DEVELOPMENT OF PERFORMANCE SPECIFICATIONS FOR COLLISION AVOIDANCE SYSTEMS FOR LANE CHANGE, MERGING AND BACKING. TASK 2 INTERIM REPORT: FUNCTIONAL GOALS ESTABLISHMENT

This report determines the set of functional goals, i.e., those changes to the situation, which would help to eliminate the lane change, merge and backing crashes or decrease their frequency or severity. The functional goals include consideration of changes or additions to the vehicle and/or additions to the roadway infrastructure. They have been identified from an examination of crash events, appropriately classified, from the 1992 General Estimates System and Crashworthiness Data System. Significance of crash types is ranked by frequency of occurrence as well as by "fatal crash equivalents". In addition to the most basic goal of eliminating the "blind spot", significant crash avoidance opportunities can be realized by guarding against "fast closing" vehicles during lane change and merging. These "fast approach" collisions, though infrequent relative to the "blind spot" crashes, have relatively large "fatal crash equivalents". Similarly for backing collisions, significant reduction of "fatal crash equivalents" can be realized by guarding against vehicles in a crossing path trajectory relative to the backing vehicle. These functional goals translate into top level requirements for collision avoidance systems. These requirements are briefly discussed and their implications on several system design issues are noted. This report forms the basis for Task 4: Development of Preliminary Performance Specifications.