A STATISTICAL ANALYSIS OF VEHICLE ROLLOVER PROPENSITY AND VEHICLE STABILITY. IN: OCCUPANT AND VEHICLE RESPONSES IN ROLLOVERS

Abstract

This chapter on the statistical analysis of vehicle rollover propensity and vehicle stability is from a comprehensive textbook on occupant and vehicle responses in rollovers. The author documents the accident data collection, processing, and analysis methodology used by the National Highway Traffic Safety Administration (NHTSA) in a major agency investigation of the rollover propensity of light duty vehicles. These efforts were initiated in response to two petitions for rulemaking requesting the development of a standard for rollover stability. Logistic regression models were used to investigate the ability of a number of stability measures to predict vehicle rollover propensity, while accounting for a number of driver and environmental factors. The results demonstrate the existence of a relationship between measures of roll stability and a vehicle's propensity to roll over in real-world single-vehicle accidents. Of the three basic roll stability metrics evaluated (tilt table ratio, static stability factor, and side pull ratio), the tilt table ratio appeared to provide the greatest explanatory power, but only by a slight margin over the static stability factor.