“The testing facility analysis, the independent expert’s analysis, and FHWA and NHTSA’s analysis were all done independently, and they all arrived at the same conclusion,” the FHWA statement says, adding all the data, videos, and analyses are available to the public.

In addition to the crash tests, a joint FHWA-AASHTO task force is currently evaluating a wide range of crash data and other information to assess in-service performance of the ET-Plus and whether the product has vulnerabilities outside of the NCHRP 350 testing. Those results are expected this summer. 

In May, FHWA changed its standards for approving guardrails, requiring modified devices to undergo crash-tests even if the product was deemed safe in the past under older guidelines. Roadside device makers and crash-test facilities must also disclose any financial conflicts of interest.

Nevertheless, FHWA and the ET-Plus remain under scrutiny. Six U.S. Senators led by Richard Blumenthal (D-Conn.) have called on the Government Accountability Office to investigate how the agency evaluates the safety of roadside hardware, including guardrails. FHWA’s relationship with Trinity is also the subject of a federal probe, with prosecutors in Boston having subpoenaed documents as far back as 1999 on the ET-Plus and a predecessor system.