Consumer Information Regulations; Federal Motor Vehicle Safety Standards; Rollover Prevention

Federal RegisterJun 28, 1994

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 575

[Docket No. 91-68; Notice 03]

RIN 2127-AC64

Consumer Information Regulations; Federal Motor Vehicle Safety

Standards; Rollover Prevention

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Notice of proposed rulemaking (Consumer Information

Regulation); Termination of rulemaking (Federal Motor Vehicle Safety

Standard).

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SUMMARY: As part of its comprehensive efforts to address the problem of

light vehicle rollover, this agency is proposing a new consumer

information regulation that would require that passenger cars and light

multipurpose passenger vehicles and trucks be labeled with information

about their resistance to rollover. This information would enable

prospective purchasers to make choices about new vehicles based on

differences in rollover risk; motivate manufacturers to give more

priority to rollover stability in designing their vehicles; and inform

motorists that they can reduce the risk of injury in a rollover by

wearing their safety belts. NHTSA believes that this would reduce the

number of injuries and fatalities from rollover accidents.

DATES: Comment Date: Comments must be received by August 29, 1994.

ADDRESSES: Comments should refer to the docket and notice number of

this notice and be submitted to: Docket Section, Room 5109, National

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

Washington, DC 20590. (Docket Room hours are 9:30 a.m.-4 p.m., Monday

through Friday.)

FOR FURTHER INFORMATION CONTACT: Gayle Dalrymple, Office of Vehicle

Safety Standards, NRM-11, National Highway Traffic Safety

Administration, 400 Seventh Street, SW., Washington, DC 20590.

Telephone: (202) 366-5559.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. The Rollover Crash Problem

II. Relationship to Other Agency Activities

A. Agency Efforts to Address the Rollover Crash Problem

B. Consumer Information Activities

III. Background

A. Statutory Requirement for Rulemaking

B. ANPRM and the Planning Document

C. Comments on the ANPRM and the Planning Document

IV. Summary

A. Summary of Agency Decision Not to Propose a Vehicle Standard

B. Summary of Proposed Consumer Information Regulation

V. Agency Analysis of the Vehicle Stability Metrics

A. Identification of Vehicle Stability Metrics

B. Analysis of Importance of Factors

1. Additional Analyses since the ANPRM

2. Predictive Power of the Metrics

VI. Decision Not to Propose a Vehicle Stability Standard

A. Estimates of the Benefits of a Standard

1. Rollover Risk Reduction

2. Predicted Single Vehicle Accident Rate

3. Injury/Fatality Rate Reduction

B. Estimates of the Costs of a Standard

C. Conclusions

VII. Proposed Consumer Information Regulation

A. Rationale

B. Proposed Label

C. Stability Metrics

1. Critical Sliding Velocity

2. Tilt Table Angle

D. Timing of Information Provided by the Manufacturers and NHTSA

E. Benefits

F. Costs

VIII. Final Stage Manufacturers and Alterers

IX. Rulemaking Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and

Procedures

B. Regulatory Flexibility Act

C. Paperwork Reduction Act

D. National Environmental Policy Act

E. Executive Order 12612 (Federalism)

F. Civil Justice Reform

X. Effective Date of Final Rule

XI. Submission of Comments

I. The Rollover Crash Problem

Rollover crashes occur for many reasons, and involve the

interaction of a variety of factors including the driver, the roadway,

the vehicle, and environmental conditions. The relationship of these

various factors to rollover crashes can be examined by analyzing data

from various sources.

The agency estimates that there were 220,000 rollover crashes

involving passenger cars, and multipurpose passenger vehicles and

trucks under 4,536 kilograms (10,000 pounds) gross vehicle weight

rating (collectively, ``light trucks'') in 1991. These resulted in

9,186 fatalities; 56,000 occupants of these vehicles received serious,

incapacitating injuries. These numbers have remained relatively

constant over the past six years. Ejections are responsible for 63

percent of the fatalities. Safety belts are used by only 13 percent of

the fatally injured occupants.

Of the 220,000 rollover crashes, 207,000, or 94 percent, were

single vehicle crashes and 192,000 of these, or 93 percent, occurred

off the road. Various accident studies have indicated that loss of

vehicle directional control is a prelude to rollover in 50 percent to

80 percent of all rollover crashes.

For the years 1985-1991, small cars had the greatest number of

rollover fatalities, followed by standard-size pickup trucks. However,

pickup trucks and sport utility vehicles have fatality rates per

million registered vehicles between two and three times as great as

that of passenger cars. The difference between the numbers of rollover

fatalities and the rollover fatality rates for particular vehicle types

is a result of the relative proportions of various types of vehicles in

the fleet. There are currently many more small cars than pickup trucks

and sport utility vehicles on the road today.

(A more extensive discussion of rollover statistics, and the

sources for this information, can be found in the ``Addendum to

Technical Assessment Paper,'' NHTSA 1994, which is in Docket No. 91-68,

Notice 03.)

II. Relationship to Other Agency Activities

A. Agency Efforts To Address the Rollover Crash Problem

The agency believes that no single type of rulemaking or other

agency action could solve all, or even a majority of, the problems

associated with rollover. Accordingly, it is pursuing a broad range of

actions to address those problems.

First, NHTSA has published an NPRM to reduce the potential for

injuries to the head from contact with upper interior components (58 FR

7506, February 8, 1993). The comment period was reopened to December 1,

1993 (58 FR 54099, October 20, 1993) and a public hearing was held on

November 15, 1993. As explained in the Addendum to Technical Assessment

Paper, NHTSA's research indicates that head injuries are the most

prevalent type of injury associated with rollovers. The agency expects

to issue a final rule on this subject in late 1994.

Second, with respect to anti-lock brake systems, the agency has

published an advance notice of proposed rulemaking (ANPRM) for light

duty vehicles (January 4, 1994, 59 FR 281). (``Light duty vehicles''

include cars, vans, pickup trucks and sport utility vehicles with a

gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or

less.) Since most vehicles involved in rollovers lose their

longitudinal stability before leaving the roadway, where they then trip

and roll over, and since anti-lock brake systems are designed to

enhance the longitudinal stability of a vehicle, a requirement for

anti- lock brakes could reduce the number of rollovers. NHTSA's

preliminary evaluation of rear-wheel anti-lock brake systems, the type

of anti-lock brakes most often found on light trucks, indicates that

anti-lock brakes on light trucks are effective in reducing the number

of nonfatal single vehicle accident rollovers for almost every type of

truck, under any type of road condition. Reductions of single vehicle

accident rollovers were typically in the range of 30 percent to 40

percent. NHTSA is continuing to analyze the data and a comprehensive

report of the findings will be published at a later date. (The

preliminary evaluation is available in Docket No. 70-27-GR-026.)

Third, as noted above, ejections are a frequent occurrence in fatal

rollover crashes. To attempt to reduce the frequency of ejections, the

agency is conducting research on glass/plastic side windows and

improved door latches. Preliminary research results should be available

within the next year to enable NHTSA to determine if rulemaking should

be pursued in these areas.

Fourth, the agency is conducting research on improvements to

vehicles' roof strength that could reduce head and neck injuries. A

decision whether to begin rulemaking on this subject is expected in

1994.

Fifth, as noted above, safety belt use is very low among persons

fatally or seriously injured in rollover crashes. NHTSA promotes

increased use of safety belts through public awareness and education

efforts and by supporting the implementation and enforcement of state

safety belt use laws. Agency occupant protection awareness and

education activities include national media campaigns; outreach through

national health, medical, civic, and intergovernmental organizations;

and, administration of Section 402 state highway safety program funds.

