Trailer rear impact protection upgrades

Since 1998, a pair of Federal Motor Vehicle Safety Standards (FMVSS) have been in effect to reduce deaths and serious injuries that occur when light-duty vehicles collide with the rear end of trailers and semitrailers — FMVSS 223: Rear Impact Guards, and FMVSS 224: Rear Impact Protection. These standards work symbiotically to establish impact guard features and performance requirements, as well as the applicable trailers to be equipped, along with certification of individual guards by the manufacturers. FMVSS 223, an equipment standard, specifies strength and energy absorption requirements in quasi-static force tests of rear impact guards sold for installation on new trailers and semitrailers. FMVSS 224, a vehicle standard, requires new trailers and semitrailers with a gross vehicle weight rating (GVWR) of 10,000 pounds or more to be equipped with a rear impact guard meeting FMVSS 223. Note, this standard is inclusive of trailers with a 10,000-pound GVWR. In a July 15, 2022, final rule, National Highway Traffic Safety Administration (NHTSA) upgraded FMVSS 223 to improve the equipment standard’s performance requirements and align with other standards. Key points This final rule adopts requirements of Canada Motor Vehicle Safety Standard (CMVSS) 223: Rear Impact Guards, which requires rear impact guards with sufficient strength and energy absorption capability to protect occupants of compact and subcompact passenger cars impacting the rear of trailers at 35 mph, so the changes to the U.S. requirements now harmonize with those of the current CMVSS. Additionally, the current requirements in FMVSS 223 and FMVSS 224 were developed with the intent of providing underride crash protection to occupants of passenger vehicles in impacts up to 30 mph, which worked in conjunction with the same speed used at that time in FMVSS 208_ Occupant Crash Protection. Since then, the test speed in FMVSS 208 has been increased to provide high levels of occupant protection in a 35 mph frontal crash, and the upgraded performance requirements of FMVSS 223 now align with this increased speed. Guards manufactured under these new requirements will provide upgraded protection in crashes where a passenger motor vehicle hits the center of the rear of a trailer, as well as those where half of the passenger vehicle width overlaps the rear of the trailer. This final rule also adopts Transport Canada’s definition of ‘‘rear extremity’’ to define where aerodynamic fairings are to be located on a trailer to avoid posing a safety hazard in rear underride crashes. The effective date of the final rule is Jan. 11, 2023, with a compliance date of July 15, 2024, for trailers manufactured on or after that date. Optional early compliance is permitted. The presence and condition of the guards is included in the annual inspection criteria required under the Federal Motor Carrier Safety Regulations. See CFR 49, Appendix A to Part 396 — Minimum Periodic Inspection Standards. Liftgate exclusions As part of the two-standard method for trailer rear impact protection, FMVSS 223 contains requirements for the guards and FMVSS 224 determines which trailers must be equipped with those guards. Section 3 (S3) of FMVSS 224 sets the application of the trailers subject to the requirements of FMVSS 223, and lists those to which the standard applies as well as those excluded. Under the July 15, 2022 final rule, the standard “does not apply to pole trailers, pulpwood trailers, low chassis vehicles, road construction controlled horizontal discharge trailers, special purpose vehicles, wheels back vehicles, or temporary living quarters as defined in 49 CFR 523.2.” While the final rule does not change the excluded trailer types, it does include some corrections to the applications in S3 of FMVSS 224. Notably, the omission of “low chassis vehicles” in the list of excluded vehicles as well as the citation referenced in the definition of “temporary living quarters.” A common question regarding this list of excluded trailers comes from those attempting to find a liftgate exemption. While there is no specific exclusion for liftgates, the definition of special purpose vehicles (see the following from FMVSS 224, S4) would describe some, but not all, forms of liftgate-equipped trailers NHTSA has excluded. “Special purpose vehicle means a trailer or semitrailer that: (1) Has work performing equipment that, while the vehicle is in transit, resides in or moves through any portion of the space bounded_ (i) Vertically from the ground to a horizontal plane 660 mm above the ground; (ii) Laterally the full width of the trailer, determined by the trailer’s side extremities as defined in S4 of this section; and (iii) From the rear extremity of the trailer as defined in S4 of this section to a transverse vertical plane 305 mm forward of the rear extremity of the trailer; or (2) Is equipped with a loading platform that, while the vehicle is in transit, is completely stowed in the space bounded by a plane tangent to the underside of the vehicle, the ground, the rear extremity of the vehicle, and the rearmost axle, and that, when operated, deploys from its stowed position to the rear of the vehicle through any portion of the space described above.” This is not a newly excluded trailer type. Again, the final rule did not change the application, but rather made technical corrections to the applicability section of FMVSS 224. Related confusion FMVSS 223 and 224 do not apply to trucks. However, there are truck rear end protection requirements that fall under the Federal Motor Carrier Safety Regulations (FMCSRs) as commercial motor vehicles (CMVs; see following definition). While these sound the same, they are not, and it’s important to note that the FMCSRs apply to the motor carrier operating the CMV, not its manufacturer. CFR 49, Part 393.86 contains rear end protection requirements for CMVs, which includes trucks with a GVWR of more than 10,000 pounds. It also includes the application and exceptions to the requirements. Although the guards often used for these requirements may look similar to those required on new, heavy trailers, the FMCSRs do not contain the performance requirements of FMVSS. Rather, rear impact guards “must be substantially constructed and attached by means of bolts, welding, or other comparable means.” The rear end protection requirements of the FMCSRs contain the following provision to allow alternative means of providing this same protection: “49 CFR 393.86(b)(3) Vehicle components and structures that may be used to satisfy the requirements of paragraph (b) of this section. Low chassis vehicles, special purpose vehicles, or wheels back vehicles constructed and maintained so that the body, chassis, or other parts of the vehicle provide the rear end protection comparable to impact guard(s) conforming to the requirements of paragraph (b)(1) of this section shall be considered to be in compliance with those requirements.” This section of the FMCSRs can easily become another source of confusion, misconception and misinformation for those attempting to find a liftgate exemption as it would apply to trucks, but note that the term “special purpose vehicle” is also used here in the list of excluded vehicles. Reviewing the portion of the definition for this term as it’s used in the FMCSRs and applicable to straight trucks reveals a similar description to that used by NHTSA for trailers. “49 CFR 393.5 Special purpose vehicle… (2) A motor vehicle, not described by paragraph (1) of this definition, having work-performing equipment that, while the motor vehicle is in transit, resides in or moves through the area that could be occupied by the horizontal member of the rear impact guard, as defined by the guard width, height and rear surface requirements of § 393.86(b)(1).” As with trailers under FMVSS, there is no specific liftgate exclusion from the rear end protection requirements for trucks under the FMCSRs. However, the special purpose vehicle description would apply to some, but not all, forms of liftgate-equipped trucks.

Trailer rear impact protection upgrades

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