A new study has been released on the effectiveness of guardrail end terminal designs. The new study analyzes how the different designs absorb impact energy. The data was collected from the states of Ohio and Missouri. The University of Alabama at Birmingham (UAB) School of Engineering conducted the guardrail study. The purpose is to gather field data so that the performance of these guardrail designs can truly be evaluated. Guardrails are vital to roadside safety. Data was gathered from guardrail related vehicle accidents in Ohio from 2005-2013 and in Missouri from 2005-2014. The study used data over these eight years worth of crashes that resulted in severe injury or death and compared the different guardrail designs in each crash. In all, five different guardrail designs were evaluated. Guardrail end contact was deemed the most harmful event in these accidents.
The guardrail is designed to lessen the severity of a crash by absorbing the energy of impact and allowing the car to come to a stop safely. The car is not supposed to be directed back into the roadway. The old design of guardrail was a blunt-ended design that would act like a spear and tear into the car. The new design is a “W” shape beam that flattens or kinks to absorb energy and deflect it away from the vehicles.
The results show that the old design of guardrail was 1.36 times more likely to cause severe injury and 2.86 times more likely to produce a fatality than the new design. The research consists of a small sample size, and the researchers caution that there needs to be more research performed. Several new designs are available, and the numbers do not show which designs are most effective. What the research does show is that the new “W” shaped designs are far more effective and safe than the old blunt-ended designs.
The Safety Institute and The Center for Auto Safety intervened in a lawsuit under the False Claims Act dealing with this guardrail design. The suit alleges that the contractor changed the design of the guardrail, making it more unsafe, and failed to disclose this to the proper government authorities.