Federal Motor Vehicle Safety Standards; Stopping Distance Requirements for Vehicles Equipped With Hydraulic Brake Systems

DEPARTMENT OF TRANSPORTATION

49 CFR Part 571

[Docket No. 93-07; Notice 3]

RIN 2127-AE21

Federal Motor Vehicle Safety Standards; Stopping Distance

Requirements for Vehicles Equipped With Hydraulic Brake Systems

AGENCY: National Highway Traffic Safety Administration (NHTSA),

Department of Transportation.

ACTION: Final rule.

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SUMMARY: This final rule establishes stopping distance performance

requirements in Standard No. 105, Hydraulic Brake Systems, for trucks,

[[Page 13298]] buses, and multipurpose passenger vehicles (MPVs) that

have a gross vehicle weight ratings (GVWRs) over 10,000 pounds and that

are equipped with hydraulic brake systems. The requirements specify the

distances in which different types of medium and heavy vehicles must

come to a complete stop from a speed of 60 mph on a high coefficient of

friction surface. The requirements are designed to reduce the number

and severity of crashes involving these vehicles.

This notice is one part of the agency's comprehensive effort to

improve the braking ability of medium and heavy vehicles. In another

final rule published elsewhere in today's Federal Register, the agency

is adopting identical stopping distance requirements for medium and

heavy vehicles that are equipped with air brake systems. In a third

final rule, that responds to the Intermodal Surface Transportation

Efficiency Act (ISTEA) of 1991, the agency is requiring medium and

heavy vehicles to be equipped with an antilock brake system (ABS) to

improve the lateral stability and control of these vehicles during

braking.

DATES: Effective Dates: The amendments become effective on March 1,

1999.

Petitions for Reconsideration: Any petitions for reconsideration of

this rule must be received by NHTSA no later than April 10, 1995.

ADDRESSES: Petitions for reconsideration of this rule should refer to

Docket 93-07; Notice 3 and should be submitted to: Administrator,

National Highway Traffic Safety Administration, 400 Seventh Street SW.,

Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Mr. George Soodoo, Office of Vehicle

Safety Standards, National Highway Traffic Safety Administration, 400

Seventh Street SW., Washington, DC 20590 (202-366-5892).

SUPPLEMENTARY INFORMATION:

I. Background

A. Brake Related Crashes

B. Braking Devices

II. NHTSA Activities

A. Regulatory History

B. Agency Research

C. Heavy Vehicle Safety Report to Congress

III. Agency Proposal

IV. Comments to the Proposal

V. Agency Decision

A. Overview

B. Stopping Distance Requirements

C. First Effectiveness Test

D. Second Effectiveness Test

E. Leadtime

F. Costs

I. Background

A. Brake Related Crashes

Medium and heavy vehicles1 are involved in thousands of motor

vehicle crashes each year. One of the most important factors that

contributes to these crashes is brake system performance. Crashes in

which braking is a contributory factor can be further subdivided into

(1) crashes due to brake failures or defective brakes, (2) runaways on

downgrades, due to maladjusted or overheated brakes, (3) crashes in

which vehicles are unable to stop in time, and (4) loss-of-control

crashes due primarily to locked wheels during braking.

\1\Hereafter, these vehicles which have a gross vehicle weight

rating (GVWR) of 10,000 pounds or more are referred to as heavy

vehicles.

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This final rule amending Standard No. 105, Hydraulic Brake Systems,

to establish stopping distance requirements for hydraulically braked

vehicles,2 and the companion final rule amending Standard No. 121,

Air Brake Systems (49 CFR 571.121), to reinstate stopping distance

requirements for air braked heavy vehicles, will reduce the severity of

or prevent crashes attributable to a vehicle's inability to stop in

time.3 In these crashes, the heavy vehicle's brakes function, but

do not stop the vehicle quickly enough to avoid a crash. One way to

reduce the severity or number of such crashes is to improve heavy

vehicle stopping performance by reducing the distance needed to stop a

vehicle. Even if crashes of this type were not totally prevented,

improvements in stopping distance performance reduce collision impact

speeds, and thus reduce crash severity.

\2\Hydraulic brake systems are used on most single unit vehicles

with gross vehicle weight ratings (GVWRs) of 26,000 pounds or less

and on many medium and heavy trucks and buses with GVWRs between

26,000 pounds and 33,000 pounds. Hydraulic brakes are available on

single unit vehicles with GVWRs up to 46,000 pounds, but are used to

a lesser degree with such vehicles. Heavy vehicles not equipped with

hydraulic brakes are equipped with air brake systems.

3Today's companion final rule to require heavy vehicles to

be equipped with antilock brake systems (ABS) will prevent braking-

induced loss-of-control crashes.

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The following estimates regarding heavy vehicle crashes are from

NHTSA's 1992 General Estimates System (GES) which is based on data

transcribed from a nationally representative sample of state police

accident reports (PARs) and the Fatal Accident Reporting System (FARS).

