Title: Road safety of passing maneuvers: A bivariate extreme value theory approach under non-stationary conditions
Authors: Ana Ferreira - IST-ID (Portugal) [presenting]
Abstract: Observed accidents have been the main resource for road safety analysis over the past decades. Although such reliance seems quite straightforward, the rare nature of these events has made safety difficult to assess, especially for new and innovative traffic treatments. Surrogate measures of safety have allowed to step away from traditional safety performance functions and analyze safety performance without relying on accident records. In recent years, the use of extreme value theory (EV) models in combination with surrogate measures to estimate accident probabilities has gained popularity within the safety community. We extend existing efforts on EV for accident probability estimation using two dependent surrogate measures. Using detailed trajectory data from a driving simulator, we model the joint probability of head-on and rear-end collisions in passing maneuvers. In the estimation, we account for driver-specific characteristics and road infrastructure variables. We show that accounting for these factors improves the head-on collision probability estimation. We also present an exploratory structure and results for combining surrogate measures that describe correlated events: in our case of passing maneuvers this considers the joint distribution of head-on and rear-end collision. Such a feature is essential to keep up with the expectations from surrogate safety measures for the integrated analysis of accident phenomena.