Objective: This paper describes the results of the Honda-DRI ACAT-II program initiated by the National Highway Traffic Safety Administration (NHTSA) to develop test and evaluation procedures and methods to assess the safety benefits and effectiveness of advanced driver assistance technologies. 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.
Methods: 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 postconflict 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.
Results: 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 to be a 2.6% reduction in these types of crashes and a corresponding 11.3% reduction in fatalities based on simulation results. The overall benefits of the HCAAS, in terms of reduction in number of crashes and fatalities, when projected to the annual US level were estimated to be a 2,966 reduction in the number of US crashes and a corresponding reduction of 450 US fatalities per year. The results are based on various assumptions, approximations, and limitations that are summarized hereiZellner, JW, Van Auken, RM, Kelly, J, Silberling, JY, Hagoski, BK, Sugimoto, Y, “Advanced Crash Avoidance Technologies (ACAT) II Program – Final Report of the Honda-DRI Team, Volume I: Key Findings Report. Washington, DC: Honda and DRI for the National Highway Traffic Safety Administration; forthcoming. n and further documented in the supporting references, such as the representativeness and accuracy of the supporting data and reconstructed accident pre-crash scenarios.
Conclusions: Overall, this ACAT-II program was successful in extending and demonstrating a methodology that can be used to estimate the effectiveness and safety benefits and driver acceptance of frontal crash avoidance and mitigation countermeasures. The methods used are directly relevant to the test and evaluation procedures to assess the safety benefits and effectiveness of advanced driver assistance technologies.