GAO issues truck underride report — NTEA views reflected

By Mike Kastner, NTEA managing director

This article was published in the June 2019 edition of NTEA News

U.S. Government Accountability Office (GAO) recently issued a report, in which NTEA participated, concerning truck underride guards. Requested by Congress, it calls for better data and research into truck underride crashes.

A truck underride crash, which does not happen often, occurs when a car slides under a large truck — typically a tractor-trailer. GAO found all truck underride crashes from 2008–2017 represented less than 1% of total traffic fatalities. In a previous rulemaking, National Highway Traffic Safety Administration (NHTSA) estimated single-unit trucks were involved in only a fraction of crashes compared to tractor-trailers and that rear underride guards on single-unit trucks were only about 20% effective.

Trailers are currently required to have a rear underride guard. Under Federal Motor Carrier Safety Administration (FMCSA) regulations, owners of single-unit trucks are required to maintain rear guards (ICC bumpers) on certain vehicles for which the rear of the body is more than 30 inches above the ground.

Current regulatory activity

NHTSA proposed strengthening rear guard requirements for trailers in 2015 but has not issued any new regulations. It estimates about 95% of all newly manufactured trailers already meet the stronger proposed requirements.

Similarly, in 2015, NHTSA issued an advance notice of proposed rulemaking (ANPRM) to consider requiring rear guards with strength and energy absorption criteria for all newly built single-unit trucks. It also proposed requiring single-unit trucks to install red and white retroreflective tape meant to increase visibility.

NTEA discussed the proposed requirements with NHTSA, providing market information, associated costs and accident data analysis. NHTSA, which subsequently found requirement costs outweighed the benefits, withdrew the ANPRM.

Side underride guards are being developed, but according to GAO, there are usage challenges due to the cost and additional weight. One aftermarket manufacturer made a side underride guard for trailers that was successfully crash-tested at 35 and 40 miles per hour. These guards add up to 800 pounds to the trailer. Similar technologies — including aerodynamic side skirts and pedestrian/cyclist side guards — are being installed on some trailers and single-unit trucks, but are not meant to mitigate underride crashes.

NHTSA plans to complete research on front underride guards, but the bumper and lower frame of trucks typically used in the U.S. may mitigate the need for front guards for underride purposes.

Congressional interest
The GAO study was requested by sponsors of legislation introduced last year and again this year that would require underride guards on trucks and trailers. Last year’s legislation died without any action being taken. The new bills, known as Stop Underrides Act of 2019, are H.R. 1115 and S. 665. 

This legislation would require the use of rear, side and front underride guards as applicable on all trucks and trailers, including both newly manufactured vehicles and the existing fleet. During discussions with GAO’s research team, NTEA conservatively estimated first-year costs associated with the legislation at over $200 billion.

NTEA’s $200 billion estimate for full compliance with the proposed legislation as introduced (front, rear and side protection on all new and existing trucks and trailers) is based on today’s costs of such guards along with existing fleet size and annual production rates. 

This conservative figure includes the first year only of new truck and trailer production along with retrofitting the existing truck and trailer fleet. Annual costs would likely exceed $7–8 billion.

The largest portion of these costs would be retrofitting the existing truck and trailer fleet. The single most expensive requirement would likely be the cost associated with installation of side guards on existing trailers.

GAO recommendations
Based in part on NTEA’s cost estimates and analysis of existing data, GAO issued four recommendations, primarily centered on the need for better data and research. 

Recommendation 1
NHTSA’s administrator should recommend to the expert panel of the Model Minimum Uniform Crash Criteria to update the criteria to provide a standardized definition of underride crashes and include underride as a recommended data field. 

Recommendation 2
NHTSA’s administrator should provide information to state and local police departments on how to identify and record underride crashes. 

Recommendation 3
FMCSA’s administrator should revise Appendix G of the agency’s regulations to require that rear guards are examined during commercial vehicle annual inspections. 

Recommendation 4
NHTSA’s administrator should conduct additional research on side underride guards to better understand the overall effectiveness and cost associated with these guards and, if warranted, develop standards for implementation.

Learn more
Access a full copy of the GAO study at

For more legislative and regulatory information, visit