real-world conditions. FTA is aware of engineering tests that can be used to characterize specific bus stability parameters. The constant radius turn test is used to determine a vehicle's maximum lateral acceleration potential and its inherent propensity for understeering or oversteering behavior throughout its range of lateral acceleration. The “fishhook” and “sine-with-dwell” maneuvers can be used to induce vehicle instability in a vehicle and then assess the ability of the stability control system to manage the

response of the test vehicle. While these types of tests can provide significant insight into vehicle behavior they are not necessarily operationally relevant to transit bus consumers. Additionally, in order to execute these maneuvers, the use of vehicle safety outriggers, additional instrumentation, and potentially greater expanses of pavement surface are required which increases the cost and time required to conduct the tests. FTA has not analyzed the benefits and costs of these alternative testing procedures due to insufficient data, but FTA believes that the double-lane change test remains the best option for the needs of the Bus Testing Program. FTA received no specific comments regarding the proposed Stability performance standard during the industry outreach events.

FTA also acknowledges the National Highway Traffic Safety Administration's (NHTSA's) proposed rule to require electronic stability control on large buses under the proposed Federal Motor Vehicle Safety Standard (FMVSS) 136.
16

Under this proposed rule, all buses over 26,000 lbs gross vehicle weight rating (GVWR) would be required to have an electronic stability control system (ESC) with specific capabilities and a demonstrated ability to control the bus's stability within specified limits during a defined test maneuver that challenges the stability of the bus, forcing the ESC system to respond. The proposed requirements of FMVSS 136 do not apply to “urban” transit buses. Overall, if the requirements included in the proposal are finalized it is expected that some of the buses tested in this program will have an ESC system and some will not. FTA considered two different options for harmonizing the Bus Testing Stability performance standard with that of FMVSS 136.

16
“Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy Vehicles”, Notice of Proposed Rulemaking, National Highway Traffic Safety Administration, May 23, 2012,
https://www.federalregister.gov/articles/2012/05/23/2012-12212/federal-motor-vehicle-safety-standards-electronic-stability-control-systems-for-heavy-vehicles

The first option considered was replacing the current Stability test with the proposed FMVSS 136 tests and performance requirements for all buses. This option was rejected for several reasons.

1. For buses so equipped, ESC will ensure that they are stable. Our current stability test demonstrates whether a bus can safely execute a double lane change without reducing velocity. Without a minimum speed requirement that ensures a minimum level of agility, like that proposed for the double-lance change test, it would be possible for ill-handling buses to pass through the Bus Testing Program and enter transit service.

2. The estimated cost of executing the proposed 136 test is 5 times greater ($15,000 vs. $3,000) than the cost of the current Bus Testing program stability test. This new test would impact the program budget forcing FTA to reduce testing in other areas.

3. For buses without ESC, the test results would not be operationally meaningful. This reduces the value of the information to the transit industry.

Another option is test and apply the proposed Stability performance standard only to those bus models that do not fall under the scope of the proposed FMVSS 136 (urban transit buses and buses less than 26,000 lbs). Buses that are subject to FMVSS 136 and are certified as compliant by their manufacturer would be given an automatic pass for “Stability”. While this option is more practical for the test program, as it eliminates the need to conduct the FMVSS 136 tests, it still could allow a poor handling bus through the testing program. The proposed FMVSS 136 standard affects two types of buses that are used by transit; the over-the-road motorcoach, and the large Class 7 cutaway chassis buses. While it is unlikely that a motorcoach will be placed into regular fixed route transit service where a bus's agility is more important, some Class 7 cutaway buses are used for fixed route service.

Past Stability test results indicate that all bus models are capable of safely executing the double-lane-change test at 45 mph. As a result, FTA believes that probability of an ESC system intervening during this test is low for current production bus models. Therefore, FTA believes that applying the proposed Stability performance standard of 45 mph through the double lane-change test course to all buses, regardless of whether or not they are equipped with ESC, is the best option. However, since the inherent stability performance characteristics of future bus models are unknown, FTA seeks comments regarding the different options for integrating the proposed FMVSS 136 into the Bus Testing Program, including the benefits and costs and those of alternatives. FTA also seeks comments in general on the benefits and costs of its proposed Stability procedure and test, and alternatives.

C.2.3 Braking Performance

FTA proposes three performance standards for the braking performance of new bus models based on the test results obtained from the current brake performance tests.
17

The first is for the stopping distance on a dry level surface. The second is for the directional stability of the bus while stopping on a level split coefficient friction surface. The last one addresses the performance of the parking brake with the bus on a grade.

17

http://146.186.225.57/bus_tests_pdfs/4.2Performance-BrakeTest.pdf

C.2.3.1 Stopping Distance

The purpose of this test is to assess the straight line stopping capability of a bus model on a level high friction surface at initial speeds of 20, 30, 40, and 45 mph and on a level low friction surface at 20 mph. FTA proposes a stopping distance performance standard that every new bus model satisfies the stopping distance requirement of Federal Motor Vehicle Safety Standard (FMVSS) 105 Hydraulic and electric brake systems (49 CFR 571.105) and FMVSS 121 Air Brake Systems (49 CFR 571.121) of stopping within 158 feet from a speed of 45 mph on dry level road surface.

FTA proposes that although a bus model may fail to stop within 158 feet from a speed of 45 mph, a passing result from an applicable documented FMVSS 105 or 121 certification test conducted by an independent test organization can be used instead. FTA offers this alternative compliance option due to the fact that the Bus Testing Program does not conduct the brake burnish procedure specified in the FMVSS for the considerations of cost and time. The data analysis revealed that three of 49 buses recently tested would have failed this standard based on the Bus Testing results alone. Their average stopping distances from 45 mph were 160, 171, and 189 feet. FTA believes that these three failures could have been resolved through leveraging a FMVSS compliance test report or by repeating the brake testing, and that no mechanical changes would have been necessary in order to pass the proposed test.

After one of the outreach sessions, FTA received written comments from one source regarding the proposed stopping distance performance standard. The commenter recommended a braking distance performance standard of 200 feet from a speed of 45 mph for heavy-duty transit buses due to the fact that the FMVSS burnishing procedure is not conducted prior to conducting the

stopping distance tests. FTA believes that by allowing the use of an FMVSS certification test result as an alternate data source we have addressed the commenter's issue and at the same time not lowered the bar for braking performance below the FMVSS threshold. FTA seeks comments on the benefits and costs of proposed stopping distance performance standard, and alternatives.

