Safety impact methodology (SIM): evaluation of pre-production systems

This paper describes a basic framework for Safety Impact Methodologies (SIM) to estimate potential safety benefits of pre-production advanced Driver Assistance Systems (DAS). A common flow-chart, showing the interaction between data usage, crash scenarios development, model development, testing, data generation, and benefits estimation activities, is used to describe the basic framework. Although the framework applies to all types of evaluation of DAS, this paper focuses on those aspects that support evaluation of pre-production systems. The paper then describes three approaches to implementing the SIM framework for pre-production systems. Two of these approaches describe effectiveness in terms of reduction in number of crashes with the system active. The third approach describes the effectiveness in terms of fatality and injury reduction, rather than estimating crashes avoided. The paper concludes with descriptions of how the three approaches are being implemented in the SIMs that are being developed by the four teams participating in NHTSA’s Advanced Crash Avoidance Technology (ACAT) program. The paper also includes brief descriptions of other benefits evaluations as a means of highlighting how the framework accommodates evaluation of production systems and near-production systems as well as pre- production systems. The framework developed in this paper provides a cornerstone for development of safety impact methodologies for evaluating pre-production driver assistance systems and for comparisons of methodologies that are used to evaluate production and near-production systems. INTRODUCTION The automotive industry has made significant progress in the development of advanced technologies intended to prevent crashes and their consequences. Advanced technologies that include sensing, computing, positioning, and communications appear to have the ability to help drivers avoid imminent crashes or events that often lead to crashes and to reduce the severity of crashes that do occur. For example, some of these technologies address goals such as preventing rollovers, improving visibility, reducing tailgating, and reducing speed for safety related conflict conditions. A key question about these technologies is how effective they will be in preventing crashes and reducing the severity of injuries to vehicle occupants. To answer this question NHTSA initiated the ACAT program to determine if there is a methodology, or one can be developed, that will effectively measure the link between technological performance of pre- production systems and their safety impact. Benefits estimates from such a methodology can be used in many ways: 1) as part of the design process of new systems, 2) to evaluate the performance of pre- production systems before marketing, 3) to provide guidance to safety advocates, such as NHTSA, on new safety improvements, and 4) to form the basis for regulatory evaluations of potential new requirements. Methodologies that have been used for estimating safety benefits include: 1. Gathering crash data for systems that have been available to consumers for sufficient time to establish a record of numbers of crashes. This is a common method for evaluating the impact of new requirements in Federal safety standards.