NHTSA estimates that in 1992 there were about 168,000 crashes involving

heavy combination vehicles (excluding truck tractors when operating

bobtail, i.e., without a trailer). These crashes resulted in about

13,600 injuries and 387 fatalities to truck occupants and about 51,500

injuries and 2452 fatalities to occupants of other involved vehicles.

For bobtail truck tractors alone, the agency estimates that there were

about 8,400 crashes resulting in about 1,200 injuries and 39 fatalities

to truck occupants and about 2,600 injuries and 178 fatalities to

occupants of other involved vehicles. For heavy single-unit trucks, the

agency estimates that there were about 192,600 crashes resulting in

about 15,700 injuries and 165 fatalities to truck occupants and about

48,300 injuries and 891 fatalities to occupants of other involved

vehicles. In addition, crashes involving heavy vehicles result in more

expensive and severe property damage than crashes involving light

vehicles.

It is very difficult to quantify the number of crashes in which a

vehicle's brakes are unable to stop the vehicle in time. NHTSA

estimates that in 1992 there were about 18,000 crashes involving heavy

combination vehicles (excluding bobtail truck tractors). These crashes

resulted in about 1,800 injuries and 57 fatalities to truck occupants

and about 8,400 injuries and 754 fatalities to occupants of other

involved vehicles. For bobtail truck tractors alone, the agency

estimates that there were about 260 crashes resulting in about 100

injuries and 7 fatalities to truck occupants and about 240 injuries and

48 fatalities to occupants of other involved vehicles. For heavy

single-unit trucks, the agency estimates that there were about 30,100

crashes resulting in about 4,200 injuries and 17 fatalities to truck

occupants and about 15,000 injuries and 276 fatalities to occupants of

other involved vehicles. The Final Regulatory Evaluation (FRE) provides

greater detail about how today's final rules will reduce injuries and

fatalities resulting from such crashes.

The agency emphasizes that not all inability-to-stop-in-time

crashes are preventable. Nevertheless, improvements to heavy vehicle

brake systems should prevent or reduce the severity of a significant

number of these crashes.

B. Brake Designs and Equipment

In order to understand the discussion of braking in this preamble,

it is necessary to be familiar with several devices employed in braking

systems. As explained in greater detail in the companion final rules

about stopping distances for air-braked vehicles and about lateral

control and stability, manufacturers have developed several devices

related to the braking of hydraulically-braked heavy vehicles,

[[Page 13299]] including load proportioning valves (LPVs) and antilock

brake systems (ABS). LPVs change the brake proportioning to the drive

axle after mechanically sensing the vehicle's load, and ABSs

automatically control the amount of braking pressure applied to a wheel

so as to prevent wheel lockup, thus increasing stability and control in

emergency stops. As explained in the companion notices, these devices

can also reduce stopping distances.

II. NHTSA Activities

A. Regulatory History

As initially promulgated, Standard No. 105, Hydraulic Brake Systems

(49 CFR 571.105), set performance requirements for motor vehicles with

hydraulic service brakes. (37 FR 17970, September 2, 1972.) The 1972

rule required, among other things, that heavy vehicles stop from 60 mph

within 245 feet when in the lightly loaded condition and within 553

feet under partial failure conditions. Some petitions for

reconsideration challenged the setting of stopping distance

requirements for hydraulically-braked vehicles that were more stringent

than those set for air-braked vehicles in Standard No. 121. While the

initial stopping distance requirement of 245 feet in Standard No. 121

was identical to Standard No. 105's requirement, Standard No. 121 was

later revised to require stopping within 258 feet and then 293 feet.

The requirements for air-braked vehicles were to become effective

on September 1, 1973, and those for hydraulic-braked vehicles, on

September 1, 1974. NHTSA extended the effective dates for the stopping

distance requirements in Standard No. 105 and Standard No. 121. (37 FR

3905, February 24, 1972; 38 FR 3047, February 1, 1973; 39 FR 17550,

17563, May 17, 1974.) Prior to the final effective date for Standard

No. 105, the amendments pertaining to heavy vehicles were withdrawn, so

the requirements for heavy hydraulic-braked trucks and buses never went

into effect. (40 FR 18411, April 28, 1975.) The agency concluded that

the requirements that were being withdrawn could not be justified ``on

the basis of the data available at this time.'' The agency noted that

its decision to withdraw the amendment implementing requirements for

vehicles other than passenger cars was based on uncertainty as to the

achievable safety benefits relative to the costs of meeting those

requirements, rather than on an explicit determination that the

requirements were not justified. Notwithstanding this decision, the

agency emphasized that ``truck braking is in many cases substantially

poorer than passenger car braking, and that the generally longer

stopping distances and the greater severity of truck accidents justify

a safety standard for these vehicles.''