C.2.3.2 Braking Stability

The purpose of the braking stability test is to determine the ability of a bus model to stay within a standard lane width during a maximum effort panic stop from 30 mph with one side of the bus on a high friction surface the other on a low friction surface. The proposed performance standard for braking stability is that the bus remains within a 12-foot lane width during the split coefficient friction brake stops as conducted under the current Bus Testing Program procedure. The data analysis revealed that all buses satisfied this proposed performance standard. FTA received no comments regarding braking stability. FTA requests comments on the benefits and costs of its proposed braking stability test procedure and standard, and alternatives.

C.2.3.3 Parking Brake

The third proposed performance standard is that the parking brake holds the bus stationary on a 20-percent grade while facing uphill and downhill for 5 minutes each in accordance with FMVSS 105 and 121.

The data analysis revealed that all buses satisfied this proposed performance standard. FTA received no comments regarding the parking brake performance standard.

C.3. Maintainability

The objective of this test is to examine the amount and types of maintenance required to keep the test bus in a fault-free operating state. Selected components (
e.g.
, transmission, alternator, windshield wiper motor, and other comparable components that serve the same functions replaced over a vehicle's lifespan on the bus) are removed and replaced, and the total time required to complete this task is recorded.
18

The amount of time necessary to conduct the scheduled servicing, as defined by the bus manufacturer, is recorded throughout the duration of the test. All unscheduled maintenance activities (
i.e.
, failures the occur during the testing) are documented as well, including the length of time for each maintenance action, as transit vehicle agencies noted unscheduled maintenance needs was a significant operating constraint.
19

18

http://146.186.225.57/bus_tests_pdfs/1-3.replacementandrepairsubsystems.pdf

19

http://146.186.225.57/bus_tests_pdfs/1-2.servicing_pm_and_repair.pdf

FTA proposes a maintainability performance standard for the total unscheduled maintenance time of no greater than 125 hours over the full course of all of the tests. Unscheduled maintenance time is a function of the reliability of the bus and the amount of labor required to resolve its malfunctions and is a significant indicator for the operating cost of the bus. FTA selected a standard of 125 hours after reviewing the bus testing results for all bus models that meet the proposed reliability performance standard (no more than two Class 2 reliability failures (a failure resulting in a maintenance road call to repair or tow the bus) and meet the proposed durability standards (no uncorrected frame and body structure failures or powertrain failures remaining at the completion of testing. during the test. Buses that required more than 125 hours of unscheduled hours during the test have been problematic in transit service and have usually not provided the full specified useful service life. Three buses from the study group of 49 would not meet this proposed performance standard. However, these same three bus models also fail the proposed durability requirements. Assuming the durability failures would be verified as “corrected” during the subsequent retesting, this proposed standard would likely be met.

FTA considered proposing a graduated performance standard based on the expectation that the amount of unscheduled maintenance is directly proportional to the amount of bus operation and hence its service life category. However, a plot of the total unscheduled maintenance results for buses with no greater than two Class 2 failures tested in 2010 revealed a uniform distribution of test results that was not directly proportional to the length of the service life. The proposed 125-hour standard would apply to all service life categories as all durability tests represent 25 percent of the vehicle's designated service life.

FTA received written comments from two sources on this subject during our outreach activities. One commenter recommended that specific limits need to be established for “consumable” parts so that shocks or bump stops are not replaced every 1000 miles to hide a deficiency in reliability during the test that could later impact the total unscheduled maintenance hours significantly. The commenter concurred with using a maximum of 125 hours for the unscheduled maintenance scale. The commenter also recommended having the component removal and replace times account for 20 percent of the points for this test category and the remaining points from the total unscheduled maintenance hours. FTA considered proposing limits on the replacement rates of certain “consumable” components but thought that limiting the total amount of unscheduled maintenance accumulated during the test was an adequate disincentive to “over-maintain” the bus. At the time of the comments regarding the component removal and replace times were submitted, FTA was considering a potential performance standard for this test or including it in the discretionary scoring for Maintainability. FTA chose not to propose including the component removal and replace (R&R) times in the pass/fail scoring system at all. FTA felt that the past test results that this metric did not show significant difference between bus models. Additionally, R&R times are only relevant if that component needs to be replaced multiple times throughout the bus's life. The R&R time for components that fail during the test are already captured in the unscheduled maintenance times.

Another commenter highlighted the concern that new bus models that introduce a new technology or even just a new component could significantly raise the risk of failing the test in the durability, reliability, or maintainability test categories. Overall, FTA agrees with this observation. The Bus Testing Program serves as the point of entry to unlimited bus production volumes for FTA recipients. These issues are already addressed in existing bus testing policies. The program's partial testing policies delineate between component changes that are “major” and need to be tested and those component changes that do not trigger additional testing.
20

Bus models employing new bus technologies may be eligible for a prototype waiver that allows a small quantity of buses to be procured without the need for testing.
21

20

http://www.fta.dot.gov/12351_8867.html

21

http://www.fta.dot.gov/12351_8875.html

FTA seeks additional comments concerning the benefits and costs of its proposed performance standard for Maintainability, as well as on alternatives. In addition, FTA seeks comment on whether the proposed 125-

hour standard may have adverse unintended consequences.

C.4. Reliability

The objective of this test category is to document and classify each of the operational reliability failures of a bus model while it undergoes the tests in the other test categories. As expected, most of the reliability failure incidents occur during the durability test portion of the structural integrity test category. However, all of failures throughout the test are documented. Specifically, the reliability failures are identified by subsystem and cumulative test distance at the time of failure, and the associated repair and down time for each failure is documented.
22

Table 5 is an example of the product of this analysis.

22

http://146.186.225.57/bus_tests_pdfs/2.reliability.pdf

TABLE 5—Reliability Analysis Example

Subsystem
Failure type
Class 4

Distance
(mi)

Class 3

Distance
(mi)

Class 2

Distance
(mi)

Class 1

Distance
(mi)

Maintenance labor-hours
Downtime

Drive System

821

2.0
1.0

1,857

2.0
6.0

1,860

4.0
24.0

1,860

6.0
12.0

6,542

8.0
24.0

9,725

25.0
144.0

14,252

20.0
2,712.0

The current bus testing program categorizes a failure during the test into one of the following four classes:

1. Class 1: A malfunction that could lead to a loss of bus control; in serious injury to the driver, passengers, pedestrians, or other motorists; and in property damage or loss due to collision or fire.

