Design optimization of a new W-beam guardrail for enhanced highway safety performance

As one of the most widely used safety devices on highways, W-beam guardrail plays an important role in protecting errant vehicles from entering dangerous zones or colliding with oncoming vehicles. As one of the most widely used safety devices on highways, W-beam guardrails play an important role in protecting errant vehicles from entering dangerous zones or colliding with oncoming vehicles. One common issue with the traditional W-beam guardrails (TWG) is tire snagging which often occurred when the wheel of a striking vehicle entangled with a guardrail post. Tire snagging reduces the redirection performance of the guardrail and can result in serious injuries to the occupants. In this study, a new W-beam guardrail, named as “η-shaped W-beam guardrail (η-WG)”, was developed using nonlinear finite element simulations combined with metamodeling-based design optimization methodology. The simulation results showed that tire snagging did not occur on the η-WG and the optimum design of the η-WG had an improved safety performance in vehicular crashes.