A properly designed guardrail must do more than simply prevent a vehicle from leaving the roadway. It must not deflect the striking vehicle back into traffic, or act as a ramp and send it airborne. A guardrail must deform in such a way that it allows the striking object to ride down the crash forces without undue harm.
ET-Plus Guardrails Implicated in Highway Injuries and Deaths
In May 2009, the driver of a 2003 Pontiac Vibe lost control of her vehicle on a Pennsylvania highway, striking the leading edge of a western berm guardrail. Instead of safely absorbing the force of the crash, the terminal end of this guardrail folded back, turning the end into a spear, which pierced the Vibe and pinned the driver. She sustained serious and permanent injuries.
The guardrail end terminal in this incident was a Trinity ET-Plus, a cheaper and less robust version of a product that had been installed along highways all over the world, and has performed in the field for years without controversy. The same cannot be said about the ET-Plus, however. Its performance has been tied to enough serious injuries and deaths to raise questions among state directors of Departments of Transportation and some engineers at the FHWA about its safety and is at the center of civil litigation or attorneys general complaints in several states. Documents also show that this new version of Trinity’s end terminal broke explicit Federal Highway Administration regulations in obtaining its place on the agency’s list of approved highway equipment. One state has already rejected this design.
… more state DOT’s are reviewing their use of these products each week. Let’s work together to get these failing end terminals off American highways.
David L. Kwass
The history of guardrail design is a search for a device that allows a vehicle to ride down the rail, and increase an occupant’s odds of survival without exacerbating the harm of a crash. The earliest types used exposed blunt ends that speared the vehicle in a crash, increasing its severity. In the mid-1960s engineers began evaluating the lethal consequences of these guard rail end designs, and by the 1970s developed the turned-down twist guardrail. This type of guardrail twists and buries the terminal ends in the ground. The design avoided the impaling problem, but caused vehicles to rollover instead.
In the last thirty years, highway officials have tried a variety of designs: Breakaway Cable Terminals (BCT), which were placed at an offset and featured posts designed to breakaway easily; the Crash Cushion Attenuating Terminal (CAT) and Breakmaster System, both of which absorb the crash energy, while. Slotted Rail Terminal (SRT)s designs cut longitudinal slots to allow the rail to buckle in a controlled manner, minimizing the yaw of the striking vehicle and the potential for intrusion into the passenger compartment. Today, the Energy Absorbing Terminal (EAT) is the preferred design – another type of attenuating terminal. During an impact, and EAT absorbs the crash energy, the head bends the beam 90 degrees, and extrudes the rail as a flat ribbon, and moves the rail away from the vehicle.
The ET-2000, manufactured by Trinity Industries Trinity Industries in a multi-billion dollar global industrial services and manufacturing corporation in the transportation, energy and construction sectors. It dominates the global guardrail market; its products have been installed on highways nationwide in the U.S. The ET-2000 is an EAT-type end terminal, installed in the early 1990s and developed by Dean Sicking, then a researcher at the Texas Transportation Institute at Texas A & M University. The ET-2000 reportedly had performed well in the field.
In 2000, the FHWA approved the first version of the ET-Plus, on the basis of one worst-case crash test, a head-on collision with a 2,000 kg pick-up truck at 60 mph. The ET-Plus reduced or omitted “non-structural elements,” making it 100 pounds lighter. It also differed from the original ET-2000 head in the size and shape of its face plate. Trinity only performed one of the seven required tests – the head-on with a pick-up truck at 60 mph. But, the FHWA agreed that performing the most severe test was sufficient to demonstrate acceptable performance of the modified extruder head. Since no other changes were made to the terminal anchor design, the agency permitted Trinity to forego the side impact tests
But, in 2002, Trinity began to make other modifications to the ET-Plus design. An unsealed federal whistleblower lawsuit alleges that Trinity reduced the height and length of the Feeder Chute Assembly – the location through which the W-beam is flattened and extruded. Shrinking these dimensions from 5 inches to 4 inches saved Trinity money by reducing its materials and assembly costs. The feeder channels could be inserted into the extruding throat, rather than being welded together, the lawsuit claims. In a crash, however, the reduced height created friction that interfered with the W beam’s ability to be properly extruded in a crash. Instead of safely ribboning out, the extruded beam folded back forming a spear that could penetrate the striking vehicle, according to the civil complaint filed by SPIG Industry, of Bristol, Va.