2. Class 2: A malfunction that results in test interruption because the bus cannot be operated. Service is discontinued until the bus is repaired at the site of the malfunction or it is towed to a service workshop. An in-service bus that experiences a Class 2 failure would require a road call (
i.e.
, a mechanical failure on the road that requires towing or repairs, but there is no immediate safety risk to the driver and/or passengers).

3. Class 3: A malfunction that results in temporary interruption of testing, and the bus must be returned to a service workshop for repair. An in-service bus that experienced a Class 3 failure could be driven safely to a rendezvous site for a bus swap.

4. Class 4: A malfunction that degrades bus operations but does not require immediate removal of the bus from testing. An in-service bus that experienced a Class 4 failure could complete its shift.

FTA proposes a reliability performance standard for the accumulation of no uncorrected Class 1 and not more than two uncorrected Class 2 reliability failure modes at the completion of the test. This proposed standard allows up to two Class 2 failures resulting from flat tires, failed coolant and hydraulic hoses, broken accessory drive belts, failed Starting, Lighting, and Ignition (SLI) batteries (common 12-volt batteries used for engine starting and general electrical system use, not traction batteries used for electric bus propulsion) or other externally sourced, high-volume components whose designs and quality control may be beyond the direct control of the bus manufacturers. This proposed standard is based on the past reliability test results for buses that did not have systemic problems with completing their service life requirements in service. The analysis of bus testing results indicates that one bus out of the 49 studied would fail the Class 2 requirement. However, FTA believes that had this requirement existed at the time of that test the manufacturer would have sought to remedy and validate at least one of Class 2 failure modes prior to the end of the test.

FTA chose to propose placing a performance standard for Class 1 reliability failures in the Safety test category and not in the Reliability test category so that these results would not be double-counted in the proposed Bus Model Scoring System. For completeness, the Reliability section of the test report will continue to report the details of all Class 1 failures. FTA also chose not to propose any performance standards for Class 3 and 4 reliability failures. The primary impact of these failure modes is increased unscheduled maintenance which is addressed with the proposed Maintainability performance standard. FTA seeks comments regarding the adequacy and reasonableness of the treatment of the Class 3 and Class 4 reliability test results.

FTA received written comments regarding the proposed Reliability performance standards. The commenter concurred with the proposed requirements of no uncorrected Class 1 and no more than two uncorrected Class 2 failures existing at the completion of the test. The commenter asked that FTA commit to a review of these failures, the proposed remedies, and the amount of validation test distance required within three business days to minimize the impact to the testing schedule. They also recommended that any additional testing required to validate design changes necessary to meet the Reliability performance standards be shared between FTA and the manufacturer at the same 80/20 percent split as the rest of the test. FTA seeks comments regarding the benefits and costs of the proposed Reliability performance standards, as well as on alternatives.

C.5. Fuel Economy

FTA proposes that the performance standard for the Fuel Economy test category is that every new bus model would satisfy the requirements of NHTSA's Medium and Heavy-Duty Vehicle Fuel Efficiency Program (49 CFR part 535) for the model year in which it is produced. In this program, transit buses are classified as “heavy-duty vocational vehicles” with voluntary standards starting with the 2013 model year and mandatory

standards starting in model year 2016. Correspondingly, this proposed performance standard becomes effective for the Bus Testing Program in 2016. Because buses will be required to comply with these regulations for model year 2016, this proposal would only have costs or benefits if recipients decide to purchase buses that perform better than the minimum standard based on the testing results. The current fuel economy testing conducted in the Bus Testing Program does not address this standard and would not be used for determining compliance. The manufacturer documentation used to demonstrate compliance with the NHTSA program would be the same basis for the Bus Testing Program determining compliance with its fuel economy standard. The Bus Testing Program fuel economy test results would be used to award additional points above the base score as is discussed in paragraph D.1.5 of this notice. No comments were received from stakeholders as this proposal was developed after the outreach sessions. Initially, FTA had proposed a set of minimum performance standards for fuel economy based on the test results produced by the program. FTA seeks public comment on the benefits and costs of its proposed fuel economy standard, as well as on alternatives.

C.6. Emissions

To protect public health and welfare, Congress enacted the Clean Air Act (CAA) and its subsequent amendments. The CAA Amendments of 1970 directed the Environmental Protection Agency (EPA) to use scientific data to set and revise national ambient air quality standards (NAAQS) for specific widespread and common pollutants, making major revisions in 1977 and 1990. Currently, the EPA has air quality standards in place for six common “criteria pollutants:” particulate matter, ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, and lead. Implementation of the standards is a joint responsibility of the States and EPA, with States responsible for developing enforceable State implementation plans that meet national standards. If a State fails to adopt and implement an adequate plan, EPA is required to issue a Federal implementation plan.

FTA proposes that the performance standard for the Emissions test category be that every new bus model would satisfy all of the applicable EPA exhaust emissions requirements for heavy-duty vehicles for the model year in which it is produced. Because buses are currently required to comply with these requirements, this proposal would only have costs or benefits if recipients decide to purchase buses that perform better than the minimum standard based on the testing results. The EPA divides heavy-duty vehicle exhaust emissions into two groups, criteria pollutants, and green-house gas pollutants. Exhaust emissions of nitrogen oxides (NO
X
), non-methane hydrocarbons (HC), particulate matter (PM), and carbon monoxide (CO) are considered “criteria pollutants” and the standards for governing these pollutants are provided in 40 CFR part 86. Exhaust emissions of carbon dioxide (CO
2
), methane (CH
4
), and nitrogen dioxide (N
2
O) are considered “greenhouse gas pollutants,” the standards for which are outlined in 40 CFR part 1037. Bus manufacturers currently leverage a “pass-through” compliance from the engine manufacturer, chassis manufacturer, or alternative fuel conversion supplier to demonstrate compliance with 40 CFR part 86. For the greenhouse gas emissions standard, 40 CFR part 1037, bus manufacturers must provide the bus models specific results generated by the Greenhouse Gas Emissions Model (GEM) to the EPA or leverage the chassis original equipment manufacturer (OEM) certification for those bus models built upon an incomplete OEM chassis.