There are two primary reasons for the substantial costs that would

have been involved in meeting those requirements. The first reason was

the level of stringency of the requirements: the stopping distance

requirement from 60 mph was 246 feet, which was the original

requirement implemented for air-braked vehicles in Standard No. 121

that was later revised to 293 feet. The second reason relates to the

state-of-the-art of hydraulic brake system technology in 1975 versus

that of today. As discussed in detail in the Final Regulatory

Evaluation (FRE), the requirements being implemented by this notice

will not require any changes in the design or performance of

hydraulically-braked heavy vehicles.

Since its decision in 1975 to narrow Standard No. 105's

applicability, NHTSA has issued several amendments extending its

applicability to certain types of vehicles. In 1976, the agency

extended the Standard's applicability to all school buses. (41 FR 2391,

January 16, 1976.) In 1981, it extended the standard's applicability on

a general basis (with some limitations) to trucks, all types of buses,

and MPVs with a GVWR of 10,000 pounds or less. (46 FR 55, January 2,

1981.) As for trucks, buses, and MPVs with a GVWR greater than 10,000

pounds, the agency extended the requirements for braking with partial

hydraulic system failures and power booster unit failures. However, the

service and parking brake performance requirements, including those for

stopping distances, have not been re-adopted for hydraulically-braked

trucks and non-school buses with GVWRs over 10,000 pounds. The reader

should refer to the February 1993 NPRMs and today's companion final

rules for a detailed discussion of the regulatory history.

These requirements have received a great deal of agency and

judicial attention. (58 FR 11009, February 23, 1993.) Along with

certain other provisions, the stopping distance requirements for air-

braked vehicles were invalidated by the United States Court of Appeals

for the 9th Circuit in PACCAR v. NHTSA, 573 F.2d 632, (9th Cir. 1978)

cert. denied, 439 U.S. 862 (1978).

While PACCAR involved air-braked vehicles, it is relevant to

hydraulically-braked vehicles as well. The stability and control final

rule contains a detailed discussion about PACCAR and how the agency has

responded to that decision. As mentioned earlier, the stopping distance

requirements in this final rule are significantly longer than those

that were rescinded in 1975.

However, as also discussed earlier, the same stopping distance

requirements that were implemented in 1975 for air-braked vehicles were

later extended to levels that are close to those included in this

notice. One significant difference between the original requirements in

1975 for hydraulically braked, heavy vehicles and those contained in

today's final rule is that the agency has decided to specify different

stopping distances for different configurations of heavy vehicles.

Today's requirements can further be distinguished from those

invalidated in the 1970s, since manufacturers will not need to

significantly redesign their brakes or use overly aggressive foundation

brakes to comply with today's requirements.

Even though the stopping distance requirements being specified in

today's final rule are less stringent for some vehicle configurations

than those invalidated by PACCAR for air-braked vehicles, the agency

believes that the braking requirements in today's final rules, taken as

a whole, significantly enhance the overall braking performance of

hydraulically-braked vehicles given the agency's decision to require

these vehicles to be equipped with ABS.

B. Agency Research

As part of its review of heavy vehicle braking, NHTSA issued a

report entitled ``NHTSA Heavy Duty Vehicle Brake Research Program

Report No. 4--Stopping Capability of Hydraulically Braked Vehicles''

(DOT HS 806 860, October 1985). That report was based on a

comprehensive testing of twelve hydraulically-braked vehicles ranging

in weight from 14,800 to 46,000 pounds in both the empty and loaded

conditions. The straight line stopping distance tests measured the

shortest possible stop within a 12-foot-wide lane without locking up

more than one wheel per axle or two wheels per tandem axle at speeds

greater than 20 mph. At 60 mph, stopping distances ranged from 214 feet

to 396 feet. Among other things, the agency found that the ability to

stop in a short distance without loss of control is primarily a

function of front/rear braking force distribution. Vehicles with brake

force distributions closest to their dynamic weight distributions were

the best performers. [[Page 13300]]

C. Heavy Vehicle Safety Report to Congress

In response to section 9107 of the Truck and Bus Regulatory Reform

Act of 1988, the agency submitted a report to Congress entitled

``Improved Brake Systems for Commercial Vehicles.'' (DOT HS 807 706,

April 1991)4 While the report focuses on air brakes systems, much

of the information is relevant to hydraulically-braked heavy vehicles.

After discussing crash data concerning heavy vehicle brake systems, the

report explained factors related to braking effectiveness and stability

and control during braking. The report mentioned that stopping

distances and vehicle stability could be improved by equipping heavy

vehicles with LPVs and ABS.

\4\The report may be examined at the agency's Technical

Reference Office, room 5108, at no charge. It is available from the

National Technical Information Service (NTIS), Springfield, VA 22161

for a small charge.

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III. Agency Proposal

On February 23, 1993, NHTSA proposed to amend Standard No. 105 to

establish different stopping distance requirements for different types

of heavy vehicles equipped with hydraulic brake systems, when making

stops from 60 mph on a high coefficient of friction surface. (58 FR

11003.) The agency tentatively concluded that establishing the same

stopping distance requirement for all heavy vehicles with fully

operational service brakes would be inappropriate, since it would be

too stringent for unloaded single unit trucks but not stringent enough

for buses. The proposed stopping distances were based on the agency's

analysis of the available data, especially the stopping distance

results in the VRTC reports.