The Federal Highway Administration reimburses states for highway equipment, such as guardrails, that have been subjected to certain tests and approved by the federal agency. The rules regarding modifications to traffic safety equipment state that manufacturers must “certify to potential users that the hardware furnished has essentially the same chemistry, mechanical properties, and geometry as that submitted for acceptance.” Manufacturers must submit scaled drawing of safety devices, and subject them to a battery of tests. Trinity did not disclose the height reduction to the feeder chute to Trinity until 2012, when it came out in a patent dispute between SPIG Industry and Trinity.
In 2012, SPIG’s president Joshua Harman, informed the FHWA that his research into the design indicated that it had been modified in a way that was not reflected in the record on which its federal approval was based. This information touched off a controversy involving the manufacturer, the agency and state Departments of Transportation. In February of that year, Trinity finally informed the FHWA about the change to the 4-inch wide guide channels in the feeder chute, submitting drawings and crash tests reports prepared by the Texas Transportation Institute in May 2005. Trinity called it an inadvertent omission. By March 2012, Trinity submitted to the FHWA a 2011 letter stating that its ET-Plus with the 4-inch guide channels were crash tested in 2005.
In October 2012, the American Association of State Highway and Transportation Officials (AASHTO) sent its membership a brief, informal questionnaire concerning the field performance of the ET-Plus. Three of the 21 member agencies which responded stated that guard rail end terminals were involved in three severe crashes that caused serious injuries and deaths. Two members specifically referenced the ET-Plus. AASHTO requested that the FHWA review the crash acceptance of the ET‐Plus end terminal and document that the modified barrier system was sufficiently crashworthy.
The FHWA assured AASHTO that there was no “reliable data indicating that the ET-Plus end terminals are not performing as they were intended to perform,” and affirmed that the device was still eligible for reimbursement.
The agency took the same tack with journalists who pursued the story. In response to media inquiries, the FHWA has defended its decision to take no action against Trinity for failing to disclose the ET-Plus’s modifications at the time they were implemented and dismissed SPIG Industry’s allegations as simply a dispute between two competitors.
Internally, however, the agency has expressed concern. In 2012, a Nicholas Artimovich, a highway engineer, from the agency’s Office of Safety Technologies conceded to other agency engineers that there were “valid” questions about the ET-Plus’s field performance compared to that of earlier versions.
In an undated and unsent draft letter to Trinity — written after manufacturer had submitted its documentation in early 2012 — the FHWA observed that “..even though it appears that the ET-Plus terminal can still meet crash testing requirements, the number of highway crashes with fatal injuries involving the ETPLUS terminals does not match the excellent history of the original ET-2000 terminal.” The agency also took note that Trinity’s requests for approval made “no mention of one of the more visible differences between the older extruder heads and the ones you are currently selling.” It asked the company to submit drawings of the extruder head used in specific tests performed by TTI in 2005; the actual extruder head(s) used in the 2005 tests at TTl and the internal and external dimensions; and an in-service performance evaluation of the current Trinity extruder terminals.
In January, the State of Nevada notified Trinity that the ET-Plus would be removed from its approved equipment list, because it changed the size of the guide channels in 2005, without notifying the state Department of Transportation.
Trinity has defended its product, releasing a statement that says, in part:
Trinity stands by the ET-Plus® System, which we are proud to manufacture and sell. The false and misleading allegations being made were reviewed by the Federal Highway Administration, which re-affirmed its acceptance of the ET-Plus® System in October 2012. Further, the federal government has looked into these claims and declined to participate in a lawsuit. Trinity is pursuing the individual making these allegations aggressively in the courts and is taking all steps necessary to fully protect the intellectual property rights and the outstanding reputation of Trinity Highway Products and the ET-Plus® System.
In the meantime, the Trinity ET-Plus continues to be implicated in injuries and fatalities and defendants in civil lawsuits.