The agency promotes effective state safety belt usage laws by

conducting evaluation studies and demonstration projects, training law

enforcement personnel, and by administering the Section 153 state

incentive grant program.

In addition, NHTSA has contracted with the Advertising Council to

prepare two ``Vince and LarrySM'' (the agency's safety belt

``spokespersons'') public service announcements (PSAs) for television,

and one ``Vince and LarrySM'' PSA for radio, on the specific

benefits of safety belts in rollover crashes. One of the television

PSAs and the radio PSA were available at the end of March, 1994. The

other television PSA will be available approximately six months later.

These safety belt initiatives will supplement the other actions to

address the rollover problem.

Sixth, it is well known that rollover crashes have a high incidence

of alcohol involvement. The agency has numerous programs and activities

aimed at reducing alcohol-related crashes, injuries, and fatalities,

which follow two fundamental strategies: information-education (such as

Advertising Council PSAs on television) and laws-enforcement-sanctions

(such as .08 BAC, sobriety checkpoints, and increasingly severe

sanctions for repeat offenders). Section 410 grants to states provide

incentives to states to use these strategies. These combined strategies

have been effective as alcohol-related fatalities have decreased 30

percent over the past 10 years.

Seventh, and finally, the agency is issuing this notice regarding

vehicle stability requirements and consumer information.

B. Consumer Information Activities

NHTSA believes that consumer and manufacturer behavior can be

affected through the provision of consumer information regarding

vehicle safety. The agency's experience with the New Car Assessment

Program (NCAP) demonstrates the power of consumer information. Under

the NCAP Program, the agency tests the ability of vehicles to protect

their front seat occupants in frontal crash tests. The tests are

similar to those conducted under Standard No. 208, Occupant Protection,

to determine whether vehicles meet the Standard's injury criteria,

except that the Standard's tests are conducted at 30 mph, while NCAP

tests are conducted at 35 mph. Several manufacturers have informed the

agency that they view it as important to perform well in the NCAP

tests, even though there is no regulatory requirement to do so. The

decline in the injury scores in NCAP tests over time for all

manufacturers, as reported in ``Report on the Historical Performance of

Different Auto Manufacturers in the New Car Assessment Program Tests,''

NHTSA, August 1993, can also be attributed partially to NCAP.

The agency believes that further safety improvements could be

gained through providing consumers with information about additional

aspects of new vehicle safety performance. NHTSA recently conducted a

series of 15 focus groups, comprised of members of the public, to

examine the type and format of desired consumer information about

vehicle safety. (See ``Focus Groups on Traffic Safety Issues: Public

Response to NCAP,'' S.W. Morris & Company, Inc., August 1993, which can

be found in Docket No. 79-17, Notice 01, or ``New Car Assessment

Program--Response to the NCAP FY 1992 Congressional Requirements,''

Report to the Congress, December 1993, which can be found in Docket No.

97-17, Notice 39). One of the topics examined was the current NCAP and

how it could be improved. In response to the results of the focus group

work, the agency has changed the format for NCAP test results. The new

format responds to consumer demand for reporting results in a way that

is less technical and easier to understand.

The focus groups also indicated that the agency's consumer safety

information activities should be expanded to include additional kinds

of crashes, including side impacts and rollovers. The potential

importance of providing broader safety information about new light duty

vehicle performance can be seen from figures regarding the proportion

of fatalities in each of the three most important types of crashes. In

1991, frontal crashes accounted for 39 percent of all fatalities

involving light duty vehicle occupants, rollover crashes for 30

percent, and side impact crashes for 25 percent. Together, these three

types of crashes account for 94 percent of all fatalities. Information

on performance in all three types of crashes could provide consumers

with a comprehensive, balanced picture of the safety of new vehicles.

As part of its efforts to expand its consumer safety information

programs, NHTSA has sought participation and guidance from the general

public on the types and format of safety information to be provided to

consumers. On January 3, 1994, the agency published a request for

comments on whether to supplement the agency's efforts by holding a

public meeting to discuss, among other items, the expansion of the NCAP

program to other crash modes (59 FR 104).

Based on the foregoing, the agency plans to supplement this

rollover proposal with a future proposal for requiring that each new

vehicle have a window sticker providing information not only on vehicle

rollover resistance, but also on frontal and side impact crash

performance.

III. Background

A. Statutory Requirement for Rulemaking

The NHTSA Authorization Act of 1991 (the Act) (part of the

Intermodel Surface Transportation Efficiency Act) requires the agency

to address several vehicle safety subjects through rulemaking. One of

the subjects, set forth in section 2503(1), is protection against

unreasonable risk of rollovers of passenger cars, multipurpose

passenger vehicles, and trucks with a gross vehicle weight rating of

8,500 pounds or less and an unloaded vehicle weight of 5,500 pounds or

less.

Section 2502(b)(2)(A) of the Act required that NHTSA publish, no

later than May 31, 1992, an ANPRM or a notice of proposed rulemaking

(NPRM) on this subject. The January 3, 1992, ANPRM fulfilled this

mandate.

Section 2502(b)(2)(B)(i) of the Act provides that the agency must

complete a rulemaking action on rollover within 26 months of publishing

the ANPRM. The ANPRM was published on January 3, 1992; thus, this

rulemaking action was to have been completed by March 3, 1994. Section

2502(b)(2)(B)(ii) of the Act provides that this rulemaking will be

considered completed when NHTSA either publishes a final rule or

decides and announces that it is not promulgating a rule.

B. ANPRM and Planning Document

NHTSA announced in its January 3, 1992 ANPRM on the rollover

problem that it was considering various regulatory actions to reduce

the frequency of vehicle rollovers and/or the number and severity of

injuries resulting from vehicle rollovers (57 FR 242). The agency

requested comments on potential regulatory actions in the areas of: (1)

Improved stability; (2) improved crashworthiness; and (3) consumer

information. NHTSA said that it might issue a rule or rules in any one

of these three categories, or in any combination of them.

The ANPRM discussed the agency's statistical analyses of the

interaction of driver characteristics, vehicle stability metrics,

roadway and environmental conditions. The notice described the

following vehicle stability metrics as having a potentially significant

role in vehicle rollover: center of gravity height; static stability

factor; tilt table ratio; side pull ratio; wheelbase; critical sliding

velocity; rollover prevention metric; braking stability metric; and

percent of total vehicle weight on the rear axle. A vehicle stability

metric is a measured vehicle parameter that presumably is related to

the vehicle's likelihood of rollover involvement. To supplement the

ANPRM, a Technical Assessment Paper that discussed testing activities,

testing results, accident data collection, and analysis of the data was

placed in the docket on January 6, 1992. A description of the

individual metrics can be found in the Technical Assessment Paper.

(Note: For the remainder of this notice, ``tilt table angle'' is

used in place of ``tilt table ratio,'' regardless of the term used

in any other document. NHTSA is using ``tilt table angle'' because

the agency is proposing tilt table angle as one of the possible

measurements to be used in the proposed consumer information

regulation. Tilt table angle is the angle at which the last uphill

tire of a vehicle lifts off a tilting platform. Tilt table ratio is

the tangent of the tilt table angle and is believed to be harder for

the average consumer to understand.)

