Abstract

Highways are comprised of tangent and curved sections. It has been established that there is a difference in safety between these types of sections. Roadside safety hardware, however, is not specifically designed or tested to address the differences in behavior that may be associated with placement of curves relative to tangent sections. The differences in safety performance may be negligible due to a host of intervening factors, but given little formal attention on this matter, that remains an open question at present. This effort stems from a crash into a barrier that occurred on a superelevated curve. It represents an attempt to determine if simulation tools can provide useful insights on the impact dynamics, influencing factors, and the likely outcomes. Simulation analyses were undertaken for three curvature conditions for NCHRP Report 350 crashworthiness criteria for the 2000P and 820S vehicles. Three types of concrete barriers were evaluated based upon NCHRP Report 350 metrics. The results suggest that adverse safety performance is more likely for the more highly sloped barriers when impacted on the sharper curves. The influences of various factors were analyzed and a criticality table was generated to indicate the effects of combination of factors for barriers on curved roads. The influence of vertical slope and superelevation were also considered to a limited degree.