Extension of the Honda-DRI “Safety Impact Methodology” (SIM) for the NHTSA Advanced Crash Avoidance Technology (ACAT) II Program and Application to the Evaluation of a Pre-Production Head-On Crash Avoidance Assist System - Progress Report

This paper reports on the interim progress of the Honda-DRI ACAT-II program initiated by the National Highway Traffic Safety Administration (NHTSA). The objectives of the ACAT-II program were further development of a formalized Safety Impact Methodology (SIM) for estimating the capability of advanced technology applications installed in vehicles to address specific types of motor vehicle crashes, and to evaluate driver acceptance of the technologies. This particular ACAT study extended earlier work by Honda and DRI in the NHTSA ACAT-I program by extending the SIM so as to be able to analyze head-on crashes more completely, and by using the extended SIM to evaluate of a pre-production version of a Honda Head-on Crash Avoidance Assist System (HCAAS). More than 25 substantial SIM extensions and refinements were implemented, including: updated and extended FARS and NASS database extractions; improving the accident reconstruction process for NASS/CDS cases and developing a new special purpose reconstruction algorithm applicable to head-on cases with low lateral acceleration “drifts;” extending the driver-vehicle- ACAT environment simulation to include a post-conflict recovery phase; and further automating the overall safety benefits evaluation steps. The extended SIM and results from objective tests were used to evaluate the safety impact of Honda's pre-production H-CAAS based on a large number of simulations of a sample of reconstructed real-world head-on crashes. The effectiveness of the H-CAAS in reducing the number of two-vehicle “Same Trafficway, Opposite Direction” crashes (including non-H-CAAS technology relevant crashes) and fatalities if the H-CAAS were installed on one of the crash involved vehicles were estimated based on simulation results. The overall benefits of the H-CAAS, in terms of reduction in number of crashes and fatalities, when projected to the US level were also determined. Overall, this ACAT-II program was successful in extending a methodology that can be used to estimate the safety benefits and driver acceptance of frontal crash avoidance and mitigation countermeasures.