During the development of the ANPRM and subsequent to receiving and

analyzing comments to the ANPRM, it became obvious that no single type

of rulemaking could solve all, or even a majority of, the problems

associated with rollover. This view was strengthened by the agency's

review and analysis of the comments on the ANPRM. To emphasize this

conclusion and inform the public further about the complicated nature

of the light duty vehicle rollover problem, the agency released a

document titled ``Planning Document for Rollover Prevention and Injury

Mitigation'' at a Society of Automotive Engineers meeting on rollover

on September 23, 1992. The Planning Document gave an overview of the

rollover problem and a list of alternative actions that NHTSA was

examining to address the problem. Alternatives for regulatory action

and a schedule for decisions on each were included. The current status

of the presented alternative actions was discussed earlier in this

notice. The document was placed in Docket No. 91-68; Notice 02, on the

same day. NHTSA published a notice in the Federal Register announcing

the availability of the Planning Document and requesting comment

(September 29, 1992; 57 FR 44721).

C. Comments on the ANPRM and the Planning Document

Forty-two comments concerning the ANPRM and the Planning Document

were received. A Summary of Comments was placed in the docket on

September 15, 1993. Ten commenters addressed the Planning Document,

eight of whom had also commented on the ANPRM. Responses to the

Planning Document, for the most part, were abridged forms of the

commenters' responses to the ANPRM.

All the commenting vehicle manufacturers asserted that, while

stability metrics are statistically related to the rates with which

single vehicle accidents result in rollovers, they are not causally

related to rollover. Therefore, the manufacturers asserted, the agency

cannot issue a regulation based on any one of these metrics solely

because of its statistical correlation with accident data. Automotive

Testing, BMW, Ford, GM, the American Automobile Manufacturers

Association (AAMA, then known as the Motor Vehicle Manufacturers

Association), and VW claimed that stability metrics are insufficient by

themselves to explain a vehicle's degree of involvement in rollover

crashes. These commenters stated that driver and environmental factors

outweigh the contributions of vehicle factors to the likelihood of a

single vehicle accident becoming a rollover. Nevertheless, most

commenters addressed the relevancy of several of the individual metrics

the agency considered for a vehicle stability rulemaking.

Tilt table angle, one of the metrics being proposed in this notice,

appeared to be more acceptable to the commenters than the other

stability metrics. While side pull ratio was favored by Automotive

Testing, Chrysler, GM, and Nissan, all these commenters also commented

favorably on aspects of tilt table angle. Static stability factor was

favored by only Perrone Forensic Consulting, who also commented

favorably on tilt table angle. All other commenters who indicated a

preference among the metrics discussed in the ANPRM favored tilt table

angle. However, Chrysler, Ford, GM, Isuzu, and VW claim vehicle changes

made to improve a vehicle's tilt table performance may degrade a

vehicle's control and handling attributes. Chrysler said that the

repeatability of results from the tilt table procedure was unknown. On

the other hand, Advocates for Highway and Auto Safety, the

International Organization of Motor Vehicle Manufacturers, and GM

stated they believe that the procedure is repeatable. Chrysler and AAMA

also commented that the tilt table test is not a standard practice and

its measurement error has not been established.

Commenters did not respond directly to the idea of using critical

sliding velocity, which is also being proposed for use in this notice.

However, most manufacturers commented that center of gravity height (a

measurement necessary to calculate critical sliding velocity) is

difficult to measure and that the measurement is not repeatable.

Therefore, according to these commenters, any metric which uses center

of gravity height would be impracticable.

The commenters also focussed on crashworthiness improvements. By

far the most favorable crashworthiness countermeasure cited by the

commenters was increased seat belt use to prevent ejections. In

general, commenters believe that more benefits could be gained through

increased seat belt use than through any vehicle related

crashworthiness or crash avoidance countermeasure. Some commenters also

favored improved roof structures including roll bars or cages, but

Ford, GM, Nissan, and VW believe the installation of a roll bar or cage

raises the vehicle's center of gravity and decreases rollover

stability. Other suggestions were for improved glazing, improved latch/

lock/hinge systems for doors, anti-lock brakes, bumper height

regulations, removal of drunk and otherwise impaired drivers from the

road, stricter enforcement of speed limits, and improved public

awareness of the causes of rollover crashes as ways to reduce rollover

casualties.

Finally, Chrysler, GM, AAMA, and Toyota claimed that labeling

vehicles with a stability metric would be simplistic and could mislead

consumers, giving them a false sense of security in a vehicle labeled

with a high stability metric (i.e., a metric indicating comparatively

high resistance to rollover). These commenters believe that consumers

could consider the metric to be an absolute measure of rollover

likelihood, regardless of driver behavior or roadway conditions.

IV. Summary

A. Summary of Agency Decision Not To Propose a Vehicle Standard

In analyzing whether to proceed with a vehicle stability

rulemaking, the agency identified several criteria that had to be met

before proposing a safety standard. First, the identified vehicle

metrics had to have a causal relationship to the likelihood of

rollover. For example, center of gravity height affects rollover

likelihood; the color of the vehicle does not. Second, the metric had

to have a statistical relationship to rollover frequency. Third,

improvement in the metric should result in significant safety benefits

at a reasonable cost without having the effect of necessitating the

radical redesigning of one or more types of vehicles. As discussed

below, the agency identified two metrics that met the first two

criteria, but not the third.

To determine whether it was appropriate to propose a new vehicle

safety standard, NHTSA examined the complex interactions between driver

behavior, vehicle properties, and roadway characteristics which result

in rollovers. The suitability of a vehicle safety standard based on

rollover stability depends on the importance of rollover stability, as

represented by a vehicle metric, relative to other rollover influences,

such as vehicle handling properties, vehicle condition, the nature of

the roadway and shoulder terrain, and driver behavior. The agency

sought to determine whether vehicle stability metrics are significant

variables in a statistical model of the risk of rollover. If they are,

then a standard regulating stability might be justified, depending on

the results of a comparison of benefits and costs for such a standard.

After analyzing a number of static and dynamic rollover metrics,

the agency concluded that two vehicle metrics, tilt table angle and

critical sliding velocity, can account for about 50 percent of the

variability in rollover risk in single vehicle accidents, after

considering driver, roadway, and environmental factors. (Rollover risk

is the number of single vehicle rollovers involving a particular make/

model divided by the number of single vehicle crashes of all types

involving the same make/model.) This statistical analysis was conducted

on all light duty vehicles treated as a group. However, analysis of

accident data indicated that certain subgroups of light duty vehicles

are more likely to roll over than other subgroups. For example, sport

utility vehicles and compact pickup trucks tend to be the most likely

vehicles to roll over. Large passenger cars tend to be the least likely

to roll over. The importance of this difference is that if significant

benefits are to be achieved, then changes in the metric should be made

that affect passenger cars since nearly 60 percent of rollover

fatalities occur in those vehicles.

The agency's analysis showed that setting a performance level high

enough to affect passenger cars, would require redesign of nearly all

sport utility vehicles, vans, and pickup trucks. Using a single value

of one of these metrics as the performance standard for all light duty

vehicles would have resulted in the radical redesign of the

characteristics many, and in some cases all, vehicles of certain

classes. That degree of redesign would have raised issues of public

acceptance and possibly even the elimination of certain classes of

vehicles as they are known today.

To avoid this consequence, the agency then examined whether several

values for these metrics, each applying to a different class of

vehicles (e.g., one value for passenger cars and a different value for

light trucks) would be feasible. Since the statistical analyses

discussed above were conducted on all light duty vehicles treated as a

group, it was necessary to determine whether either of the stability

metrics exhibited sufficiently high levels of correlation to assure the

agency that a requirement applying to only one class of vehicle would

be expected to reduce the incidence of rollovers for vehicles in that

class. As explained later in this notice, the agency found that the

statistical correlations of the metrics with rollover accident data

within a class of vehicles was not so consistent as for all vehicles

grouped together. This weakening of the predictive ability of the

metric is, to some extent, the result of the smaller range of the

metric within any class of vehicles together with the inherent

variability in the data. Based on this analysis, and the general

analysis of costs and benefits discussed later, the agency determined

that proposing a standard specifying one minimum stability value for

cars and others for various classes of light trucks could not be

justified.