While the Bus Testing Program currently measures all of these exhaust emissions except for N
2
O, the testing is conducted at the vehicle level using transit specific driving cycles and is not suitable for determining compliance with the EPA exhaust emissions requirements. The Bus Testing Program emissions test was designed to provide accurate data measured over transit specific duty-cycles to facilitate direct comparisons between bus models. Instead of using the Bus Testing Program emissions test results to address the EPA requirements, FTA proposes that the bus manufacturer documentation already being used to demonstrate compliance with the EPA requirements also be the basis for the Bus Testing Program to determine compliance with its Emissions performance standard. The Bus Testing Program emissions test results would be used to award additional points above the base score as is discussed in paragraph D.1.6 of this notice. FTA did not receive comments for this proposal as it was not discussed during the outreach sessions. FTA had initially proposed a performance standard for each category of exhaust emissions currently measured by the test program. FTA seeks public comment on the benefits and costs of its proposed emissions standard, as well as on alternatives.

C.7. Noise

The objective of this test category is to measure the noise levels inside and outside of the bus in various operating modes. There are a total of six different noise test procedures currently conducted. The interior noise testing includes measuring the ambient noise level inside the bus as it is being subjected to 80 dB of white noise from outside the bus, measuring the noise levels inside the bus as it accelerates from a standstill to 35 mph, and qualitatively identifies any specific types of noise such as rattles, wind noise, or resonant vibrations that occur at specific speeds, throttle positions, gear ranges, etc. The exterior noise testing measures the noise levels projected into the outside environment from the bus as it accelerates from a steady speed at full throttle, as it accelerates from a standstill to 35 mph under full throttle, and when stationary with the engine at three different throttle settings. FTA plans to continue testing and reporting on the six different noise test procedures as is current practice. However, performance standards are not proposed for all six tests.

To formulate Noise performance standards, FTA reviewed the test results for buses tested in 2010 and later. FTA also reviewed the APTA Standard Bus Procurement Guidelines and its recommended specifications for bus noise performance, as well as from other Federal agencies such as the National Institute for Occupational Safety and Health (NIOSH), the Federal agency responsible for workplace safety research, and the EPA, the Federal agency responsible for environmental health standards.

FTA found that while the APTA guidelines set an interior noise threshold of 80 dB(A) (decibels, A-weighted—a relative measure of the loudness of sounds as perceived by the human ear) for passenger seating locations and 75 dB(A) for the driver area, they were designed to address procurements of urban transit buses between 30 and 60 feet in length and do not address buses of shorter length, such as cutaway buses, which are of a different body design and whose engines are typically located forward in the cab of the vehicle, rather than in the rear of the bus.

FTA examined other noise performance standards to determine whether elevating the driver area noise level above 75 dB(A) posed an unacceptable hazard for the driver. The

NIOSH recommended exposure limit (REL) for occupational noise exposure is 85 dB(A), over an 8-hour time-weighted average. Exposures at and above this level are considered hazardous by NIOSH. Although bus drivers can be exposed to interior bus noise for 8 hours a day, the bus noise level is transient, peaking only during acceleration. Thus, setting the performance standard at 80 dB(A) would ensure that the NIOSH recommended exposure limit is not exceeded.

The APTA exterior noise threshold of 83 dB(A) while accelerating from a full stop is consistent with EPA regulation, which addresses transient external noise levels by commercial vehicles found in section 202.20(b) of 40 CFR part 202. This section provides: “No motor carrier subject to these regulations shall operate any motor vehicle of a type to which this regulation is applicable which at any time or under any condition of highway grade, load, acceleration or deceleration generates a sound level in excess of 83 dB(A) measured on an open site with fast meter response at 50 feet from the centerline of lane of travel on highways with speed limits of 35 mph or less; or 87 dB(A) measured on an open site with fast meter response at 50 feet from the centerline of lane of travel on highways with speed limits of more than 35 mph.” The current Bus Testing program conducts this test in the same manner at a speed up to 35 mph.

Therefore, FTA proposes that the interior and exterior noise measured during the maximum acceleration of the test bus from 0 to 35 mph would be basis for the noise performance test.
23 24

The proposed performance standard would be 80 dB(A) for interior noise throughout the interior of the vehicle and 83 dB(A) for exterior noise as measured by the current test procedures. The noise test data analysis of 49 recent bus models indicates that two cutaway chassis buses exceed the proposed interior noise performance at the driver's position by 4 dB (measured 84 dB versus the 80 dB limit). FTA believes that this level could be reduced to 80 dB or lower by the application of sound absorption materials between the engine compartment and floor areas and the driver's workstation. FTA requests comments on the cost of adding this sound absorption material to a bus. None of the 49 buses would fail the proposed exterior noise performance standard.

23

http://146.186.225.57/bus_tests_pdfs/7-1.interiornoise.pdf

24

http://146.186.225.57/bus_tests_pdfs/7-2.exteriornoise.pdf

FTA received some verbal and written comments regarding the noise testing and the proposed performance standards. During the earlier outreach sessions, FTA had discussed the proposed performance standards that it was considering for each of the six noise tests that are currently performed. Comments from transit agencies indicated that they focused on the noise test results for the noise produced when a bus is accelerating from a stop. One bus manufacturer concurred with the proposed noise test performance standards. FTA seeks comments concerning the benefits and costs of its proposed Noise performance standards and testing procedures, and alternatives.

C.8. Performance

The objective of this test is to investigate and document the automotive performance of the bus including its maximum speed, acceleration, and gradeability (grade climbing ability). These three factors are critical for buses to perform as needed for transient recipients: speed is important if the bus will be used in commuter service on highways, acceleration is important after being stopped or when entering traffic, and gradeability is important for those cities not located on flat terrain.

FTA is proposing three performance standards for the Performance test category: one for acceleration, and two for gradeability. A performance standard for the maximum speed on a level road surface is not proposed. The stability performance standard in the Safety test category already requires all buses to be able to maintain 45 mph throughout the lane change test. FTA believes that 45 mph is an adequate maximum speed that all transit buses need to satisfy. FTA understands that there are bus routes that require a speed greater than 45 mph. The Bus Testing Program requirements do not preclude transit agencies from procuring buses with a speed capability greater than 45 mph.

The proposed Acceleration performance standard would establish that every bus be capable of achieving a speed of 30 mph from rest in no greater than 18 seconds, which is consistent with Standard 7.3.1, Table 3, of the APTA Guidelines. FTA does not know the original basis for the acceleration requirement. Our speculation is that, when it was formulated, it was based on the capability of a popular bus model that transit agencies felt provided adequate performance.

The proposed Gradeability performance standards would establish that every bus shall be capable of sustaining at least 40 mph on a 2.5 percent grade, and at least 10 mph on a 10 percent grade. The proposed gradeability on a 2.5 percent grade performance standards is sourced from the APTA Standard Bus Procurement Guidelines. While this same source recommends a minimum speed of 15 mph on a 10 percent grade, FTA proposes a performance standard of 10 mph on a 10 percent grade to account for the typical measured test performance of the 60-foot articulated buses and to allow manufacturers to optimize the powertrain fuel economy of 40-foot buses for transit applications that do not require significant gradeability performance.

