This document reports on a cooperative agreement between NHTSA and UMTRI entitled Intelligent Cruise Control (ICC) Field Operational Test (FOT). The main goal of the work is to characterize safety and comfort issues that are fundamental to human interactions with an automatic, but driver-supervised, headway-keeping system. Volumes I and II of this report describe the work done to prepare and instrument a fleet of 10 passenger cars with infrared ranging sensors, headway-control algorithms, and driver interface units as needed to provide an adaptive-cruise-control (ACC) functionality, and these volumes present results and findings deriving from operational testing lasting from July 1996 to September 1997. The vehicles were given to 108 volunteer drivers to use for two or five weeks as their personal cars. An extensive data base covering objective and subjective results has been assembled and analysed. The central finding presented here is that ACC is remarkably attractive to most drivers. The research indicates that, because ACC is so pleasing, people tend to utilize it over a broad range of conditions and to adopt tactics that prolong the time span of each continuous engagement. Notwithstanding having some concerns, field test participants were completely successful at operating ACC over some 35,000 miles of system engagement. In examining the results, the researchers observe that the role played by the driver as the supervisor of ACC entails subtle issues whose long-term safety and traffic impacts are unknown. These issues pertain to the shared control nature of ACC driving requiring a fine match to the perceptual and cognitive behaviour of drivers in a safety-central task that affects others driving nearby. Thus, while offering great promise for improving the quality of the driving experience, ACC implies an inherent necessity for human-centred design. Volume II of the report covers the operation of a serial string or dense cluster of passenger cars equipped with an ACC system (see separate documentation page in Volume III). (A)
Samenvatting