The agency also determined that, considering the costs and benefits

involved, proposing a safety standard specifying a single minimum

stability value for both cars and light trucks could not be justified.

While light trucks have lower stability measurements than cars do, the

greatest number of rollover-related deaths and injuries occur in

passenger cars because of their larger population size. Therefore, if

the agency wished to set a stability minimum high enough to realize

significant reductions in the number of fatalities in all light duty

vehicles, it would have to set the minimum above the stability number

of most light trucks. The costs of such a standard, in terms of the

cost of vehicle redesign and the loss of consumer-desired attributes,

were determined to be very high, as entire classes of light trucks

would probably need to be substantially redesigned to meet such a

standard. This redesign could result in the elimination of some vehicle

types, e.g., sport utility vehicles, as they are known today.

Based on this analysis, NHTSA has decided not to propose a vehicle

stability rule, and is deferring any further action on this subject

until such time as information becomes available demonstrating the cost

effectiveness of such a rule. The agency may reinitiate such a

rulemaking upon receipt of such information. This termination of

rulemaking on vehicle stability fulfills the statutory mandate of

section 2502(b)(2)(B)(i). However, through the consumer information

proposal being published today, and the other actions mentioned above,

NHTSA is continuing to take a comprehensive approach to reducing

rollover casualties.

B. Summary of Proposed Consumer Information Regulation

While NHTSA is terminating rulemaking on a vehicle stability

standard, NHTSA believes that the correlation between stability and

rollover risk is significant enough to justify proposing a consumer

information regulation to relieve the possibility of uninformed risk.

The agency believes that informing consumers of the relative resistance

of different vehicles to rollover will influence consumers to purchase

more stable vehicles and encourage manufacturers to improve the

stability of their vehicles. The agency believes that these results are

possible based on its assessment of how consumers and manufacturers

reacted to the provision of frontal crashworthiness information through

the New Car Assessment Program.

The consumer information regulation being proposed by the agency

would require manufacturers of passenger cars and light trucks to label

their vehicles with information relating to rollover stability. To that

end, manufacturers would be required to report a stability metric for

each vehicle make/model to NHTSA by January 1 of each year.

Manufacturers would decide how to group vehicle make/models for the

purpose of reporting stability metrics for those groups. To ensure that

the information is neither understated nor overstated, the reported

stability metric would be measured with a specified procedure and an

accuracy tolerance on reported data would be required. NHTSA would use

the information reported by manufacturers to provide the manufacturers

with the ranges of metrics for both passenger cars and light trucks by

April 1 of each year. For comparison purposes, these ranges would be

included on vehicle labels.

New vehicles manufactured after September 1, 1996 would be required

to have a prescribed window label listing the metric of the labeled

vehicle, the range of that metric for cars and the range for light

trucks. In addition, prescribed language on the label would explain the

significance of the metric, warn consumers that all vehicles can and do

roll over, and remind consumers to always wear seat belts. The proposed

regulation would also require manufacturers to include the information

on the vehicle label in the vehicle's owner's manual.

The agency requests comment on whether or not the proposed vehicle

label should be a permanent sticker, in addition to the window label

which would be removed after first sale. If a commenter believes the

label should be permanent, NHTSA requests comment on whether the

permanent sticker should be required on all vehicles, or only some

subset of vehicles with lower rollover stability. Finally, NHTSA

requests suggestions on placement and size of a permanent sticker. A

permanent sticker would be useful to purchasers of used vehicles and

drivers of rental vehicles.

NHTSA is considering two metrics for providing information

regarding rollover stability: critical sliding velocity and tilt table

angle. Critical sliding velocity is a measure of the minimum lateral

(sideways) vehicle velocity required to initiate rollover when the

vehicle is tripped by something in the roadway environment, e.g., a

curb. Tilt table angle is the angle at which the last uphill tire of

the vehicle lifts off a platform as the platform is increasingly

tilted.

NHTSA is proposing two different options for specifying stability

information using these metrics. First, NHTSA may select one of the two

metrics to appear on the label. For example, if the agency selected

tilt table angle, it would require that the specific angle for each

vehicle be shown on its label. Second, NHTSA may require the label to

include a nonquantitative statement concerning the vehicle's rollover

resistance based on one or both of the metrics. For example, instead of

stating a specific angle, the label might use symbols such as one, two,

or three stars.

V. Agency Analysis of the Vehicle Stability Metrics

A. Identification of Vehicle Stability Metrics

The agency has concluded that the two metrics with the best

correlation to accident statistics are tilt table angle, a static

measurement, and critical sliding velocity, a metric calculated from

static and dynamic vehicle measurements and expressed as velocity,

i.e., units of feet per second, miles per hour, or kilometers per hour.

Tilt table angle includes the influences of the vehicle's mass,

center of gravity height, track width, and suspension movement, all of

which are physically related to rollover stability. Because it does not

require an independent measurement of center of gravity height, it is

more practicable, less costly, and more repeatable than most static

rollover metrics.

Critical sliding velocity includes the roll moment of inertia as

well as the various static factors mentioned above in its calculation.

The Technical Assessment Paper found critical sliding velocity alone to

have less correlation with rollover accident statistics than tilt table

angle, but found it to be a statistically significant addition to a

model already containing tilt table angle. However, an error in the

computation of critical sliding velocity was made in the Technical

Assessment Paper. When the logistic regression was repeated with the

correct critical sliding velocity values and data for more vehicle

make/models and additional accident years, NHTSA found the correlation

of critical sliding velocity to accident statistics for all light duty

vehicles grouped together and for the light truck and passenger car

categories to be better than that for tilt table angle. The Addendum to

Technical Assessment Paper contains the corrected analysis.

B. Analysis of Importance of Factors

1. Additional Analyses Since the ANPRM

Since the ANPRM, new vehicles have been added to the data base and

their metrics measured. Several make/models have been tested in

different configurations to determine the range of metrics within a

make/model, given the different available original equipment options.

Also included are several make/models of trucks and vans with anti-lock

brakes as standard equipment and several make/models of high sales

volume passenger cars equipped with anti-lock brakes. A complete list

of all vehicles measured to date, their tilt table angles and critical

sliding velocities, and the ratio of the number of rollovers involving

a particular vehicle model to the number of single vehicle accidents

involving the same model (RO/SVA) in Michigan from 1986 through 1990

can be found in Docket 91-68, Notice 2.

2. Predictive Power of the Metrics

The agency performed two types of analyses attempting to separate

the influence of driver characteristics, road, and environmental

variables in the accident data so that the effect of vehicle rollover

stability could be isolated. A logistic regression analysis

individually considered every accident in a very large data base. Make/

models represented in a great number of accidents influenced the

results more than make/models with fewer accidents. A linear regression

analysis was also done on the rollover risk of make/models, adjusted

for differences in driver and road characteristics within their

individual accident data bases, but not weighted by differences in

accident numbers. The two analyses are discussed in detail in the

Addendum to Technical Assessment Paper.

These analyses were conducted using three statistical models: (a) A

model containing only driver, roadway, and environmental

characteristics; (b) a model containing driver, roadway, and

environmental characteristics, and critical sliding velocity; and (c) a

model containing driver, roadway, and environmental characteristics,

and tilt table angle. For the purposes of comparison, the analyses were

limited to accidents involving those make/models for which the agency

had both tilt table angle and critical sliding velocity data. This

results in an equal number of accidents, or observations (88,397), in

each statistical model.