NHTSA explained that its long-term objective is to upgrade the

braking efficiency of heavy vehicles to enable them to make controlled,

stable stops, under all loading and road surface conditions. The agency

believed that the proposed requirements would reduce the disparity in

stopping distance performance between heavy vehicles and passenger

cars, while assuring that the requirements' costs are reasonable. The

agency proposed stopping distance requirements for vehicles equipped

with hydraulic brake systems consistent with the stopping distance

requirements for air-braked heavy vehicles. These requirements would

take effect two years after issuance of the final rule. The agency

decided not to propose the first effectiveness test, which involves the

preburnish condition. However, it proposed the second effectiveness

test, where the vehicle is tested at its GVWR to assure full braking

power, and the third effectiveness test where the vehicle is tested in

the lightly loaded vehicle condition to assure reasonable brake

balance.

IV. Comments on the Proposal

NHTSA received 29 comments in response to the NPRM. Commenters

included heavy vehicle manufacturers, brake manufacturers, safety

advocacy groups, heavy vehicle users, industry trade associations, and

other individuals. The American Automobile Manufacturers Association

(AAMA) submitted joint comments on behalf of the eight major domestic

manufacturers of heavy vehicles: Chrysler, Ford, Freightliner, General

Motors (GM), Mack Trucks, Navistar, PACCAR, and Volvo-GM.

The commenters generally supported the agency's decision to

establish stopping distance requirements. However, they offered mixed

views about the specific stopping distances being proposed. GM,

Navistar, Heavy Duty Brake Manufacturers Council (HDBMC), and Rockwell

WABCO stated that the proposed stopping distance requirements are

appropriate. In contrast, the Insurance Institute for Highway Safety

(IIHS), the Coalition for Consumer Health, and Advocates for Highway

Safety (Advocates) believed that the required distances for trucks and

buses should be shorter. Advocates stated that the proposal did little

more than ``grandfather'' existing braking capabilities and therefore

would not result in the best available braking performance for large

trucks.

Commenters also addressed specific issues raised in the NPRM,

including the requirements' applicability to school buses, the need for

the first and fourth effectiveness tests, the vehicle test speed, the

test surface specification, the wheel lock up restrictions, the initial

brake temperature, the failed system test, the vehicle loading, the

parking brake test, the burnish procedures, and the implementation

schedule for the requirements. More specific discussions of these

comments, and the agency's responses to them, are set forth either

below or in the stopping distance rule for Standard No. 121.\5\

\5\The stopping distance rule for air-braked vehicles discusses

the issues of the test surface, wheel lock restrictions, initial

brake temperature, the failed system test, vehicle loading, the

parking brake test, and burnish procedures.

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V. Agency Decision

A. Overview

Based on the FARS and other crash data, test data from the agency's

heavy vehicle brake research program, comments to the NPRM, and other

available information, NHTSA has decided to amend Standard No. 105 to

establish stopping distance performance requirements for heavy vehicles

that are equipped with hydraulic brake systems. The requirements, which

apply to 60 mph stops on a high coefficient of friction surface,

specify different stopping distance requirements for three different

types of heavy vehicle configurations: (1) loaded and unloaded buses,

(2) loaded single unit trucks, and (3) empty single unit trucks. The

requirements are designed to standardize the distance needed for all

heavy vehicles to come to a complete stop, thereby reducing the number

and severity of crashes.

This notice is one part of the agency's comprehensive effort to

improve the braking ability of heavy vehicles. In another final rule

published elsewhere in today's Federal Register, the agency is adopting

identical stopping distance requirements for comparable heavy vehicles

that are equipped with air brake systems. The agency believes that it

is appropriate to specify the same stopping distance requirements for

similar vehicles. In a third final rule, the agency is responding to

the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 by

requiring heavy vehicles to be equipped with an antilock brake system

to improve the lateral stability and control of these vehicles during

braking.

B. Stopping Distance Requirements

Based on its testing at VRTC, NHTSA proposed different stopping

distances for various categories of vehicles, as follows:

Loaded and Unloaded Buses

280 ft.

Loaded Single-Unit Trucks

310 ft.

Empty Single-Unit Trucks

335 ft.

The agency reasoned that a single stopping distance requirement for

all heavy vehicles with fully operational service brakes would be too

stringent for unloaded single unit trucks, but not be stringent enough

for buses. Based on the VRTC test results, the agency anticipated that

manufacturers would not have to make changes to the hydraulic braking

systems of their vehicles to comply with the proposed stopping distance

requirements.

AAMA and most other industry commenters agreed with the stopping

distance values proposed for the various vehicle configurations. GM,

Navistar, [[Page 13301]] Heavy Duty Brake Manufacturers Council

(HDBMC), and Rockwell WABCO commented that they believed that the

proposed stopping distance requirements are appropriate. ATA agreed

with the proposal to specify different stopping distances for different

types and loadings of vehicles. It also agreed with specifying the same

stopping distances for the same types of air-braked and hydraulically-

braked vehicles under the same loading conditions.