These proposed performance requirements are not particularly rigorous as they were set to allow for the optimization for fuel economy, given transit agency requirements. Additionally, as with any of the tests proposed today, these performance standards do not preclude transit agencies from procuring bus models that have greater performance capability. These proposed standards are consistent with bus testing results that have shown that most test vehicles would likely not have significant difficulty meeting these proposed standards.

The data analysis of the acceleration results for 49 recent bus tests showed that two buses failed to meet the proposed acceleration standard. One, a full electric bus, recorded a time of 18.6 seconds. FTA believes that with a software adjustment to the powertrain control system this particular bus could have reduced its acceleration time to 18 seconds or less. This adjustment would not have a significant cost. The other bus, a 60-foot articulated bus, achieved 30 mph in 19.6 seconds. This diesel-powered bus was equipped with a relatively small displacement engine for the 60-foot bus class. A numerically higher final drive ratio could have been fitted to the bus to reduce its acceleration time, as well as improve its gradeability, at the expense of maximum speed and fuel economy, but no additional equipment cost.

The data analysis for maximum speed on a 2.5 percent grade indicates that all 49 buses would satisfy the proposed requirement of 45 mph. A few buses were just at the threshold of this requirement. The data analysis for the maximum speed on a 10 percent grade reveals that three buses, one 40-foot diesel, one 40-foot electric, and the same 60-foot bus that failed the acceleration requirement failed to achieve 10 mph on a 10 percent grade. Of these three, the 40-foot diesel was the closest, at 7.5 mph, to achieving the

proposed standard. Other 40-foot buses with similar powertrains were capable of meeting this requirement, perhaps indicating that the engine in this particular bus was not operating at full capability. The next slowest bus was an electric bus performing at 5 mph. This particular bus has been confirmed by one operating agency as having poor hill climbing ability, making it unsuitable for several routes in their area.

FTA received several comments and recommendations regarding the proposed acceleration and gradeability performance testing and standards. During the outreach sessions, bus manufacturers endorsed the proposed acceleration requirement as it competes directly with fuel economy performance, citing that they have never had a customer ask for more acceleration than the APTA standard but always have customers asking for more fuel economy. Several bus manufacturers disagreed with the proposed gradeability requirement of 15 mph on a 10 percent grade for heavy-duty buses as most U.S. roadways are limited to a 6 percent grade. One manufacturer provided a summary of the buses tested that could not achieve 15 mph on a 10 percent grade. Two bus manufacturers recommended that FTA and LTI find a new method of determining gradeability performance as the current analytical method that uses the acceleration cannot account for how the new adaptive transmissions perform when the bus is on an actual grade leading to potentially erroneous test results. Based on these comments and its own data analysis, FTA adjusted the performance requirement for speed on a 10 percent grade down to 10 mph. Additionally, FTA and LTI have been working towards a new gradeability testing methodology using the chassis dynamometer to replicate the grade specific gravitational forces. However, we are not yet ready to propose this methodology. FTA seeks comments regarding the benefits and costs of its proposed acceleration and gradeability performance standards, as well as on alternatives.

D. Bus Model Scoring System

MAP-21 requires that FTA include a Bus Model Scoring System that produces an aggregate score that uses test categories and considers the relative importance of each such testing category. FTA proposes a scoring system where the maximum aggregate score is 100 points. The scoring system and maximum points available in each test category are shown in Table D.1. The points available in each test category reflect FTA's concerns as the primary provider of Federal assistance for the procurement of new bus models—namely, that they can operate safely on bus routes with adequate automotive performance, reliably withstand the rigors of transit service over their required service lives and to do so without excessive operating costs and excessive negative impact to the environment. The other test categories required in MAP-21 and proposed today, including noise, emissions, and fuel economy, are also of great importance for the agency, transit agencies and the public, but, as noted, are within the primary regulatory responsibilities of other Federal agencies.

A total of 54 points has been proposed across test categories that assess the capability of a bus model to reliably withstand continuous transit service for the duration of its service life, with only a reasonable level of maintenance required to sustain a state of good repair (structural integrity—30 points, maintainability—16 points, and reliability—8 points). A total of 20 points is assigned to safety, another FTA priority. The environmental sustainability characteristics of fuel economy and emissions are assigned 7 points each. Bus noise characteristics are assigned a total of 7 points. Lastly, the automotive performance characteristics of bus models are assigned a total of 5 points. FTA requests comments on its proposed scoring system. In particular, FTA seeks information on whether there are alternative scoring systems that would better enable recipients to compare buses, and whether categories should be weighted differently.

TABLE D-1—Weighted Test Results Scoring System

Test category
Potential awarded for meeting each performance standard

Potential points for performance above the
standard

Total point weighting by
category

Shakedown
1.0

Distortion
1.0

Static Towing
1.0

Structural Integrity
Dynamic Towing
0
1.0
30

Jacking
1.0

Hoisting
1.0

Durability-Structural
12.0

Durability—Powertrain
12.0

Hazards
10.0
0

Safety
Stability
2.5
0
20

Braking
5.5
2.0

Maintainability
Total unscheduled maintenance hours
2.0
14.0
16

Reliability
Number of Class 2 reliability failures
2.0
6.0
8

Liquid fuels

CNG

Fuel Economy
Hydrogen
1.0
6.0
7

Electric

CO
2

4.0

CO

0.4

Total hydrocarbon

0.4

Emissions
Non-methane hydrocarbon
1.0
0.4
7

Nitrogen oxides

0.4

Particulates

0.4

Noise
Interior Noise (0-35 mph)
0.5
3.0
7

Exterior Noise (0-35 mph)
0.5
3.0

Acceleration 0-30 mph
1.5

Performance
Gradeability 2.5%
1.5
0
5

Gradeability 10%
2.0

Total

60
40
100

Determination Of Scores By Test Category

FTA proposes that the test results for each proposed performance standard be used to generate the score for each test category. To receive a numerical score, a bus model must satisfy each proposed performance standard at least at the minimum level. FTA proposes scoring of the results in two steps: First a base score is awarded for the satisfaction of each performance standard; second, additional prorated points would be awarded when the performance of the bus model exceeds specific performance standards in the Safety, Maintainability, Reliability, Fuel Economy, Emissions, and Noise test categories as identified in Table D-2. FTA believes that while bus models that only just satisfy the performance standards at the minimum level should be capable of providing adequate transit service, performance above the performance standard in fifteen specific areas provides additional benefit to transit through increased safety and reliability, reduced operating costs and reduced negative impact on the environment. In these fifteen prorated performance categories, FTA believes that the maximum identified performance levels would not be exceeded by any current bus model. Additional details on the scoring of test results by test category are provided in the following sections.

