ROADS/BRIDGES: FHWA defends guardrail test

On the heels of news that Trinity passed its recent test, agency defends its methods

March 17, 2015

Roads & Bridges recently reported that Trinity Industries Inc.’s guardrail system passed a second round of government crash tests, even as skeptics have maintained that the system may still lock up when hit and spear crashing cars instead of slowing them. State transportation officials have been awaiting the results from the Federal Highway Administration (FHWA), which stated that Trinity’s shock-absorbing ET-Plus system didn’t penetrate the cars in the four latest government-mandated tests.

On the heels of this announcement, the FHWA, which was charged with investigating the guardrail systems after a series of failures, has defended its methods in giving the system a passing grade despite severe impact damage to the driver’s door in the tests.

Suzanne Emmerling, a spokeswoman for the Federal Highway Administration, said on Saturday that the 2003 study into the system was “not applicable to the crash test results that were analyzed” for the ET-Plus, since that guideline had since been revised and was no longer used.

This past Friday, the agency said measurements taken of the lower part of the driver’s door showed it was pushed into the passenger compartment by 6.75 in. The agency concluded that the damage was not likely to cause serious injury, and that the ET-Plus deserved to pass. That prompted criticism from lawyers for the whistle-blower case that a guideline the Federal Highway Administration put in place before 2003 was ignored.

In 2003, the National Highway Traffic Safety Administration published a study at the request of the FHWA that stated the guideline for damage to the occupant compartment had been set at 6 in. deep. The study concluded that significant injuries were happening even when damage was less than 6 in., and suggested re-evaluating the guideline to potentially make it even stricter.

Ms. Emmerling said that the 2003 study on guardrail intrusion involved crash data where the damage happened to the front side panel area of the car, as well as the floor area near the driver’s feet, but not the door itself. Therefore, she said, the agency did not consider it relevant to the eighth ET-Plus test.

That test, conducted in late January, involved a 1998 Geo Metro traveling about 60 miles an hour. It was driven into an ET-Plus guardrail and spun out, causing the driver’s door to strike a bent piece of the metal guardrail and collapse inward. In video footage released on Friday by the agency, the crash test dummy can be seen being thrown to the side as the door caves in.