Estimating Safety Benefits for the IVI Generation 0 Field Operational Tests 2001-01-2818

The U.S. Department of Transportation (USDOT) established the Intelligent Vehicle Initiative (IVI) Generation 0 Field Operational Tests (FOT) to demonstrate the effectiveness and encourage the deployment of intelligent vehicle safety systems (IVSS). This paper presents a methodology for estimating potential safety benefits of IVSS from such FOTs. The metric chosen is potential reduction in number of crashes resulting from widespread deployment of the IVSS. The methodology is based on the approach developed by the National Highway Traffic Safety Administration, Federal Highway Administration, and the Volpe National Transportation Systems Center. New features of the methodology include rigorous estimates of crash probabilities combining analytical models with FOT data and detailed investigation of the variability associated with benefits estimates.

Although millions of miles will be driven in the IVI Generation 0 FOTs, few crashes are anticipated. Thus, the proposed methodology cannot rely on analysis of crash data alone. Instead, the proposed methodology partitions all crashes according to the driving conflict preceding each crash. It then looks simultaneously for a reduction in either exposure to driving conflicts (exposure ratio) or chance of a crash after a driving conflict has occurred (prevention ratio). While estimating the exposure ratio depends only on the FOT data, estimating the prevention ratio involves both the FOT data and a modeling component. The modeling component considers driving conflict outcomes besides those observed in the FOT.