EP23JN15.000

EP23JN15.001

D.1.1. Structural Integrity Tests

FTA believes that no discretionary points are available for performance above the standard because of a transit vehicle must meet these baseline requirements in order to meet its expected service life.

D.1.2 Safety Tests

The proposed scoring of the Safety Test is as shown in Table D-2. A total of 2.0 discretionary points are available. The Safety Test sub-categories are a collection of safety related bus characteristics that are currently examined in other test categories. Under the current rule, only the Lane Change

Stability Test is included in the Safety test category. The first proposed Safety test sub-category is Hazards. The performance standard for Hazards would require that all bus models have no Class 1 failures at the completion of the test that remained uncorrected. Bus models that satisfy this requirement would receive 10 points. The Stability performance standard would require that a bus model achieve a lane change speed of no less than 45 mph with the bus under control and all wheels on the ground throughout the maneuver. A bus that satisfies the stability standard would receive 2.5 points. There are three safety test sub-categories addressing the braking performance of a bus model. The first Braking performance standard would require the bus to stop from 45 mph in no greater than 158 feet. Bus models that require less than 158 feet to stop would receive 0.5 base points and up to an additional 2.0 prorated points if the bus stops in 80 feet or less. The average test result from this report would be used to award the score. The second Braking performance standard addresses the ability of a bus model to remain within a 12 foot road lane width during a split coefficient brake stop. A bus model that stays within the lane of travel during the stop would receive 2.5 points. The third Braking performance standard addresses the ability of the parking brake to hold the bus stationary on a 20-percent grade while facing uphill and downhill for 5 minutes each. Bus models that satisfy this requirement would be awarded 2.5 points.

D.1.3. Maintainability Test

The proposed scoring of the Maintainability Test is shown in Table D-2. A total of 16 points is available in this category. The maintainability performance standard would be set at no greater than 125 hours of unscheduled maintenance activity over the course of the test. All bus models that accumulate no more than 125 hours of unscheduled maintenance would receive 2.0 base points.

FTA believes that maintainability performance above the level set by the performance standard provides additional benefit to the transit industry. FTA is proposing that bus models that accumulate no unscheduled maintenance hours during the test would receive an additional 14 points. Test results between 125 and zero hours would receive an additional prorated amount of points between 0.0 and 14.0. For example, a bus that accumulated 25 hours would receive 13.2 points (2.0 + (125-25)/125)*14 = 13.2) and a bus that accumulated 100 hours would receive 4.8 points (2.0 + (125-100)/125)*14 = 4.8).

D.1.4. Reliability Test

The proposed scoring of the Reliability Test is shown in Table D-2. A total of eight points are available in this category. The proposed performance standard allows for accumulation of up to two uncorrected Class 2 failures at the completion of the test. All bus models that have two uncorrected Class 2 failures or fewer would receive 2.0 base points.

FTA believes that reliability performance above the level set by the performance standard provides additional benefit to the transit industry such as fewer road calls and service disruptions. As a result, FTA is proposing that if a bus model accumulated no Class 2 failures throughout the test it would receive an additional 6.0 points. A bus model that accumulates one uncorrected Class 2 failure would receive a total of 5.0 points (2.0 base points + 3.0 prorated points) by linearly prorating the points between two and zero failures.

D.1.5. Fuel Economy Test

The proposed scoring of the Fuel Economy Test is as shown in Table D-2. A total of 7.0 points is available in this category. The proposed scoring is a summation of the base score awarded for satisfying the applicable vocational vehicle fuel efficiency requirements from 49 CFR part 535 and the additional points awarded based on the results of the Bus Testing Program fuel economy test.

The fuel economy testing would consist of operating the new bus models on a chassis dynamometer over three different driving cycles (Manhattan, Orange County Bus Cycle, and the Heavy-Duty Urban Dynamometer Driving Schedule (HD-UDDS)). The driving cycles were selected during the emissions test development process to simulate a range of transit bus operating routes.
25

All new bus models would be tested over these cycles regardless of their weight or passenger capacity. During the test, only the energy consumed to provide bus propulsion would be measured. The fuel efficiency impact of heating or cooling the bus interior, while potentially significant, would not be evaluated during the test as the test facility does not provide a controlled ambient environment in the dynamometer facility.

25
West Virginia University, Center for Alternative Fuels, Engines & Emissions,
Transit Vehicle Emissions Program,
Dr. Scott Wayne, FTA Project No. WV-26-7008, May 2013.

The fuel economy testing accommodates a wide range of fuel sources and propulsion technologies. Transit buses historically have been produced in relatively low volumes totaling about 5,000 units of all types annually. Due to these low volumes, the majority of buses rely on the medium and heavy-duty truck powertrain and incomplete chassis vehicle supplier marketplace from which to source their bus propulsion systems. The current OEM powertrain market supplies complete gasoline and diesel powered cutaway chassis for body-on-frame buses. The OEMs also supply diesel and natural gas engines combined with traditional mechanical (automatic) and hybrid-electric transmissions with energy storage systems for the heavy-duty urban transit bus manufacturers. Additionally, there are third-party alternative fuel conversion suppliers that provide compressed natural gas (CNG) and liquefied petroleum gas (LPG (propane)) conversions of OEM gasoline cutaway chassis used by the bus manufacturers. Hybrid-electric and full electric conversions of OEM cutaway chassis are also available in the market. Heavy-duty bus OEMs are now developing and producing their own full electric and hydrogen fuel-cell electric powertrains in low volumes.

FTA used the Bus Testing Program fuel economy results from 2010 and newer bus models to establish the proposed fuel economy and fuel consumption scoring scales. The test results for the 2010 and newer bus models reflect the current state of bus propulsion technologies that are compliant with current EPA emissions laws and their impact on transit bus fuel economy. FTA is proposing four different scales to score the fuel economy results based on the bus model fuel type: liquid fuel (gasoline, diesel, propane and liquefied natural gas); CNG; hydrogen; and electric. For each proposed scale, the minimum was based on the measured or estimated fuel economy/fuel consumption of the largest transit buses—that is, a 60-foot long articulated bus, for each fuel type category. The scale maximum of each fuel scoring category was based on actual or estimated maximum results for each fuel type category with an additional margin to allow for future improvements in fuel efficiency. In formulating the proposed fuel economy scoring system, FTA focused on the intended purpose of providing information for bus model procurement decisions and fleet-level decisions about fueling infrastructure investments and bus operations.

