DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2022-0053]
Federal Motor Vehicle Safety Standards; Rear Impact Guards; Rear Impact Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of
Transportation (DOT).
ACTION: Response to petition for reconsideration.
SUMMARY: This document denies a petition, submitted by Advocates for Highway and Auto
Safety, the Truck Safety Coalition, Citizens for Reliable and Safe Highways, and Parents Against
Tired Truckers, for reconsideration of a final rule amending Federal Motor Vehicle Safety
Standard (FMVSS) No. 223, “Rear impact guards,” and FMVSS No. 224, “Rear impact
protection.” The final rule, published on July 15, 2022, upgraded NHTSA’s standards
addressing rear underride protection in crashes of passenger vehicles into trailers and semitrailers
by requiring rear impact guards to provide sufficient strength and energy absorption to protect
occupants of compact and subcompact passenger cars impacting the rear of trailers at 56
kilometers per hour (km/h) (35 miles per hour (mph)).
DATES: [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER].
FOR FURTHER INFORMATION CONTACT:
For technical issues: Ms. Lina Valivullah, National Highway Traffic Safety Administration,
1200 New Jersey Avenue SE, West Building, Washington, DC 20590, (telephone) (202) 3668786, (email) Lina.Valivullah@dot.gov.
For legal issues: Ms. Callie Roach, Office of the Chief Counsel, National Highway Traffic
Safety Administration, 1200 New Jersey Avenue SE, West Building, Washington, DC 20590,
(telephone) (202) 366-2992, (email) Callie.Roach@dot.gov.
SUPPLEMENTARY INFORMATION:

I. Background
The final rule addressing rear underride protection, which was published in the Federal
Register on July 15, 2022,1 upgraded NHTSA’s safety standards for rear underride protection in
crashes of passenger vehicles into trailers and semitrailers by adopting requirements similar to
Transport Canada’s standard for rear impact guards. With this final rule, the standards now
require rear impact guards to provide sufficient strength and energy absorption to protect
occupants of compact and subcompact passenger cars impacting the rear of trailers at 56
kilometers per hour (km/h) (35 miles per hour (mph)). The final rule provides upgraded
protection for crashes in which a passenger motor vehicle hits the rear of the trailer or semitrailer
such that 50 to 100 percent of the width of the passenger motor vehicle overlaps the rear of the
trailer or semitrailer.
NHTSA initiated this rulemaking in response to petitions for rulemaking from the
Insurance Institute for Highway Safety (IIHS) and from Ms. Marianne Karth and the Truck
Safety Coalition. The final rule also responded to and fulfilled the rulemaking mandate of
Section 23011(b)(1)(A) of the Infrastructure, Investment and Jobs Act, Pub. L. 117-58
(commonly referred to as the Bipartisan Infrastructure Law or BIL), which directs the Secretary
(by delegation, NHTSA) to upgrade the Federal safety standards for rear impact guards. NHTSA
also issued the final rule in accordance with DOT’s January 2022 National Roadway Safety
Strategy, which describes the five key objectives of the Department’s Safe System Approach:
safer people, safer roads, safer vehicles, safer speeds, and post-crash care. One of the key
Departmental actions to enable safer vehicles was to issue a final rule to upgrade existing
requirements for rear impact guards on newly manufactured trailers and semitrailers.
In accordance with the Administrative Procedure Act,2 NHTSA’s regulations specify, at
49 CFR 553.35, that any interested person may petition NHTSA for reconsideration of any final

87 FR 42339.
5 U.S.C. § 553(e) requires that each agency provide interested persons the right to petition for the issuance,
amendment, or repeal of a rule.
1
rule by filing a petition within 45 days after publication of the final rule in the Federal Register.
As required by 49 CFR 553.35(a), the petition must contain a brief statement of the complaint
and an explanation why compliance with the rule is not practicable, is unreasonable, or is not in
the public interest.
II. Petitions for Reconsideration
NHTSA received two petitions in response to the final rule. The first petition was
submitted by Jerry and Marianne Karth, Aaron Kiefer, Eric Hein, Lois Durso-Hawkins, Andy
Young, and Garrett Mattos and dated July 15, 2022.3 That petition did not meet the requirements
in 49 CFR part 553 for a petition for reconsideration and NHTSA will instead treat and respond
to it as a petition for rulemaking in a separate notice.4
The second petition, dated August 25, 2022, was submitted by Advocates for Highway and
Auto Safety (Advocates), the Truck Safety Coalition (TSC), Citizens for Reliable and Safe
Highways (CRASH), and Parents Against Tired Truckers (PATT), referred to collectively as
“Advocates et al.” throughout this document.5 The petitioners disagreed with the data and
analysis that the agency used for the final rule and asserted that NHTSA should require
reinforced rear guards designed for the 30 percent overlap crash condition. The petitioners stated
that the lesser requirements established by the final rule are “inadequate and dangerous” and will
increase market demand for weaker guards, leading to additional fatalities. The petitioners
asserted that the final rule is not in the public interest and requested a stay of the effective date.
III. Response to Petition
a. Crash Data and Underreporting