The logistic regression predicts whether a single vehicle accident

will be a rollover based on the factors in a particular model. Then the

predicted outcomes of the individual accidents are compiled to predict

a rollover risk (rollovers per single vehicle accident) for each of the

128 make/models for which the agency has data on both metrics. This

predicted risk is then compared to the actual risk known from accident

data on these make/models. Two numbers are presented in the table below

for each of the statistical models. The first is the percent

variability explained by the comparison of the rollover risk predicted

by the logistic regression model and the actual rollover risk. The

second number is the percentage of the variability unexplained by the

model containing only driver, roadway, and environmental

characteristics which is explained by the addition of either tilt table

angle or critical sliding velocity. For example, the driver/road/

environmental model leaves 77 percent of the variability in the data

unexplained; 23 percent is explained. When tilt table angle was added

to the model to represent vehicle stability, 65 percent of the

variability in rollover risk was explained. The difference between the

77 percent unexplained variability in the driver/road variable model

and the 35 percent unexplained variability of the driver/road variable

plus tilt table angle model is 42 percent, which is 55 percent of the

unexplained variability in the driver/road variable model (42 percent/

77 percent). Slightly more than half of the variability unaccounted for

by driver and road characteristics was explained by the addition of

tilt table angle. Thus, the logistic regression analysis indicates that

stability, as measured by tilt table angle, is an important predictor

of the likelihood of a single vehicle accident becoming a rollover.

Substitution of critical sliding velocity produced similar results. A

complete discussion of the results of these analyses can be found in

the Addendum to Technical Assessment Paper in the docket.

Table 1.--Results of Logistic Regression Analysis for All Vehicles for

Which Tilt Table Angle (TTA) and Critical Sliding Velocity (CSV) Are

Known

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

Percent

variability

Percent explained,

Model variability which is not

explained explained by D/

R/E only model

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

D/R/E only.............................. 23 NA

D/R/E & TTA............................. 65 55

D/R/E & CSV............................. 75 68

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

The linear regression analysis also demonstrates the predictive

power of tilt table angle and critical sliding velocity. This analysis

showed that tilt table angle accounts for about 53 percent of the

variability in rollover risk remaining after adjustment for differences

in driver and road characteristics. The analysis showed that critical

sliding velocity accounts for about 66 percent of the variability in

rollover risk remaining after adjustments for driver and road

characteristics. These compare to the 55 percent and 68 percent values

found by logistic regression. These figures demonstrate that the two

analytic methods are essentially in agreement regarding the statistical

significance of stability metrics to the prediction of rollover.

The results of both the logistic and linear regression analyses

performed by the agency suggest that a vehicle stability metric alone

can account for approximately 50 percent of the variability in rollover

risk in single vehicle accidents, for the population of make/models

studied. While ideally it would be desirable to have these variables

explain 100 percent of the remaining variability, such statistical

correlations are almost never achieved. The agency views these analyses

as demonstrating sound statistical and causal relationships between

these variables and the likelihood of rollover. At the same time, the

analyses show that other factors in addition to those analyzed are

affecting rollover risk, as 35 percent to 25 percent of the variability

in rollover risk is still unexplained after accounting for the driver,

roadway, and tilt table angle or critical sliding velocity,

respectively.

The above analyses used a Michigan accident data base combining

passenger cars, pickup trucks, vans, and sport utility vehicles. As

explained in section I, the rate of rollover fatalities and injuries

per million registered vehicles is higher for sport utility vehicles

and compact pickup trucks, but the absolute majority of harm occurs in

passenger cars, because of their large numbers in use. In the current

vehicle fleet, passenger cars generally have higher measured stability

than light trucks. Thus, a safety standard requiring a minimum level of

stability appropriate for all light duty vehicles would not be expected

to affect many present or future small cars and therefore would not

result in significant safety benefits. (For a further discussion of the

problems associated with a minimum standard, see the section below

entitled, ``Estimate of the Costs of a Standard.'')

Hence, the agency also examined the relative predictive capability

of the stability metrics to rollover risk for passenger cars and light

trucks separately, to investigate the possibility of setting a higher

minimum level of stability for passenger cars. The results are shown in

the table below, including a comparison to the results for all vehicles

considered as a single group (see Table 1). As with the analysis of all

vehicles considered as a single group, these analyses were limited to

make/models for which both tilt table angle and critical sliding

velocity were known.

Table 2.--Results of Logistic Regression Analysis for Vehicles by Class

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

TTA as metric CSV as metric

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

Percent variability Percent variability

Vehicle class ---------------------- Percent ---------------------- Percent

D/R/E explain D/R/E explain

only + metric only + metric

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

All vehicle................................... 23 65 55 23 75 68

Lt. Truck only................................ 21 52 39 21 70 62

Car only...................................... 39 56 28 39 63 39

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

These results show that, while a good proportion of the variability

remaining in the driver/road/environmental model is explained by either

metric for the group containing all vehicles, when the vehicles are

divided into classes, the results are not consistent. The inconsistency

seen in the model results by vehicle class is, to some extent, the

result of the smaller range of the metric within any subgroup of

vehicles together with the inherent variability in the data. These

analyses and the analyses of benefits and costs discussed later,

indicate that different minimum standards for passenger cars and light

trucks cannot be supported using either tilt table angle or critical

sliding velocity.

VI. Decision Not To Propose a Vehicle Stability Standard

As discussed previously, NHTSA concluded that both of the vehicle

metrics, tilt table angle and critical sliding velocity, were

statistically and causally related to the likelihood of rollover in a

single vehicle crash. To determine whether to propose a vehicle

stability standard, NHTSA next compared the benefits and costs of such

a standard. A detailed discussion of the benefits analysis can be found

in ``Potential Reductions in Fatalities and Injuries in Single Vehicle

Rollover Crashes as a Result of a Minimum Rollover Stability

Standard,'' which has been placed in Docket No. 91-68, Notice 03. A

detailed discussion of the cost estimates can be found in the

Preliminary Regulatory Evaluation, which has also been placed in Docket

No. 91-68, Notice 03.

A. Estimate of the Benefits of a Standard

The agency made two basic estimates of benefits of a minimum

standard for rollover stability. One was based on the reductions in RO/

SVA predicted by the logistic regression model for increases in

critical sliding velocity. The other was based on reductions in RO/SVA

predicted for increases in tilt table angle. All other factors being

equal, it is reasonable to expect an inverse relationship between

rollover risk and either critical sliding velocity or tilt table angle.

Thus, the higher the lateral sliding velocity necessary to trip a

vehicle, the less likely it is to roll over, and vice versa. Similarly,

the greater the angle necessary to tip a vehicle from the tilt table,

the less likely it is to roll over, and vice versa.

To quantify the benefits of potential minimum standards for

rollover stability, NHTSA examined the net prevention of fatalities and

serious injuries associated with various minimum levels of critical

sliding velocity and tilt table angle. Fatality and injury levels were

estimated by using:

1. The reduction of the rollover risk predicted for increases in

critical sliding velocity or tilt table angle;

2. The number of single vehicle accidents per registered vehicle

expected to occur; and

3. The reduction in fatalities and/or injuries if a single vehicle

accident does not result in a rollover.

The estimate of the benefits of a minimum stability safety standard

incorporated several simplifying assumptions. First, the agency assumed

that the severity of the accidents would be reduced but that the

accidents would not be prevented. Because single vehicle rollover

accidents are more severe than single vehicle non-rollover accidents,

prevention of rollover reduces the number of serious injuries and

fatalities. However, under this scenario, the total number of single

vehicle accidents is assumed to remain constant. This assumption is

somewhat pessimistic, because an unknown number of crashes would most

likely be avoided. But the remaining assumptions used may tend to

overestimate the benefits since NHTSA also assumed:

1. The numbers of rollover injuries and fatalities prevented would

be proportional to the number of rollovers prevented, and

2. The fatality and injury rates of the late 1980s for the make/

models which would be affected by a minimum standard will remain

representative in the future.