Commonly, bus procurement solicitations already specify the length, the passenger capacity, and the fuel type. It is unlikely that transit agencies would be comparing bus testing fuel economy results for buses of different fuel types and significantly different passenger capacities when reviewing bids. Bus fleet strategy parameters such as bus design type (heavy-duty urban, cutaway, or paratransit), passenger capacity, and bus fuel type are usually decided prior to issuing a bus procurement request for proposal (RFP). Once the desired fuel has been decided, minimization of the overall fuel cost is the objective. However, this cost includes several variables including the unit price of the fuel, the amortized cost of any fuel specific fueling infrastructure, and the fuel efficiency of the bus models over its intended transit routes. Of these considerations, only the fuel efficiency of the bus is addressed by the Bus Testing Program, as fuel prices—including alternative fuels and electricity—are subject to market forces. Fueling infrastructure requirements vary by the type of fuel used, the size of the bus fleet, and the characteristics of the bus routes. Due to the existence of these and many other variables that affect fuel operating costs FTA believes it is not critical to use an identical measure to score the fuel economy of the four fuel types.

FTA considered other fuel economy scoring systems recommended by the bus manufacturers and their powertrain suppliers. FTA considered a universal energy efficiency scoring scale like British Thermal Units (BTUs) per mile or diesel miles per gallon equivalent, etc. This type of scale was rejected as it does not take into account the other variables related to fuel cost (
e.g.,
regional pricing differences, availability of fueling infrastructure, etc.), the change in relative efficiency between fuel types when operating in extreme climates, particularly in cold climates, and due to the significantly greater efficiency of electric buses, the resulting loss in granularity of the scale would greatly minimize the difference in score between bus models of similar size and fuel type, which defeats the objective of the program. We also considered a passenger miles per gallon or equivalent fuel consumption version of this metric. This type of metric was rejected as it assumes that buses are always operating with a full passenger load, that it would show that larger buses are more efficient even though they consume more fuel, which is counter-intuitive to consumers. FTA believes this metric could motivate bus manufacturers to over-maximize the passenger capacity of their bus model submitted for testing. This metric would also penalize bus models submitted for testing that employed a seating layout that was optimized for passengers who use wheelchairs, as the resulting total passenger capacity would be lower than that of the same bus model optimized for seated or standing passengers. FTA considered a ton-miles per gallon metric but this was rejected as it again would indicate that heavier buses are more efficient even though they consume more fuel. Lastly, FTA considered the merits of establishing multiple scoring scales based on bus size or bus passenger capacity. This approach could further increase the granularity of the scoring, highlighting differences between similar bus models. However, this type of scoring system was rejected due to concerns about manufacturers artificially manipulating the characteristics of the test bus to gain entry into the category that had most advantageous scoring system.

The proposed base score for satisfying the performance standard is 1.0 point. The remaining 6.0 points would be determined based on one of the applicable scales for the dominant fuel type of the bus model. For liquid-fueled buses, the average miles per gallon measured would be scored from the range of 1 mile per gallon (MPG) to a maximum of 13 MPG. All bus models that average 1 MPG or less would be awarded the base points. Bus models that average 13 MPG or more would be awarded an additional 6.0 points. Test results between 1 and 13 MPG would be awarded a prorated score between 0.0 and 6.0.

All CNG-fueled bus models that consume an average of 50 standard cubic feet per mile (SCF/mile) or more would receive the base score. An additional 6.0 points would be awarded for a test result of 10 SCF/mile or less. (Note: since the SCF/mile metric is a consumption metric, numerically lower values of SCF/mile would indicate greater efficiency). Test results between 50 and 10 SCF/mile would receive an additional amount of points prorated between 0.0 and 6.0.

All hydrogen-fueled bus models that consume an average of 98 standard cubic feet per mile (SCF/mile) or more during the test would receive the base score. An additional 6.0 points would be awarded for a test result of 15 SCF/mile or less. Test results between 98 and 15 SCF/mile would receive an additional amount of points prorated between 0.0 and 6.0. The hydrogen scoring scale was developed by a relative comparison of the measured performance of hydrogen fuel-cell powered 40-foot buses during National Fuel Cell Bus Program demonstrations and scaling the results for a 60-foot bus model.

Bus models whose primary source of power is electricity would be scored based on the consumption metric of kiloWatt-hours per mile (kW-hr/mile). Test results of 3 kW-hr/mile or greater would receive the base score. Averaged test results of 1 kW-hr/mile or less would be awarded an additional 6.0. (Note: Since the kW-hr/mile metric is a energy consumption metric, not a fuel economy metric, numerically lower values of kW-hr/mile indicate greater efficiency). Test results between 3 and 1 kW-hr/mile would receive an additional score prorated from 0.0 to 6.0.

D.1.6. Emissions Tests

The proposed scoring of the Emissions test results is shown in Table D.-2. A total of seven points would be available in this category. The proposed scoring is based on a combination of satisfying the emissions performance standard and the test results for six measured emission products averaged over the Manhattan, Orange County, and HD-UDDS transit bus driving test cycles. A base score of 1.0 point would be awarded to each new bus model that meets all applicable EPA exhaust emissions standards. The remaining six points available are distributed among the six exhaust emission categories measured during the transit specific Bus Testing Program emissions test with 4.0 points available in the carbon dioxide (CO2) category and 0.4 points available in each of the five other categories of carbon monoxide (CO), total hydrocarbon (THC), non-methane hydrocarbon (NMHC), nitrogen oxides (NOx), and particulate matter (PM). The CO2 category was assigned 10 times the available points of the other categories due to the fact that, while it is now regulated by the EPA, the gross amount of these emissions is significantly greater than the others and CO2 emissions vary among similar size bus models based on their fuel type and propulsion technology. FTA would like to highlight the difference in CO2 emissions between bus models.

The scoring scale for each category of exhaust emissions was developed from the test results of the 49 bus models tested since 2010. These bus models represent the current state of production bus emissions performance. The results for all current bus models would fall within the range of the performance bounds proposed. Bus Models with overall test results for CO2 emissions of 4,000 grams per mile or greater would

receive the base score and an averaged test result of zero grams per mile will be awarded an additional 4.0 points. Averaged test results between 4,000 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 4.0. Test results for carbon monoxide emissions of 20 grams per mile or greater would receive the base score and an averaged test result of zero grams per mile would be awarded an additional 0.4 points. Averaged test results between 20 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 0.4.

