Preventing Single Unit Truck Rollovers When Impacting Concrete Median Barriers

Roadside safety barriers, such as w-beam, cable, and concrete barriers, are used to contain and redirect runoff the road vehicles. These barriers must meet safety guidelines, as recommended in the National Cooperative Highway Research Program (NCHRP) Report 350, before installation on US roadways. In this study, the safety performance of permanent concrete median barriers (CMB) is investigated. Specifically, their effectiveness in preventing Single Unit Trucks (SUTs) from rolling over and intruding into adjacent traffic areas is studied. Using LS-DYNA nonlinear finite element software, a finite element model of an SUT impacting a permanent CMB was created and validated against full-scale crash test results. Upon completing the validations, simulations were performed to study the effect of vehicle mass, closing speed, barrier height, barrier shape, and impact angle on CMB safety performance. The results showed that increases in vehicle mass, increases in closing speed, and increases in impact angle all increased the likelihood of the crash resulting in rollover. However, increase in the barrier height reduced the possibility of rollover outcome.