The second assumption may overstate the benefits if increased

safety belt use in the 1990s, as is the goal of NHTSA, reduces the

overall harm from rollover accidents. That is, as belt use increases,

rollover casualties decrease, even though the number of rollover

crashes remains constant.

1. Rollover Risk Reduction

To estimate the reduction in the rollover risk that would be

obtained by changing a vehicle metric, the agency used logistic

regression to determine the sensitivity of rollover risk to changes in

critical sliding velocity or tilt table angle. The outcome of each

accident of the subject make/model in the data base was re-evaluated

individually changing the stability metric but retaining the other

vehicle, driver, and road characteristics present in the actual crash.

A new RO/SVA ratio was determined on the basis of the predicted outcome

of each accident.

To examine the sensitivity of the model to a change in critical

sliding velocity, the agency divided the range of critical sliding

velocities from 14.26 to 16.73 kilometers per hour (kph). The low end

of this range is representative of vehicles in NHTSA's database with

the lowest critical sliding velocity. The high end of this range is

representative of a critical sliding velocity equivalent to the 1.20

value for static stability factor recommended in the Wirth petition

(also equivalent to a tilt table angle of 46.4 degrees). (A discussion

of the Wirth petition can be found in the ANPRM, 57 FR 242, 244-45.)

The highest value in the range is greater than the proposed European

tilt table angle limit of 44.3 degrees, and in the agency's judgement

represents the highest practicable standard. A standard at the upper

limit of the range would affect 1,648,000 vehicles manufactured in

1991, including 87 percent of compact sport utility vehicles, 100

percent of standard vans, and 31 percent of compact pickups.

The agency then divided this range into six even increments and

calculated the RO/SVA for each increment for various classes of

vehicles. Each successively higher increment represents an increase in

critical sliding velocity of 0.41 kph. The agency then predicted the

decrease in single vehicle accident rollovers for each incremental

increase in critical sliding velocity. (See Table 3.)

Table 3.--Sensitivity of RO/SVA to Changes in CSV in kph Simulated by Logistic Regression Model for Vehicles of

CSV TP28JN94.000

where,

TP28JN94.001

and

Ixx = roll mass moment of inertia of the vehicle, in kilogram-

kilometers\2\

g = gravitational constant, in kilometers/hour\2\

M = mass of the vehicle, loaded, in kilograms

hcg = center of gravity height of the vehicle, in kilometers

TW = the average of the front and rear track width of the vehicle, in

kilometers.

Calculation of critical sliding velocity requires knowledge of the

vehicle's mass, track width, center of gravity height, and roll moment

of inertia. NHTSA agrees with commenters that the center of gravity

height and roll moment of inertia are complicated measurements. To

address comments on the repeatability of center of gravity height

measurement, NHTSA reviewed two reports.

The study ``Center of Gravity Height: A Round-Robin Measurement

Program,'' sponsored by the Motor Vehicle Manufacturers Association and

conducted by the University of Michigan Transportation Research

Institute (UMTRI-91-4) compared the test facilities, procedures, and

results of center of gravity height measurements at four laboratories.

Each of the four laboratories used different test equipment and

procedures. The study concluded that different measurement procedures

can produce significantly different results. However, the study also

concluded that for each laboratory and test procedure, repeatability

was very good.

Another study, ``Vehicle Inertial Parameters--Measured Values and

Approximations,'' by Garrott et al. (Society of Automotive Engineers

#881767) shows the coefficient of variation of center of gravity height

at the Vehicle Research and Test Center (VRTC) facility to be 0.8

percent. The measurements used in the analyses of the relationship of

critical sliding velocity and single vehicle rollover accidents came

from the VRTC facility.

Based on these studies, NHTSA believes that measurements of center

of gravity height and roll moment of inertia are repeatable within an

individual laboratory using a specified procedure. NHTSA also believes

that these measurements would be repeatable among different

laboratories if all were using the same test procedure. The agency has

data on a group of six make/models of light trucks and one make/model

of car for which tests were run on identical vehicles, or repeated

tests were run on the same vehicle. The results for all of these tests

show the repeatability of critical sliding velocity to be well within

the required accuracy of one kilometer per hour. Therefore, NHTSA

tentatively concludes that the test procedure proposed in this notice

would produce repeatable results. The proposed regulatory text does not

include language for either the test equipment or the test procedure.

The test equipment to be used in the procedure is VTRC's Inertial

Parameter Measuring Device (IPMD). The equipment is described in United

States Patent No. 5,177,998. VRTC is in the process of refining the

test procedure for use with the IPMD, which is described in the report,

``Vehicle Inertial Parameters--Measured Values and Approximations,'' by

Garrott et al. of NHTSA's VRTC. Copies of both the patent and the

report have been placed in Docket No. 91-68, Notice 03.

2. Tilt Table Angle

Some commenters to the ANPRM stated that the tilt table procedure

is not standard practice and its repeatability is not known. Other

commenters stated that the procedure was repeatable.

NHTSA examined two studies which concluded that the tilt table test

is a simple, repeatable method of estimating the static roll stability

of a vehicle. ``Sensitivity Analysis of the Tilt Table Test

Methodology'' is a study sponsored by the Motor Vehicle Manufacturers

Association and conducted by the University of Michigan Transportation

Research Institute (UMTRI-91-48 December 1991). UMTRI found the tilt

table test to be repeatable in their laboratory and found nothing to

prevent site-to-site reproducibility. The other study is a NHTSA study

which found the following parameters to be critical to achieving an

accurate tilt table angle: slow, steady lift rate, minimal platform

deflection, platform angle measurement accurate to 0.1 degree, and

accuracy of measurement of the point at which the last tire leaves the

table (DOT HS 807 747 May 1991).

Based on these studies, NHTSA believes that the tilt table test

would result in repeatable measurements if conducted under specified

conditions. The agency's results for either tests on identical vehicles

or multiple tests on the same vehicle show the repeatability of tilt

table angle to be within the required accuracy of one degree. To ensure

repeatability, NHTSA has included specific test conditions in the tilt

table angle test procedure.

D. Timing of Information Provided by the Manufacturers and NHTSA

By each January 1st, each manufacturer would be required to report

to NHTSA the stability metric for each vehicle to be manufactured on or

after the next September 1 and on or before the first August 31

following that September 1st. Thus, the information for ``1997 model

year'' vehicles (vehicles manufactured between September 1, 1996 and

August 31, 1997) would have to be reported by January 1, 1996. NHTSA

recognizes that not all manufacturers change to production of a new

model year on the same date. If a manufacturer changes production on a

date after September 1, and the difference between model years affects

the stability metric, the manufacturer would have to report a metric

for two ``vehicles'' for a single make/model. NHTSA requests comments

on these proposed dates. NHTSA would consider changing the beginning

and ending date of the annual production period specified in this

regulation if there was a different date that coincides with a majority

of manufacturers' ``model year.''

If option one, which is a quantitative measure based on vehicle

metric calculations, were chosen for a final rule, NHTSA would use the

information provided by the manufacturers to supply manufacturers with

ranges for all passenger cars and light trucks for the upcoming model

year by April 1 of that year (i.e., in the above example, NHTSA would

provide manufacturers ranges for 1997 model year vehicles by April 1,

1996.) If option two were chosen, NHTSA would use the information

provided to provide manufacturers with the ``rating'' which must be

labeled on the vehicle. Since there is a possibility that this

information could not be provided by April 1, the agency requests

comments on how much leadtime manufacturers would need to place the

information on labels and in owner's manuals on all vehicles

manufactured on or after September 1.