Test results for total hydrocarbon emissions of 3 grams per mile or greater would receive the base score and an averaged test result of zero grams per mile would be awarded an additional 0.4 points. Averaged test results between 3 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 0.4.

Test results for non-methane hydrocarbon emissions of 3 grams per mile would receive the base score and an averaged test result of zero grams per mile would be awarded an additional 0.4 points. Averaged test results between 3 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 0.4.

Test results for oxides of nitrogen emissions of 2 grams per mile or greater would receive the base score and an averaged test result of zero grams per mile would be awarded an additional 0.4 points. Averaged test results between 2 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 0.4.

Test results for particulate emissions of 0.1 grams per mile or greater would receive the base score and an averaged test result of zero grams per mile would be awarded an additional 0.4 points. Averaged test results between 0.1 and 0 grams per mile would receive an additional amount of points prorated between 0.0 and 0.4.

D.1.7. Noise Tests

The proposed scoring of the Noise Test results is as shown in Table D-2. The Noise Test category would be worth a total of 7 points with 3.5 points assigned to interior noise level and 3.5 points to the exterior noise level. Both noise performance standards address the noise levels produced by the bus while accelerating from 0 to 35 mph at its maximum rate. Test results for interior noise at or below the performance standard threshold of 80 decibels would receive 0.5 base points and test result of 30 decibels would be awarded an additional 3.0 points. Test results between 80 and 30 decibels would receive an additional amount of points prorated between 0.0 and 3.0. Test results for exterior noise at the performance standard threshold of 83 decibels would receive 0.5 base points and test result of 50 decibels would be awarded an additional 3.0 points. Test results between 83 and 50 decibels would receive an additional amount of points prorated between 0.0 and 3.0.

D.1.8. Performance Tests

The proposed scoring of the three Performance Tests is as shown in Table D.2. A total of five points would be available in this test category. The first sub-category tests the acceleration from 0-30 mph. A bus that accelerates to 30 mph in no greater than 18 seconds would satisfy the performance standard and receive 1.5 points. The maximum sustained speed on a 2.5 percent grade is the next sub-category. A bus model that is determined to be capable of sustaining no less than 40 mph on a 2.5 percent grade would satisfy the standard and receive 1.5 points. The maximum sustained speed on a 10 percent grade is the next sub-category. A bus model that is determined to be capable of sustaining no less than 10 mph on a 10 percent grade would satisfy the standard and receive 2.0 points. No discretionary points were assigned to this test category. FTA believes that performance in this category above the proposed performance standards is not necessarily beneficial to all transit agencies.

D.2. Calculation of the Aggregate Score

The aggregate score would be the summation of all of the individual test sub-category scores. The raw aggregate score would be rounded to the nearest whole number by rounding down when the first digit to the right of the decimal point is below 5 and rounding up when the first digit to the right of the decimal point is 5 or greater. Table D-3 presents the scoring for two bus models within the study group, report numbers PTI-BT-1007 and PTI-BT-1108. Both buses are 40-foot heavy-duty diesel-hybrid electric bus models with a 12-year service life.

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E. Pass/Fail Standard

In order to allow an amount of discretionary points available that provides meaningful dispersion of test scores and to maintain the test category scoring weights consistent with the relative importance between test categories, FTA proposes a pass/fail standard of 60 points. Under the proposed Bus Model Scoring System, a total of 60 points is achieved when a bus model meets, but does not anywhere exceed, the minimum requirements of each of the performance standards.

With regard to the testing at issue in this rulemaking, in order for a bus to be eligible for FTA funding, MAP-21 now requires that it meet two criteria. First, under paragraph 5318(e)(1), FTA funding is allowed only if the “bus . . . met . . . performance standards for maintainability, reliability, performance (including braking performance), structural integrity, fuel economy, emissions, and noise, as established by the Secretary by rule.” That is, a bus would be required to at least meet the minimum standards proposed in today's NPRM. Second, under paragraph 5318(e)(2), the bus also would need to pass the proposed “Bus Model Scoring System” based on the bus' aggregate score. With the proposed pass/fail standard, FTA is choosing to link those two requirements. Without the two requirements being linked, FTA believes it would not be possible to establish a pass/fail standard that requires some level of performance above the minimum levels established by the performance standards. However, FTA seeks comment on whether or not there are alternatives to this approach. Additionally, FTA proposes that, to eliminate confusion for recipients, a bus model that fails to satisfy one or more performance standards would not be issued an overall score until the failures are resolved. This is necessary to prevent the situation where a bus model fails an essential performance standard but scored very high in one or more other categories, potentially elevating the aggregate score above 60.

E.1. Effective Date of Pass/Fail Requirements

The performance standards, Bus Model Scoring System, and pass/fail standard would become effective ninety days after the final rule is published and would apply to both new bus models and previously tested bus models subsequently produced with major changes that require partial testing. The date of the signed contract for testing would determine the applicability of the new rule to a bus model.

E.2. Resolving the Failure To Meet a Performance Standard

When a new bus model undergoing testing fails to meet any one of the minimum performance standards, testing would be halted, pending a review of the test result by the Bus Testing Facility operator, the FTA Bus Testing Program Manager, and the bus manufacturer. Except for the test categories of Structural Integrity Test, Maintainability Test, and Reliability Test, FTA proposes that for test results that achieve 95 percent or greater of the value set for the performance standard but fail to meet the standard, that the test would be conducted one additional time at no additional cost to the manufacturer. For failures to meet the performance standards in the Structural Integrity Test, Maintainability Test, and Reliability Test, FTA proposes that a manufacturer propose and implement a design remedy to directly address the failure and then repeat the test(s) necessary to validate the design remedy. The FTA Bus Testing Program would bear 80 percent of the costs associated with one re-test in these test categories. If the proposed bus modifications necessary to remedy a performance standard failure are considered a “major” change in configuration or component, additional testing may be required.

E.3. Scoring of New Partial Tests

Existing bus models that undergo major changes in configuration or component (as defined in 665.5) that would require partial testing after the effective date of this rule would be scored based on the results for the new tests conducted and on the older test results that did not need to be repeated. During the partial test determination process, FTA would review the existing test data for that bus model and may require the retesting in categories where the existing report indicates a f

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2015-14176. Public record. Not legal advice.
