IMPROVING ROADSIDE SAFETY BY COMPUTER SIMULATION

The overall level of safety provided along highways in this country has improved greatly over the last several decades. The clearest demonstration of this improvement in roadside safety is the continuing drop in fatality rates. Some portion of this reduction can be attributed to improvements in vehicle design and increased usage of occupant restraints; however, improved roadside safety design and features also contributed to the reduction. The clear zone concept is perhaps the most important contributor to roadside safety design. Based on this concept, roadside hazards are removed or relocated further from the traveled way whenever possible. When hazards cannot be removed or relocated, breakaway devices or protective safety features, such as traffic barriers and crash cushions, have been utilized to minimize the danger to motorists. However, a number of difficult problems remain to be solved in the continuing effort to improve roadside safety. Computer simulation of vehicular impacts using an advanced, nonlinear finite element code, such as DYNA3D, is the only practical alternative to full-scale crash testing for the large array of safety performance evaluations that are needed.