Docket No. NHTSA-2022-0053-0003, document titled “Petition for Reconsideration of the Rear Impact Guard
Rule (July 2022)”, available at https://www.regulations.gov/document/NHTSA-2022-0053-0003.
4 While it was submitted as a petition for reconsideration of the final rule, the petition did not explain “why
compliance with the rule is not practicable, is unreasonable, or is not in the public interest,” as required by 49 CFR
part 553. In addition, the petitioners did not assert that the requirements established by the final rule should be
stayed or revoked. For these reasons, the petition does not meet the requirements in 49 CFR part 553 for a petition
for reconsideration.
5 Docket No. NHTSA-2022-0053-0004, available at https://www.regulations.gov/document/NHTSA-2022-00530004.
Petitioners’ Assertions
The petitioners claimed that NHTSA did not fully consider the available data on underride
crashes. They cited statistics regarding the number of fatal large truck crashes in recent years,
the cost of crashes involving trucks and buses, and the occupational hazards of truck driving.
They asserted that NHTSA’s data analysis was incorrect because it relied on a single University
of Michigan Transportation Research Institute (UMTRI) study and did not account for
underreporting of underride crashes. They claimed that the UMTRI study was faulty due to its
use of police reports and the Fatality Analysis Reporting System (FARS), which they assert do
not properly identify underride crashes. The petitioners also stated that NHTSA ignored
recommendations from IIHS, the National Transportation Safety Board (NTSB), and the
Government Accountability Office (GAO) regarding underride data collection, including the
2019 GAO recommendation6 to include underride in the Minimum Modal Uniform Crash
Criteria.
Agency Response
The petitioners raised substantially similar points in comments they submitted during the
rulemaking process. NHTSA carefully reviewed all information submitted by the petitioners and
commenters throughout the rulemaking process to inform the final rule. The agency gave full
consideration to the comments submitted in response to the NPRM, including those regarding
underride crash data and underreporting. No new data was provided in this petition for
reconsideration; the statistics cited by Advocates et al. are not specific to truck crashes with light
passenger vehicles and do not provide information on underride. The concerns raised about the
data on rear underride crashes used to inform rulemaking were addressed in the preamble to the
final rule.

Government Accountability Office. 2019. Truck underride guards: Improved data collection, inspections, and
research needed. GAO-19-264.
As explained in the preamble (at 87 FR 42354), NHTSA’s analysis did not rely on underride
coding in FARS or in police reports, and instead used TIFA7 data with supplemental information
reported in the 2013 UMTRI Study. The TIFA database has greater accuracy than FARS for all
medium and heavy trucks involved in fatal traffic crashes, providing more detailed information
on the involved large trucks, motor carriers, and sequence of events. The 2013 UMTRI Study
analyzed crash information to determine if the crashes might have been underride crashes even
when they were not categorized as such in the police reports and in FARS. The study gathered
additional information on the rear geometry of single unit trucks and trailers, the configuration of
rear impact guards on trucks and trailers, and the incidence and extent of underride and fatalities
in rear impacts with trucks and trailers. Because of the detailed analysis and the supplemental
information collected for each crash, the 2013 UMTRI Study forms the most comprehensive and
valid data set available to inform the agency regarding crashes involving trucks and trailers and
the incidence of underride. The crash severity and occurrence of passenger compartment
intrusion (PCI) were determined from the passenger vehicle information. Further, to avoid
underestimating underride fatalities, the agency’s analysis of the UMTRI study considered all
crashes with PCI to be underride even though large striking vehicles may sustain PCI in crashes
without underride due to high impact speed and other factors.
NHTSA acknowledges that there is undercounting of underride crashes in FARS and in
police reports, which is partly why NHTSA did not rely on these sources in the final rule.
NHTSA is taking steps to improve data collection to support future rulemaking. NHTSA and the
Federal Motor Carrier Safety Administration have developed and provided educational materials
to State and local police departments on identifying and recording underride crashes. An
underride data element was also included in the recently published “Minimum Modal Uniform

