While writing this article, I received a video of a 1999 crash test conducted by the Texas Transportation Institute that shows how the barrier works. It’s called a terminal. You’ll recognize this section of barrier from the road, marked with yellow and black stripes. When a vehicle collides with a terminal, the barrier absorbs the energy of the impact by folding up like an accordion. The flat part at the front, called the end or head, slides along the barrier, helping to slow the vehicle. At the same time, the head pushes the barrier away from the vehicle so that it is a safe distance from the driver and passengers. You can see the metal barrier sliding out to the side during the braking process. The terminal manufacturer, Trinity Industries, is the subject of a lawsuit alleging that it changed the size of the barrier’s support members without notifying federal regulators. The changes saved the company about $2 per barrier head. But the lawsuit says the devices prevented the barrier from passing through the terminal properly. The result: Instead of pushing the metal barrier aside, the barrier threatened to cut the car.
       Concerns are growing about the safety of fencing sold by Trinity Industries as another state threatens to stop buying it and consider removing it.
       In a letter to Trinity on Friday, Virginia said state transportation officials believe Trinity failed to properly test the ends of the barriers it upgraded in 2005. Virginia officials also told Dallas-based Trinity that the company made design changes without their permission.
       Officials said if the company does not conduct new tests with Virginia officials and provide evidence to the state Department of Transportation by Oct. 24, the state will ban the products.
       ”We have given them a deadline to provide the studies we requested,” said Marshall Herman, a department spokesman. “If they cannot prove to us that this product is safe for use on Virginia roadways, we will not use it and we will begin an inventory of the locations where it is installed and consider removing it.”
       Trinity spokesman Jack Todd said the company “will fully cooperate and look forward to participating” in the state’s inspection of the fences. As for the VA’s findings, he said, “Trinity will be in direct contact with the agency to discuss and respond to their letter.”
       Last month, other states, including Missouri and Massachusetts, expressed growing concerns about the safety of Trinity’s fencing. In January of this year, Nevada banned sales of the product, citing Trinity’s improper disclosures. Now, the fencing, called ET-Plus, is the subject of a federal whistleblower lawsuit accusing Trinity of fraud. The lawsuit was heard Monday in Marshall, Texas.
       The dispute revolves around a design change Trinity made to the ET-Plus system in 2005. Some state regulators and federal lawsuits allege that the change could turn the guardrails into spears in a head-on collision. The changes were not disclosed to federal regulators for seven years, despite requirements that any such changes be reported immediately. Trinity is a major supplier of roadway guardrails in the U.S.
       The principle of the protective barrier is that in the event of a frontal collision with a vehicle, the barrier folds like an accordion, absorbing the impact of the vehicle and helping it to move backwards. In addition, a flat steel piece at the front of the barrier (called the “head”) slides along the metal barrier, pushing it aside and allowing it to be safely removed.
       Some government officials said Trinity’s redesigned product instead narrowed the channel behind the rail head, causing the rail head to stick instead of slide. When this happens, the rail head acts like a knife and pierces the vehicle, potentially injuring or even killing passengers.
       In a letter to Trinity on Friday, Virginia said state transportation officials believe Trinity failed to properly test the ends of barriers upgraded in 2005.
       The lawsuit alleges that the guardrails have caused at least 14 accidents nationwide, killing five people and injuring many more. According to internal Trinity documents, the change is expected to save the company $2 per track head.
       In May, Virginia sent Trinity questions about the barriers and asked for more crash-test documentation and ET-Plus charts. The state’s findings contradict those of the Federal Highway Administration. The Federal Highway Administration said it reviewed the 2012 crash-test results and concluded that the barriers were eligible for federal aid. The New York Times reported Monday that federal highway officials expressed skepticism about the barriers before making public assurances.
       ”We have no credible data to indicate that ET-Plus terminals are not functioning properly,” Tony Furst, the agency’s deputy administrator for safety, wrote in a January 2013 letter to a nonprofit group representing highway and transportation departments across the country.
       While states are ultimately responsible for road equipment, the federal agency plays a critical role because it provides guidance on which products are eligible for federal reimbursement.
       Last Friday, Mr. Furst issued a memo asking state transportation departments to provide information on ET-Plus’ performance.
       ”Based on the information we have, we will take all necessary steps to ensure the safety of our highways,” Transportation Department spokesman Brian Farber said Tuesday.
       Virginia Department of Transportation spokesman Herman said the state plans to make its own safety decisions independent of federal guarantees.
       ”Even if a product is on the federal government’s approved list, that doesn’t mean we want it on our list,” she said.
       The government has yet to determine how much of that sum is attributable to Trinity’s ET-Plus, a task it will have to undertake if the company fails to meet its demands by October 24.
       Trinity has faced mounting pressure in recent weeks, including from ABC’s 20/20, but the company said it had “full confidence in the effectiveness and integrity of the ET-Plus system.”
       In early September, a report released by the University of Alabama at Birmingham analyzed nearly a decade of accident data from states including Missouri and concluded that the ET-Plus trains were nearly three times more likely to cause death than the previous version.