September 26, 2014
In the wake of a study on the safety of energy-absorbing guardrail end treatments sponsored by The Safety Institute, Missouri and Massachusetts DOT officials have announced that they will no longer consider the ET-Plus, manufactured by Trinity Industries, as approved highway safety equipment and are dropping the design from current and future construction projects.
Last Thursday, The Safety Institute released In-Service Evaluation of FHWA-Accepted Guardrail Terminals, conducted by the University of Alabama at Birmingham (UAB) School of Engineering, which examined eight years of severe injury and death data for crashes that occurred in Missouri and Ohio involving five different guardrail end terminal designs. While the data are limited, the study found that the ET-Plus design, manufactured by Trinity Industries, Inc., was 1.36 times more likely to produce a severe injury and 2.86 times more likely to produce a fatality than the ET-2000 design.
The TSI study, analyzed single-vehicle ran-off-road crashes that occurred in Ohio, between 2005 and 2013, and Missouri, between 2005 and 2014, in which contact with the guardrail end was identified as the Most Harmful Event. The Safety Institute initiated the study to gather objective performance data for the ET-Plus, which has been at the center of a controversy for two years.
“Our internal observations, as well as our review of available information, indicates to us that ET-Plus guardrail end treatment is not performing as intended and could pose the risk of malfunctioning,” said MoDOT spokesman Holly Dentner. “Therefore, we are taking proactive steps to correct the situation. We are immediately stopping the further use of this product on Missouri’s highway system by taking it off of our approved products list, removing it from projects currently under construction and prohibiting its use on any future projects.”
In a statement, Massachusetts DOT said: “In light of a recent report raising questions about the performance of a specific guardrail end terminal, MassDOT has taken initial steps to halt the use of that end terminal while the agency conducts additional research…if necessary, [it] will evaluate possible measures to repair or replace these end terminals already in use.”
In January, the Nevada Department of Transportation became the first state to reject Trinity’s ET-Plus. The Nevada DOT informed Trinity that its ET-Plus terminal would no longer be considered approved equipment, after it was revealed that Trinity had made a modification to the original design in 2005, without disclosing it to the Federal Highway Administration, as required.
Other states are investigating the possibility of following suit.
State transportation officials began raising questions about the safety of ET-Plus energy-absorbing end terminals, after Joshua Harman, the president of a competitor company, alleged that in 2005, the manufacturer made a design change to the ET-Plus, allegedly to save material and manufacturing costs, that affected its performance in a crash.
Guardrail impact attenuating end terminals are designed to lessen the severity of a crash, by allowing the striking vehicle to ride down the crash forces safely, without deflecting the vehicle back onto the roadway. Today, the W-Beam guardrail with an impact attenuating end is the most commonly used energy absorption barrier system. In this design, the end terminal rail is deformed away from the striking vehicle, either by flattening, cutting or kinking the rail. In the early 1990s, Trinity launched the ET-2000, an Energy Absorbing Terminal, which absorbs the kinetic energy of the striking vehicle, while bending the post away from it, and extruding the beam into a flattened ribbon.
In 1999, Trinity introduced the ET-Plus. Critics allege that the newer versions bear a dimensional change to the feeder chute, through which the rail is extruded. With this change the end terminal no longer performs like those of the earlier design. Instead of bending away, the rail jams in the chute, causing it to fold in half, forming a spear that can penetrate the striking vehicle, they allege.
Harman took his concerns to the Federal Highway Administration, the media and state departments of transportation. In the fall of 2012, three members of the American Association of State Highway and Transportation Officials (AASHTO) responded to a survey about the field performance of guardrail terminals indicating that the end terminals were involved in three severe vehicle crashes that resulted in serious injuries and deaths; two of the three agencies specifically referenced the ET‐Plus. AASHTO asked the FHWA to re-review its approval of the ET-Plus and document the modified barrier system’s crashworthiness under the federal criteria, NCHRP 350.
Emails show that other state DOT officials were nervous about the implications of Harman’s allegations and turned to the FHWA for assurance.
In a February 2012 email to the South Carolina DOT, Nicholas Armitovich II, a highway engineer in the FHWA’s Office of Safety Technologies conceded that there were “valid questions” about the ET-Plus’s performance.
On October 1, 2012 after speaking with Harman, Keith Cota, chairman of AASHTO’s Technical Committee on Roadside Safety and chief project manager for the New Hampshire DOT also wrote to Artimovich raising concerns about Harmans’ claims:
The question I do have is, “for the terminal units we are installing in NH, should it be providing a 5 inch feed channel or not?” We have many, many of these terminal units on our high speed facilities and this certainly causes me some strong concern for crash worthiness of the ET-Plus and ET-2000 that we have and are installing each year. I am not sure if I want to wait until the court case is decided and all the appeals have been completed to take action (20 years from now) or be ready to answer the next set of bigger questions as to 1) the need to retrofit the devices installed along our highway system and 2) who pays? I understand this has been going around for some time and I am just now becoming aware of the issues through the complainant in the lawsuit. I will be looking toward Nick to give some guidance as to how NH and other States should proceed. Should I be worried? Should I send this out to the full slot of TCRS State members? Or worst yet, should I brief my Chief Engineer? I don't like the box this puts me in!
Three months ago, a Dayton, Ohio couple was severely injured on I-93 in New Hampshire, when their Subaru Impreza struck an ET-Plus guardrail, which penetrated the occupant compartment at the passenger side wheel well, slicing the driver and the passenger in the legs and knees.
State departments of transportation buy highway safety equipment from a list of vendors whose products have been crash-tested and approved by the Federal Highway Administration; the FHWA reimburses states that use approved equipment. States rely on FHWA certification as an indication that the equipment performs adequately. The FHWA sought to quell the anxiety by asking Trinity to provide evidence that the design change was insignificant. Trinity sent photos of tests it said that it performed in 2005. The federal agency brushed aside the questions as a dispute between business competitors, and declared itself satisfied.
Clearly, the states are not.