Automotive collision avoidance system field operational test methodology and results, volume 2: appendices

Abstract

The Automotive Collision Avoidance System field operational test (or ACAS FOT) project was led by General Motors (with Delphi playing a major supporting role) under a cooperative agreement with the U.S. Department of Transportation. The work conducted by the University of Michigan Transportation Research under this project is the subject of this two-volume report. This work involved developing the FOT methodology, gathering the FOT data, and the analysis and interpretation of this massive dataset. The FOT involved exposing a fleet of 11 ACAS-equipped Buick LeSabre passenger cars to 12 months of naturalistic driving by lay drivers from southeastern Michigan. The ACAS system included both a forward crash warning (FCW) system and an adaptive cruise control (ACC) system. The goal of the FOT was to examine the suitability of the ACAS system for widespread deployment from the perspectives of both driving safety and driver acceptance. Ninety-six drivers participated in the project, with an accumulation of 137,000 miles of driving. Data included over 300 data signals collected at 10 Hz with corresponding samples of video of the forward driving scene and the driver’s face. A set of subjective instruments were uses to capture information about the driver and their self-reported tendencies, as well as postdrive questionnaires, interviews (which included video replays of alert experiences), and focus groups. Results indicated that ACC was widely accepted by drivers, whereas the acceptance of FCW was mixed (due to false alarms) and was not found to be significantly related to FCW alert rate. ACC was found to be benign from a traffic safety perspective, with possible benefits resulting from the marked reduction in short (<1 second) headways and reduced passing behavior observed during ACC driving. While incidents were found in which the FCW may have contributed to a timely driver response to an emerging rear-end crash conflict, the frequency or magnitude of such conflicts in manual driving was unchanged when FCW was enabled. In addition, headways in manual driving with FCW enabled were found to increase on freeways and also during daytime driving.