The Virginia Dept. of Transportation (VDOT) will begin replacing hundreds of ET-Plus guardrail terminals along its interstates and other high-speed roadways next year, now that a 14-month review of the controversial component’s performance in high-speed crashes has been completed.

The ET-Plus, manufactured by Trinity Industries, Dallas, has been blamed for numerous injuries and deaths over the past decade, despite repeated tests indicating that the device is safe. In June 2015, Trinity was ordered to pay $663-million court judgment in a whistleblower lawsuit that found the company had modified ET-Plus components in 2005 without notifying the Federal Highway Administration.

VDOT subsequently removed the ET-Plus from its list of approved guardrail equipment and undertook its own assessment of the terminal, which has been associated with seven reported crashes at 55 mph or greater in the state since October 2014. In each case, the guardrail penetrated the vehicle’s passenger compartment, causing non-fatal injuries.

In a series of six VDOT-funded tests between  Sept. 17 and Oct. 2 at an independent automotive and safety testing facility in California, the modified ET-Plus passed four standard National Cooperative Highway Research Program (NCHRP) impact tests.

But it failed a non-standard “shallow angle” test. When struck by a truck at a 5-degree angle, the end terminal’s failure to properly “spool” the guardrail caused the vehicle to overturn. The ET-Plus performed as designed in a similar shallow-angle impact test involving a passenger vehicle.

VDOT Chief Engineer Garrett Moore said at a press briefing that the 5-degree angle was chosen for testing in an attempt to determine the exact point at which the terminal becomes vulnerable to failure.

“Some of our testing was guesswork,” Moore said, adding that the results were consistent with tests performed by a joint American Association of State Highway and Transportation  Officials-FHWA task force in September.

With as many as 15,000 ET-Plus terminals currently installed along Virginia’s highways, Moore estimated that a complete replacement would cost as much as $100 million.

Because the ET-Plus appears to perform adequately when impacted at speeds less than 45 mph, VDOT will focus on replacing units along interstates and other high-speed roadways with end terminals that comply with AASHTO’s Manual for Assessing Safety Hardware (MASH). That process, Moore said, will still take many years to complete.

The replacement plan, set to begin in November 2016, will coincide with a new VDOT requirement for MASH-compliant end terminals in its new construction projects. The agency will also continue replacing damaged ET-Plus end terminals with agency-approved equipment. Moore estimates that  270 of these terminals have been replaced over the past six months.

Moore expressed no qualms about continuing to do business with Trinity, which currently offers the only MASH-compliant end-terminal eligible for federal-aid reimbursement, according to FHWA.

A Trinity spokesman said in a statement that the ET Plus “has been thoroughly reviewed by federal and state highway officials and multiple independent experts.” He added, “Since its introduction, the ET Plus System has met [National Cooperative Highway Research Program report] 350 standards, has been accepted by the FHWA for use on the nation’s highways and has an unbroken chain of eligibility for federal aid reimbursement.”

He said, “The ET Plus System is the most successfully crash-tested product of its kind,” adding that VDOT’s tests had confirmed that the product “meets NCHRP 350 standards.”

Trinity also had strongly criticized VDOT’s testing program in newspaper ads that appeared across the state in September.

Moore expressed hope that, when VDOT has its specifications in place in November “we’ll start to see some competition” from other manufacturers with MASH-approved end terminals. An FHWA spokesperson said the agency has no pending requests to determine federal aid eligibility for new terminals.

Moore also said that VDOT was in discussions with other guardrail-terminal manufacturers about conducting similar non-standard impact tests on their products. Nothing has been scheduled, however.