In contrast, other commenters stated that the proposed stopping

distances were not sufficiently stringent. Advocates stated that the

proposed stopping distances simply ratify braking distances currently

achieved by manufacturers and do not seek to improve real-world braking

performance. It stated that except for the 280-foot requirement for

buses, the other proposed stopping distances are longer than the 293

feet established before PACCAR. Similarly, IIHS stated that the

proposals do not go far enough toward requiring the best available

braking for heavy vehicles.

Based on the public comments and other available information,

especially the VRTC test results, NHTSA has decided to specify

different stopping distances for three separate categories of vehicles,

when tested at a speed of 60 mph on a surface with a PFC of 0.9, as

follows:

Loaded and Unloaded Buses

280 ft.

Loaded Single-Unit Trucks

310 ft.

Unloaded Single-Unit Trucks

335 ft.

NHTSA believes that these stopping distances, combined with the

stability and control final rule, will ensure that heavy vehicles make

short stable stops within a reasonable distance. The agency further

notes that the companion notice to require heavy vehicles to be

equipped with antilock brake systems will also help to improve the

braking performance of those vehicles enough to enable them to comply

with the stopping distance requirements.

C. First Effectiveness Test

The first effectiveness test in Standard No. 105, which is commonly

known as the ``preburnish test,'' measures brake performance very early

in a vehicle's life. School buses are the only heavy vehicle type

currently subject to the first effectiveness test (and to Standard No.

105's other stopping distance requirements.)

In the NPRM, NHTSA did not propose applying the preburnish test to

other heavy vehicles. The agency stated that the first effectiveness

test would continue to apply to school buses, since it did not want to

modify the Standard's current requirements. The agency reasoned that

subjecting school buses (but not other heavy vehicles) to the first

effectiveness test was appropriate given the provisions in the vehicle

safety law pertaining to school buses (codified as 49 U.S.C. 301), and

the ``stop-and-go'' duty cycle of school buses. The agency requested

comment on whether to apply the first effectiveness test to heavy

vehicles in general and whether to retain the test for school buses.

AAMA, AlliedSignal, and HDBMC stated that heavy vehicles, including

school buses, should not be subject to the first effectiveness test and

the 30-mph second effectiveness test. AlliedSignal commented that

excluding hydraulically braked school buses from the first

effectiveness test would be consistent with the agency's intent for

consistency between hydraulically braked and air-braked vehicles.

AlliedSignal also stated that the intended usage of non-school buses

and school buses is nearly identical, and that chassis components are

nearly identical. AAMA commented that school buses and non-school buses

should have standardized braking requirements. AAMA disagreed with the

agency's statement that the school bus provisions of the law have a

bearing on the need for a first effectiveness or 30-mph second

effectiveness requirements for school buses. Straight-Stop and Arent

Fox recommended that transit buses and school buses be tested at speeds

typical of their normal use such as 20 to 30 mph. Chrysler agreed with

the agency's proposal not to apply the first effectiveness test to

heavy vehicles, except for school buses.

Advocates requested that the agency apply the first effectiveness

test to all hydraulic braked vehicles, not just school buses. It

claimed that the new non-asbestos linings tend to swell early in the

service lives of new brakes. As a result, it believed that the stopping

distance would be degraded during this period, a phenomenon that would

be detrimental to safety. Advocates argued that the agency cannot

arbitrarily dismiss the first effectiveness test with an assertion that

it is not aware of any ``green brake'' crashes.

After reviewing the comments and other available information, NHTSA

has decided not to apply the preburnish test to all heavy vehicles

equipped with hydraulic brakes. It has also decided that the test

should not apply to school buses. As explained in the NPRM, NHTSA is

not aware of any crashes involving hydraulically braked heavy vehicles

caused by ``green'' brake linings. Therefore, the agency has determined

that there is no need to apply the preburnish test to heavy vehicles.

The agency notes that its decision not to apply the preburnish test to

heavy vehicles results in the requirements in Standard No. 105 and

Standard No. 121 being consistent for similar vehicles given the

absence of a preburnish test in FMVSS No. 121 for air-braked school

buses.\6\

\6\The agency decided not to include a preburnish test in

Standard No. 135, reasoning that few vehicles are driven any length

of time in an unburnished condition.

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With respect to non-asbestos linings, NHTSA agrees that there is a

tendency for such linings to swell early in the life of the new brakes.

However, the agency has already addressed this issue in greater detail

in a NPRM on the brake adjustment procedure for brake burnish of heavy

vehicles (56 FR 66395, December 23, 1991). The agency concluded that

the swelling of the non-asbestos linings has no effect on their service

life or on the service brake performance of the vehicle.

