Abstract
This simulator experiment is a preliminary study examining the effects of different auditory signals on braking force and reaction time in a rear-end collision warning system. A driving simulator was built in which subjects operated a computer driving game. Superimposed on the game screen was the image of a car which appeared to the driver to be ahead of him/her. The image enlarged in size, appearing to be a car applying its brakes. The participant was instructed to react as he would in a real driving situation by applying his/her brakes. Closing velocities of 10 miles per hour and 30 miles per hour were used. Braking times and forces were measured for four different warning sounds: 1) no warning; 2) a pulsed warning sound that increased in repetition rate; 3) a sound that increased in frequency; and, 4) a sound that increased in intensity. Results suggested that an auditory warning signal would decrease reaction time and increase maximum braking force applied. The sound that increased in frequency and the sound that increased in intensity provided the greatest savings in reaction time, approximately one quarter second, when compared to the no warning condition. The pulsed warning sound provided the greatest increase in braking force. Participants preferred the pulsed sound over the other warning sounds. Further research must be done to determine if the warning sounds decrease the reaction time enough to cause a significant reduction in accidents.
Hopkins, Jennifer Susan (1995). Use of an auditory signal in a rear-end collision warning system: effects on braking force and reaction time. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -H67.