The Trucks in Fatal Accidents (TIFA) database contains records for all trucks with a gross vehicle weight rating
greater than 4,536 kg (10,000 lb) that were involved in fatal traffic crashes in the 50 states and District of Columbia.
Crash Criteria” 6th Edition,8 as recommended in the 2019 GAO report. In addition to the
education materials NHTSA provided to State and local police departments, NHTSA will
continue to provide training and guidance resources to the law enforcement community to
improve accuracy and consistency in the reporting of truck underride crashes.
b. 30 Percent Overlap Protection
Petitioners’ Assertions
The petitioners claimed that NHTSA failed to fulfill what they describe as a BIL mandate to
match IIHS TOUGHGUARD performance9 and that NHTSA did not address the guard
deficiencies that IIHS previously identified for 30 percent overlap protection. The petitioners
stated that some trailer manufacturers currently provide redesigned guards that meet the IIHS
TOUGHGUARD requirements as standard, and that Stoughton’s guard does not add weight or
cost. They asserted that NHTSA set an unreasonably low standard and there will be an “increase
in deaths and injuries that will result from an increase in market demand for weaker guards” due
to the requirements in the final rule.
Agency Response
The section in the final rule titled “NHTSA’s Statutory Authority and Response to BIL”10
described provisions of the Safety Act, relevant sections of the BIL, and fulfillment of BIL
mandates in relation to the final rule. The BIL made clear that NHTSA was to adopt a standard
for the 30 percent overlap condition if the standard met the Safety Act’s requirements and
considerations for a safety standard. The Safety Act requires, at 49 U.S.C. § 30111, motor
vehicle safety standards to be practicable, meet the need for motor vehicle safety, and be stated

The“ Minimum Modal Uniform Crash Criteria” 6th Edition was published on January 4, 2024, available at
https://www.nhtsa.gov/traffic-records/model-minimum-uniform-crash-criteria.
9 BIL does not contain such a mandate. The petitioners may be referring to appropriations report language urging
NHTSA to “to complete rulemaking to improve rear guards in order to ultimately meet the Insurance Institute for
Highway Safety standards for Toughguard awards.” House Report No. 117-99 at p. 53; see also the Joint
Explanatory Statement accompanying the Consolidated Appropriations Act, 2022 (Division L—Transportation,
Housing and Urban Development and Related Appropriations Act, 2022, P.L. 117-103). This and similar report
language must be read in the context of the specific statutory requirements to which NHTSA is subject under the
Safety Act.
10 87 FR 42341-42344.
in objective terms. Further, when establishing new FMVSS requirements, NHTSA must
consider whether a proposed standard is reasonable, practicable, and appropriate for the motor
vehicle type for which it is prescribed. While a particular trailer model may include a more
robust guard as standard, the agency must consider the effect of a mandate on all vehicles subject
to FMVSS No. 223 and FMVSS No. 224. As explained in the final rule (at 87 FR 4235942360), NHTSA has decided that an FMVSS that requires all covered vehicles (trailers and
semitrailers) to provide rear impact protection in full-frontal, 50 percent overlap, and 30 percent
overlap crashes at 56 km/h (35 mph) impact speed would not be reasonable or practicable and
would not meet the requirements of Sections 30111(a) and (b) of the Safety Act for issuance of
FMVSS.
The petitioners also did not provide any evidence to support the claim that the requirements
in the final rule may lead to market demand for weaker guards and a higher rate of fatalities and
injuries in comparison to current statistics. Nor does the agency believe that manufacturers will
cease selling guards that have received awards from IIHS. In the absence of sufficient
information to quantify potential changes in consumer behavior, accounting for such claims in
the regulatory analysis is not appropriate. As the requirements of the final rule are more
stringent than the preceding requirements, the agency does not agree that it would be in the
public interest to stay the final rule.
IV. Conclusion
For the reasons discussed above, the agency is denying the August 25, 2022 petition from
Advocates et al. for reconsideration of the July 15, 2022 final rule (87 FR 42339).
Issued in Washington, D.C., under authority delegated in 49 CFR 1.95 and 501.5.
Raymond R. Posten
Associate Administrator for Rulemaking
BILLING CODE 4910-59-P
[FR Doc. 2024-13957 Filed: 6/26/2024 8:45 am; Publication Date: 6/27/2024]