D. Second Effectiveness Test

The second effectiveness test in Standard No. 105 assesses brake

performance when a vehicle is in its fully loaded condition. In the

NPRM, NHTSA proposed extending the second effectiveness test to

hydraulically-braked heavy vehicles. The agency explained that this

test replicates one of the most common loading conditions for heavy

vehicles. The agency tentatively concluded that it would be in the

interests of safety to establish stopping distance requirements for

hydraulically-braked heavy vehicles in the fully loaded condition (at

GVWR).

NHTSA notes that, unlike the requirements in Standard No. 121 which

specify 60-mph stops, the second effectiveness test includes 30-mph

stops as well as 60-mph stops. The agency proposed applying the 30-mph

test to school buses, since it is similar to their in-service stop-and-

go operation. Although there is no similar 30-mph road test for air-

braked school buses, the brake assemblies of these vehicles are

required to be tested on a dynamometer under section S5.4 of Standard

No. 121. These tests evaluate the capability of a brake assembly in a

stop-and-go duty cycle. Section S5.4.2, Brake Power, requires that the

brake be capable of making 10 consecutive decelerations from 50 mph to

15 mph at an average deceleration rate of 9 feet per second. Therefore,

the agency further believed that the 30-mph portion of the second

effectiveness tests should be retained for school buses only, given

their stop-and-go duty cycle. [[Page 13302]]

AlliedSignal was the sole commenter on the issue of the 30-mph

stopping distances. It stated that its testing of a current system

showed that the proposed requirement of 70 feet for the 30-mph second

effectiveness test would be difficult to meet without major brake

redesign. It therefore recommended that the requirement be increased to

at least 78 feet if the agency decides not to exclude school buses from

this test.

NHTSA has decided to apply the test requirement to school buses

with a stopping distance of 70 feet, as proposed. The agency notes that

no vehicle manufacturer objected to the proposed stopping distance

value. Further, NHTSA's test data (NHTSA Heavy-Duty Vehicle Brake

Research Program Report No. 4--Stopping Capability of Hydraulically-

Braked Vehicles) show that 70 feet is a reasonable requirement from 30

mph for the second effectiveness test.

NHTSA acknowledges that some transit buses have stop-and-go duty

cycles similar to school buses. However, such vehicles are typically

equipped with air brake systems, and would therefore be required to

have their brake assemblies dynamometer tested. The 30-mph second

effectiveness test would not apply to these vehicles because they are

not school buses.

E. Leadtime

In the NPRM, NHTSA proposed that the stopping distance requirements

become effective two years after the final rule's publication.

AAMA supported the proposed effective date, provided that the

agency incorporated its recommended modifications in the final rule.

Rockwell recommended that the stopping distance requirements and the

stability performance requirements be combined so that the effective

dates for both rulemakings are concurrent. Several commenters to the

stability and control NPRM, including AAMA, made the same suggestion.

AAMA noted that since ABS can have a direct influence on achievable

stopping distance, it is important to optimize brake system performance

by taking both stopping distance and stability into account.

On April 12, 1994, NHTSA published a supplemental notice of

proposed rulemaking (59 FR 17326) that proposed the following

implementation schedule for both the stopping distance and lateral

stability and control requirements:

Truck tractors

2 years after final rule (1996)

Trailers

3 years after final rule (1997)

Air-braked single unit trucks and buses

3 years after final rule (1997)

Hydraulic-braked single unit trucks and buses

4 years after final rule (1998).

The agency reasoned that making the effective dates for the two

rulemakings concurrent would facilitate a more orderly implementation

process, avoid the need for manufacturers to redesign the brakes on

individual vehicles twice, and reduce the development and compliance

costs that manufacturers would face as a result of these regulations.

NHTSA requested comments about the implementation schedule proposed in

the supplemental notice.

As the stability and control final rule discusses in detail in the

section titled ``Implementation Schedule,'' NHTSA has decided to adopt

an implementation schedule similar to the one proposed in the SNPRM.

Specifically, hydraulically-braked heavy vehicles manufactured on or

after March 1, 1999 will have to be equipped with ABS and comply with

the high coefficient of friction stopping distance requirements. The

agency has decided that these effective dates, which were widely

supported by vehicle manufacturers, brake manufacturers, and safety

advocacy groups, will provide for an efficient implementation of the

heavy vehicle braking requirements.

F. Costs

As indicated earlier, NHTSA does not anticipate the need for

vehicle manufacturers to change the design of the foundation brake

system of heavy, hydraulically braked vehicles in order to comply with

the requirements of this final rule. The only costs associated with

this rulemaking are those related to compliance testing costs. As

detailed in the FRE, the agency estimates these costs to be $1.030

million, or an average per-vehicle cost of $5.30.

Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

This rulemaking document was not reviewed under E.O. 12866. NHTSA

has considered the impact of this rulemaking action under the

Department of Transportation's regulatory policies and procedures. This

action has been determined to be not ``significant'' under those

policies and procedures.

A FRE setting forth the agency's detailed analysis of the benefits

and costs of this rulemaking (along with the other rules issued today)

has been prepared and been placed in the docket. As mentioned above,

the agency estimates that the costs attributable to these requirements

are approximately $1.03 million for testing costs.

