Crash performance of X-shaped support base work zone temporary sign structures

Results from numerical analyses of temporary sign structure crash tests are compared with test data to assess both their crashworthiness and numerical model effectiveness. In addition, a parametric study is performed to investigate the influence of various parameters that would affect crash performance. Sign structures supported with an X-shaped base configuration in plan ('X-base') were examined, with all tests being performed following National Cooperative Highway Research Program (NCHRP) 350, 'Recommended Procedures for the Safety Performance Evaluation of Highway Features' guidelines [16]. Simulations and tests were completed at a speed of 98.7 km/h (61.3 mph) as directed by NCHRP 350 with the signs oriented perpendicular and parallel to the vehicle's direction of travel. Results from the study indicated that numerical simulations properly predicted the crash behaviour. In addition, both the numerical model and crash tests showed that orienting the X-base structure parallel to the vehicle direction would result in sign penetration into the vehicle compartment and, subsequently, an unsatisfactory condition according to NCHRP 350.