NHTSA is proposing to make this new regulation effective on January

1, 1996, based on the presumption that this would give manufacturers at

least one year to complete testing necessary to report the tilt table

angle and/or critical sliding velocity for all vehicles following

publication of a final rule.

E. Benefits

As stated previously, NHTSA anticipates that this consumer

information regulation will result in a more informed public which,

through purchasing and/or driving decisions, could improve motor

vehicle safety. Similarly, consumer purchasing behavior could affect

manufacturers' design and/or marketing of vehicles. The agency is

unable to quantify at this time the benefits of this rulemaking. A more

detailed discussion of the possible benefits of this rulemaking can be

found in the Preliminary Regulatory Evaluation.

F. Costs

The costs associated with the proposed consumer information

regulation would arise from three different activities: generating the

stability metric for the label, printing the labels, and affixing

labels to the vehicles. This rule would not require manufacturers to

make vehicle changes. While such modifications are desirable, they are

not mandated, and if they occurred, would be the indirect result of

market forces and not a direct result of this rulemaking.

As explained in detail in the Preliminary Regulatory Evaluation,

NHTSA estimates that the total testing and labeling costs of a

regulation based on critical sliding velocity would range from $4.71 to

$6.35 million and the total cost of a regulation based on tilt table

angle would range from $3.93 to $5.57 million.

VIII. Final Stage Manufacturers and Alterers

NHTSA requests comments on how final stage manufacturers and

alterers would comply with the proposed consumer information

regulation. Would final stage manufacturers and alterers have

sufficient information on upcoming model year vehicles to report the

tilt table angle and/or critical sliding velocity of the vehicles they

will be producing by January 1 as required? How much information can

incomplete vehicle manufacturers pass on to final stage manufacturers

to assist them in predicting the tilt table angle or critical sliding

velocity of the final vehicle, and when?

NHTSA also asks for comment on how many vehicles in this category

would have a GVWR of 4,536 kilograms or less.

Given that many of these vehicles are manufactured for special

uses, NHTSA requests comments on whether certain types of vehicles

(e.g., walk-in van-type vehicles, campers, and motor homes) should be

excluded from the consumer information requirement. Would consumer

choice for these special-use vehicles be affected by the information

provided by this proposed regulation?

IX. Rulemaking Analyses and Notices

A. Executive Order 12866 and DOT Regulatory Policies and Procedures

NHTSA has examined the impact of this rulemaking action and

determined that it is ``significant'' within the meaning of E.O. 12866

and the Department of Transportation's regulatory policies and

procedures. This rulemaking was reviewed under E.O. 12866. The agency's

detailed analysis of the economic effects can be found in the

Preliminary Regulatory Evaluation available in the docket for this

rulemaking. The agency estimates that the proposed regulation would

cost $3.93 to $6.35 million annually.

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

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

small entities. As explained above, NHTSA does not expect any

significant economic impacts from this proposed rule. While the agency

has asked questions regarding the availability of data to certain

manufacturers who could be small businesses (final stage manufacturers

and alterers), NHTSA believes that these manufacturers will be able to

obtain sufficient information on the vehicles they complete or alter

that this proposed regulation will not impose a significantly different

burden on these manufacturers.

C. Paperwork Reduction Act

The reporting requirements associated with this proposed rule will

be submitted to the Office of Management and Budget for approval in

accordance with 44 U.S.C. chapter 35. Administration: National Highway

Traffic Safety Administration; Title: Vehicle Rollover Stability

Consumer Information Regulation; Need for Information: To determine

vehicle metric ranges for each model year; Proposed Use of Information:

Metric ranges will be provided to manufacturers for inclusion on

vehicle label; Frequency: Annual; Burden Estimate: 192 hours;

Respondents: 24; Form(s): None; Average Burden Hours for Respondent: 8.

D. National Environmental Policy Act

NHTSA has also analyzed this proposed rule under the National

Environmental Policy Act and determined that it would not have a

significant impact on the human environment.

E. Executive Order 12612 (Federalism)

NHTSA has analyzed this proposal in accordance with the principles

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

proposed rule would not have significant federalism implications to

warrant the preparation of a Federalism Assessment.

F. Civil Justice Reform

This proposed rule would not have any retroactive effect. There is

no express statutory intent to preempt any State law. Section 105 of

the Safety Act (15 U.S.C. 1394) sets forth a procedure for judicial

review of final rules. That section does not require submission of a

petition for reconsideration or other administrative proceedings before

parties may file suit in court.

X. Effective Date of Final Rule

If adopted, the proposed amendments would become effective on

January 1, 1996.

XI. Submission of Comments

Interested persons are invited to submit comments on the proposal.

It is requested but not required that 10 copies be submitted.

All comments must not exceed 15 pages in length. (49 CFR 553.21).

Necessary attachments may be appended to these submissions without

regard to the 15-page limit. This limitation is intended to encourage

commenters to detail their primary arguments in a concise fashion.

If a commenter wishes to submit certain information under a claim

of confidentiality, three copies of the complete submission, including

purportedly confidential business information, should be submitted to

the Chief Counsel, NHTSA, at the street address given above, and seven

copies from which the purportedly confidential information has been

deleted should be submitted to the Docket Section. A request for

confidentiality should be accompanied by a cover letter setting forth

the information specified in the agency's confidential business

information regulation. 49 CFR part 512.

All comments received before the close of business on the comment

closing date indicated above for the proposal will be considered, and

will be available for examination in the docket at the above address

both before and after that date. To the extent possible, comments filed

after the closing date will also be considered. Comments received too

late for consideration in regard to the final rule will be considered

as suggestions for further rulemaking action. Comments on the proposal

will be available for inspection in the docket. The NHTSA will continue

to file relevant information as it becomes available in the docket

after the closing date, and it is recommended that interested persons

continue to examine the docket for new material.

Those persons desiring to be notified upon receipt of their

comments in the rules docket should enclose a self-addressed, stamped

postcard in the envelope with their comments. Upon receiving the

comments, the docket supervisor will return the postcard by mail.

List of Subjects in 49 CFR Part 575

Consumer protection, Incorporation by reference, Labeling, Motor

vehicle safety, Motor vehicles.

In consideration of the foregoing, it is proposed that 49 CFR part

575 be amended as follows:

PART 575--CONSUMER INFORMATION REGULATIONS

1. The authority citation for part 575 of title 49 would continue

to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1407, 1421, and 1423;

delegation of authority at 49 CFR 1.50.

2. Part 575 would be amended by adding a new Sec. 575.102 to read

as follows:

Sec. 575.102 Vehicle Rollover Stability.

(a) Purpose and Scope. This section requires motor vehicle

manufacturers to provide information on the resistance of vehicles to

rollover to aid consumers in making an informed choice in the purchase

of new motor vehicles.

(b) Application. This section applies to passenger cars, and to

multipurpose passenger vehicles and trucks with a GVWR of 4,536

kilograms or less, and to manufacturers and dealers of such vehicles.

Alternative One

whole kilometer per hour, in the case of a calculated critical sliding

velocity value (expressed in kilometers per hour) that falls above a

whole number by 0.00 to 0.49 kilometers per hour, and the next higher

whole kilometer per hour, in the case of a calculated critical sliding

velocity value (expressed in kilometers per hour) that falls above a

whole number by 0.50 to 0.99 kilometers per hour.