Based on its analysis, the agency concludes that the requirements

will improve safety by ensuring that all heavy vehicles are capable of

stopping within a safe distance. The agency believes that implementing

the stopping distance requirements for heavy vehicles will not result

in significant costs since the braking performance of currently

produced vehicles is adequate for these vehicles to comply with the

reinstated requirements.

B. Regulatory Flexibility Act

NHTSA has also considered the impacts of this notice under the

Regulatory Flexibility Act. I hereby certify that this proposed rule

will not have a significant economic impact on a substantial number of

small entities. As mentioned above, most heavy vehicles will comply

with the requirements without the need for significant changes. In

addition, the agency is not aware of any manufacturer of heavy vehicles

or hydraulic brake systems that is considered to be a small entity.

There are no added costs associated with modifying a vehicle's brake

system to comply with the requirements implemented by this final rule.

The industry test cost per vehicle to assure compliance with the

proposal is very small: $5.30. Accordingly, no regulatory flexibility

analysis has been prepared.

C. Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1980 (P.L. 96-

511), there are no requirements for information collection associated

with this proposed rule.

D. National Environmental Policy Act

NHTSA has also analyzed this rule under the National Environmental

Policy Act and determined that it will not have a significant impact on

the human environment. No changes in existing production or disposal

processes will result, except that there is a reduction resulting from

the removal of the ALV. Nor should production and disposal processes

have a significant adverse affect on the environment.

E. Executive Order 12612 (Federalism)

NHTSA has analyzed this rule in accordance with the principles and

criteria contained in E.O. 12612, and has determined that this rule

will not have significant federalism implications to warrant the

preparation of a Federalism Assessment.

[[Page 13303]]

F. Civil Justice Reform

This final rule does not have any retroactive effect. Under 49

U.S.C. 30103, whenever a Federal motor vehicle safety standard is in

effect, a State may not adopt or maintain a safety standard applicable

to the same aspect of performance which is not identical to the Federal

standard, except to the extent that the State requirement imposes a

higher level of performance and applies only to vehicles procured for

the State's use. 49 U.S.C. 30161 sets forth a procedure for judicial

review of final rules establishing, amending or revoking Federal motor

vehicle safety standards. That section does not require submission of a

petition for reconsideration or other administrative proceedings before

parties may file suit in court.

List of Subjects in 49 CFR Part 571

Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber

products, Tires.

In consideration of the foregoing, the agency is amending Standard

No. 105, Hydraulic Brake Systems, in Title 49 of the Code of Federal

Regulations at Part 571 as follows:

PART 571--[AMENDED]

1. The authority citation for Part 571 continues to read as

follows:

Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166,

delegation of authority at 49 CFR 1.50.

Sec. 571.105 [Amended]

2. Section 571.105 is amended by adding the definition of ``wheel

lockup'' in S4 and by revising Table II, S5.1.1, S5.1.1.2, S6, S6.9,

and S6.10; and by adding S6.9.1, S6.9.2, S6.10.1 and S6.10.2 to read as

follows:

* * * * *

Wheel lockup means 100 percent wheel slip.

* * * * *

[[Page 13304]]

Table II.--Stopping Distances

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Stopping distance in feet for tests indicated

-----------------------------------------------------------------------------------------------------------------------------------------------

I--1st (preburnished) & 4th II--2d effectiveness III--3d (lightly loaded vehicles) IV--Inoperative brake

effectiveness; spike effectiveness ------------------------------------ effectiveness power and power assist

Vehicle test speed (miles per hour) check --------------------------------------------- unit; partial failure

------------------------------------ (b) & --------------------------

(a) (c) (d) (e) (a) (b) (c) (d) (e) (b) & (d) &

(a) (b) (c) (d) (a) (c) (e)

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

30.............................................. 157 1,265 1,269

(1st)

1,265 (4th

and

spike)

172 1,288 154 157 1,278 70 51 57 65 84 70 114 130 170

35.............................................. 74 83 91 132 70 74 106 96 67 74 83 114 96 155 176 225

40.............................................. 96 108 119 173 91 96 138 124 87 96 108 149 124 202 229 288

45.............................................. 121 137 150 218 115 121 175 158 110 121 137 189 158 257 291 358

50.............................................. 150 169 185 264 142 150 216 195 135 150 169 233 195 317 359 435

55.............................................. 181 204 224 326 172 181 261 236 163 181 204 281 236 383 433 530

60.............................................. 1216 1242 1267 1,2388 1204 1216 1310 280 1194 1216 1242 1335 280 1456 1517 1613

80.............................................. 1405 1459 1510 NA 1383 NA NA NA NA NA NA NA NA NA NA NA

95.............................................. 1607 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

100............................................. 1673 NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1Distance for specified tests. 2Applicable to school buses only. NA=Not applicable.

