Prevention of Tractor-Semitrailer Rollovers Effectiveness of Electronic Stability Control Systems

This study estimated the effectiveness of electronic stability control systems and roll stability control systems in preventing rollovers of heavy-truck tractor-semitrailers. The study combined hardware-in-the-loop simulation with the analysis of independent crash data sets. Engineering and statistical techniques were used to estimate the probable safety benefits of stability control technologies for five-axle tractor-semitrailers. The conventional approach for assessing the safety benefits of vehicle technologies was to analyze crash data sets containing data on the safety performance of vehicles equipped with the technology of interest. Because the deployment of the stability technologies for large trucks was in its infancy, national crash databases did not yet have a sufficient amount of factual data that could be directly linked to the performance of the technologies. Therefore a novel method of examining the potential benefits of these systems was used. This study focused on untripped vehicle rollovers in curves through the examination of crash scenarios that would be likely to benefit from the technologies; the probable effectiveness of each technology was estimated. The analysis in this study did not have the advantage of examining representative crash data sets that contained identifiable data from vehicles equipped with the technologies. Therefore, the analysis was based oil probable outcome estimates derived from hardware-in-the-loop simulation, field test experience, and expert panel assessment, and these methods were used to estimate the safety benefits from the national crash data population.