Guards Benefits and Costs

Well-designed energy-absorbing guards have the potential to save several times the deaths the injuries claimed by the National Highway Traffic Safety Administration (NHTSA)for those proposed "moderate-strength" guard and it’s permitted variants.

NHTSA claims that its proposed "rear impact guard" would save 9 to 19 of the 500 deaths and 776 to 114 of the 18,000 injuries each year in rear impact/underride crashes.

Advantages of energy-absorbing rear guards are:

· Many crashes resulting in passenger compartment intrusion underride that would occur with the NHTSA guard will be prevented by an energy-absorbing guard;

· Many fatalities in crashes with the NHTSA guard will be converted to injury-only crashes with an energy-absorbing guard;

· Many serious injuries will be converted to moderate-to-minor injuries in rear impacts if energy-absorbing guards are installed in lieu of the NHTSA guard;

· Many injury-producing crashes with the NHTSA guard will be converted to property-damage only crashes with energy-absorbing guards; and

· Energy-absorbing guards, regardless of injury quotients, reduce property damage to both trucks and passenger vehicles, given the same impact speed as with the NHTSA guard.

All contractors and tests are carried out in the U.S. and the United Kingdom consistently indicate much lower head injury scores for energy-absorbing guards. Also, higher closing speeds (30 mph-40 mph) with energy-absorbing guards still have lower injury scores.


A study called "The Cost of Highway Crashes" (Ted Miller et al, 1991) Conducted for the Federal Highway Administration (FHWA) determined the economic losses associated with highway fatalities and injuries. The study concluded that the average highway death costs $2.63 million and the average highway crash injury costs $44,000. (Note: of the 4.83 million injuries caused by highway crashes annually, 2 million are not medically treated while nearly 500,000 require hospitalization.)

An average of 500 passenger vehicle occupants are killed and over 18,000 are injured each year in rear impact crashes with trucks.

Based on the FHWA study’s cost estimates, rear impact crash fatalities create economic losses exceeding $1.3 billion annually and injuries result in nearly $8 billion lost each year.

Quinton-Hazell, one-time manufacturer of underride guards in the United Kingdom, claimed ten years ago that an energy-absorbing guard could cost as little as $170 (U.S.) if sold in quantity.

The Invertube energy-absorbing design today costs under $200 (U.S.)

Hope Enterprise’s Safe-T-Bar rubber-block energy-absorbing device apparently is the most affordable on the market today---probably less than $200 (U.S.)

In 25 years of rear impact/underride rulemaking, however, NHTSA has never performed a full benefits/costs analysis for an energy-absorbing guard side-by-side with the various evolving designs the agency has proposed.

The only benefits/costs information available is from Great Britain. Analyses in the late 1980’s on rigid front underride guards conclude that more than one-third of all front underride deaths can be prevented by front-of-truck guards if passenger vehicle occupants are wearing their seatbelts (Thomas and Clift 1991)

Robinson and Riley (1991) cite the above study and imply that energy-absorbing front underride guards could save even more lives. However, no benefits/costs was done for the energy-absorbing design.

Since European Economic Community and UK legislation for rear truck guards only specify initial static load strength, no regulation compels anyone to perform a benefits/costs analysis on energy-absorbing guard designs.