Note: (a) Passenger cars; (b) vehicles other than passenger cars with GVWR of less than 8,000 lbs; (c) vehicles with GVWR of not less than 8,000 lbs and not more than 10,000 lbs; (d) vehicles

with GVWR greater than 10,000 lbs; (e) buses, including school buses, with GVWR greater than 10,000 lbs.

[[Page 13305]]

* * * * *

S5.1.1 Stopping distance.

(a) The service brakes shall be capable of stopping each vehicle

with a GVWR of less than 8,000 pounds, and each school bus with a GVWR

between 8,000 pounds and 10,000 pounds in four effectiveness tests

within the distances and from the speeds specified in S5.1.1.1,

S5.1.1.2, S5.1.1.3, and S5.1.1.4.

(b) The service brakes shall be capable of stopping each vehicle

with a GVWR of between 8,000 pounds and 10,000 pounds, other than a

school bus, in three effectiveness tests within the distances and from

the speeds specified in S5.1.1.1, S5.1.1.2, and S5.1.1.4.

(c) The service brakes shall be capable of stopping each vehicle

with a GVWR greater than 10,000 pounds in two effectiveness tests

within the distances and from the speeds specified in S5.1.1.2 and

S5.1.1.3.

* * * * *

S5.1.1.2 In the second effectiveness test, each vehicle with a

GVWR of 10,000 pounds or less and each school bus with a GVWR greater

than 10,000 pounds shall be capable of stopping from 30 mph and 60 mph,

and each vehicle with a GVWR greater than 10,000 pounds (other than a

school bus) shall be capable of stopping from 60 mph, within the

corresponding distances specified in Column II of Table II. If the

speed attainable in 2 miles is not less than 84 mph, a passenger car or

other vehicle with a GVWR of 10,000 pounds or less shall also be

capable of stopping from 80 mph within the corresponding distances

specified in Column II of Table II.

* * * * *

S6 Test conditions. The performance requirements of S5 shall be

met under the following conditions. Where a range of conditions is

specified, the vehicle shall be capable of meeting the requirements at

all points within the range. Compliance of vehicles manufactured in two

or more stages may, at the option of the final-stage manufacturer, be

demonstrated to comply with this standard by adherence to the

instructions of the incomplete manufacturer provided with the vehicle

in accordance with Sec. 568.4(a)(7)(ii) and Sec. 568.5 of title 49 of

the Code of Federal Regulations.

* * * * *

S6.9 Road Surface.

S6.9.1 For vehicles with a GVWR of 10,000 pounds or less, road

tests are conducted on a 12-foot-wide, level roadway, having a skid

number of 81. Burnish stops are conducted on any surface. The parking

brake test surface is clean, dry, smooth, Portland cement concrete.

S6.9.2 For vehicles with a GVWR greater than 10,000 pounds, road

tests are conducted on a 12-foot-wide, level roadway, having a peak

friction coefficient of 0.9 when measured using an American Society for

Testing and Materials (ASTM) E 1136 standard reference test tire, in

accordance with ASTM Method E 1337-90, at a speed of 40 mph, without

water delivery. Burnish stops are conducted on any surface. The parking

brake test surface is clean, dry, smooth, Portland cement concrete.

* * * * *

S6.10 Vehicle Position and Wheel Lockup Restrictions. The vehicle

is aligned in the center of the roadway at the start of each brake

application. Stops, other than spike stops, are made without any part

of the vehicle leaving the roadway.

S6.10.1 For vehicles with a GVWR of 10,000 pounds or less, stops

are made with wheel lockup permitted only as follows:

(a) At vehicle speeds above 10 mph, there may be controlled wheel

lockup on an antilock-equipped axle, and lockup of not more than one

wheel per vehicle, uncontrolled by an antilock system. (Dual wheels on

one side of an axle are considered a single wheel.)

(b) At vehicle speeds of 10 mph or less, any wheel may lock up for

any duration.

(c) Unlimited wheel lockup is allowed during spike stops (but not

spike check stops), partial failure stops, and inoperative brake power

or power assist unit stops.

S6.10.2 For vehicles with a GVWR greater than 10,000 pounds, stops

are made with wheel lockup permitted only as follows:

(a) At vehicle speeds above 20 mph, any wheel on a nonsteerable

axle other than the two rearmost nonliftable, nonsteerable axles may

lock up for any duration. The wheels on the two rearmost nonliftable,

nonsteerable axles may lock up according to (b).

(b) At vehicle speeds above 20 mph, one wheel on any axle or two

wheels on any tandem may lock up for any duration.

(c) At vehicle speeds above 20 mph, any wheel not permitted to lock

in (a) or (b) may lock up repeatedly, with each lockup occurring for a

duration of one second or less.

(d) At vehicle speeds of 20 mph or less, any wheel may lock up for

any duration.

(e) Unlimited wheel lockup is allowed during partial failure stops,

and inoperative brake power or power assist stops.

Issued on March 1, 1995.

Ricardo Martinez,

Administrator.

[FR Doc. 95-5412 Filed 3-7-95; 8:45 am]

BILLING CODE 4910-59-P