Critical Sliding Velocity (CSV) for a vehicle is the value

determined, in kilometers per hour, from the equation:

TP28JN94.002

where,

TP28JN94.003

and

Ixx=roll mass moment of inertia of the vehicle, in kilogram-

kilometers2

g=gravitational constant, in kilometers/hour2

M=mass of the vehicle, loaded, in kilograms

hcg=center of gravity height of the vehicle, in kilometers

TW=the average of the front and rear track width of the vehicle, in

kilometers.

Production year means the period from September 1 of a calendar

year to August 31 of the next calendar year, inclusive.

Vehicle means a group of vehicles within a make, model, or car

division which have a degree of commonality in construction (e.g.,

body, chassis). It does not consider any level of decor, opulence, or

other characteristics that do not affect CSV.

(d) Reporting Requirements--(1) Reporting. On or before January 1

of each calendar year, beginning with the 1996 calendar year, each

manufacturer shall report to the Administrator a CSV for each vehicle

to be manufactured in the production year beginning on September 1 of

that calendar year. The CSV shall be accurate to the nearest kilometer

per hour. In reporting a CSV, the manufacturer shall list the

vehicle(s) to which it applies.

(2) Information. On or before April 1 of each calendar year,

beginning with the 1996 calendar year, the Administrator, based on the

information provided by all manufacturers under paragraph (d)(1) of

this section, provides manufacturers with the passenger car and

multipurpose passenger vehicle/truck CSV ranges to appear on the

vehicle label and in the owner's manual under paragraphs (e)(1)(i)

through (e)(1)(iii) of this section.

(e) Label--(1) Attachment and Maintenance of Label. (i) Each

vehicle manufactured on or after September 1, 1996 shall have affixed

to it a vehicle rollover stability label as described in paragraph

(e)(3) of this section. Each manufacturer shall affix or cause to be

affixed the labels required by this paragraph at the final assembly

point.

(ii) Each dealer shall maintain or cause to be maintained, any

vehicle rollover stability label on the vehicles it receives until the

vehicles are sold to consumers for purposes other than resale. If a

label becomes damaged so that any of the information on it is not

legible, the dealer shall replace it by affixing an identical,

undamaged label.

(iii) Each vehicle required by paragraph (e)(1)(i) of this section

to have a vehicle rollover stability label shall have in the vehicle

owner's manual the same information required to be on the label under

paragraphs (e)(3)(i) through (e)(3)(vii) of this section.

(2) Location of Label. (i) The label required by paragraph

(e)(1)(i) of this section shall be affixed on a side window of the

vehicle in a manner so that it can be read from outside the vehicle.

(ii) The label shall be either a separate label, a part of the

price information label required by 15 U.S.C. Sec. 1232, or a part of

the fuel economy label required by 15 U.S.C. Sec. 2006. If the rollover

stability label is separate and the window is not large enough to

contain both the price information label and the rollover stability

label, it shall be affixed on a side window, as close as possible to

the price information label.

(3) Label Requirements. (i) Each rollover stability label shall be

rectangular, not less than 114 mm high by 178 mm wide, and shall be in

the exact format shown in Figure 1. Each label shall bear the exact

wording shown in Figure 1. The CSV in the circle shall be the CSV

reported to the Administrator pursuant to paragraph (d)(1) of this

section for the labeled vehicle and the square brackets shall be

replaced by CSV range data given to the vehicle manufacturer by the

Administrator pursuant to paragraph (d)(2) of this section for the

production year of the labeled vehicle.

BILLING CODE 4910-59-P

TP28JN94.004

BILLING CODE 4910-59-C

(ii) The color of the label picture and text shall contrast with

the background of the label.

(iii) All rollover stability information on the label shall be

completely surrounded by a border at least 3 mm wide which contrasts

with the background of the label.

(iv) The title, ``Vehicle Rollover Stability,'' shall be centered

over the label and shall be printed in bold caps no smaller than 12

points.

(v) The remainder of the label text shall be 10 points.

(vi) The illustration of the vehicle in Figure 1 shall be centered

in a square not less than 50 mm on each side. The inside diameter of

the circle in which the CSV appears shall be no smaller than 16 mm. The

CSV figure shall be centered in the circle and no smaller than 10 mm in

height.

(f) Test Conditions--(1) Test Device. Measurement of center of

gravity height and roll moment of inertia are done on the Inertial

Parameter Measuring Device (IPMD). The IPMD is described in United

States Patent No. 5,177,998. A copy of the patent is available in

Docket No. 91-68, Notice 03.

(2) Vehicle--(i) The test vehicle has all fluids, other than fuel,

at the full level. The fuel tank and the fuel system are filled as

specified in S7.1.1 and S7.1.2 of Sec. 571.301 of this title.

(ii) The vehicle's seat is positioned according to S8.1.2 and

S8.1.3 of Sec. 571.208 of this title.

(iii) Tires used during the test are of the same size and

construction recommended by the manufacturer for the vehicle. The tires

have accumulated not less than 80 and not more than 1620 kilometers.

Not less than 80 of those kilometers are accumulated at a speed of not

less than 80 kilometers per hour. All tires are clean and dry. All

tires are inflated to the vehicle manufacturer's recommended inflation

pressure for maximum vehicle loading and measured when the tire is

cold.

(iv) All vehicle openings (doors, windows, hood, trunk, convertible

top, etc) are in the closed position.

(3) Load. A Hybrid III Test Dummy, as defined in Subpart E of

Sec. 572 of this title, is placed in the left front seating position,

positioned according to S11 of Sec. 571.208 of this title, and secured

with the vehicle's safety belt system, whether manual or automatic. The

dummy may be placed in the test vehicle before or after moving the

vehicle onto the test device. The test vehicle carries no load other

than the test dummy.

(4) Ambient conditions. The measurements of the center of gravity

height and roll mass moment of inertia are made with both the vehicle

and the test device at a temperature not less than 4 and not more than

39 degrees Celsius. Air motion around the vehicle and device is less

than 6 kilometers per hour.

(g) Test Procedures. The test procedure for use with the IPMD is

described in the report, ``Vehicle Inertial Parameters--Measured Values

and Approximations,'' by Garrott et al. of NHTSA's VRTC. A copy of the

report is available in Docket No. 91-68, Notice 03.

Alternative Two

in the case of a measurement that falls above a whole number by 0.00 to

0.49 degrees, and the next higher whole degree, in the case of a

measurement that falls above a whole number by 0.50 to 0.99.

Production year means the period from September 1 of a calendar

year to August 31 of the next calendar year, inclusive.

Tilt table angle (TTA) means, with respect to a motor vehicle

placed on a tilt table, the angle between the horizontal and the

platform of the tilt table when the last uphill tire of the vehicle

ceases contact with the platform surface.

Vehicle means a group of vehicles within a make, model, or car

division which have a degree of commonality in construction (e.g.,

body, chassis). It does not consider any level of decor, opulence, or

other characteristics that do not affect TTA.

(d) Reporting Requirements--(1) Reporting. On or before January 1

of each calendar year, beginning with the 1996 calendar year, each

manufacturer shall report to the Administrator a TTA for each vehicle

to be manufactured in the production year beginning on September 1 of

that calendar year. The TTA shall be accurate to the nearest degree. In

reporting a TTA, the manufacturer shall list the vehicle(s) to which it

applies.

(2) Information. On or before April 1 of each calendar year,

beginning with the 1996 calendar year, the Administrator, based on the

information provided by all manufacturers under paragraph (d)(1) of

this section, provides manufacturers with the passenger car and

multipurpose passenger vehicle/truck TTA ranges to appear on the