Extent and Effects of Handheld Cellular Telephone Use While Driving (SWUTC/01/167706-1)

This study accomplished three objectives: (1) collect and compare local law enforcement perceptions on drivers' use of cellular telephones to previous law enforcement focus group results; (2) develop field procedures and assess the magnitude of handheld cellular telephone use by drivers on freeways during the afternoon rush hour; and (3) investigate the relationship of conversation intensity and cellular telephone operating mode to driving performance.|Law enforcement personnel from several agencies in the Dallas/Fort Worth area were interviewed in March 2000. They indicated that drivers' cellular telephone use is increasing, and they have witnessed some of the detrimental effects. Failure to obey traffic signs and signals or maintaining lane position was noted. Road rage was even indicated to be a result of drivercellular telephone use. All those interviewed agreed that hands-free cellular telephone systems would be advantageous for drivers.|Handheld cellular telephone use among drivers varies by travel lane. The peak travel direction generally exhibited higher proportions of handheld cellular telephone use than the off-peak direction. A conservative estimate of drivers' handheld cellular telephone use on Dallas County freeways during the afternoon peak period is 1 in 20. This estimate does not include the use by drivers of handheld cellular telephones with hands-free adapters, or in-vehicle, installed hands-free cellular telephone systems.|When a driver chooses to use a cellular telephone, both the driving and the cellular telephone tasks demand the driver's limited attention. Using a state-of-the-art high-fidelity driving simulator, the effects of conversation intensity and mode of cellular telephone operation (handheld or hands-free) on driving performance were investigated. Comparisons of workload ratings revealed that handheld, high-intensity conversation was significantly different than the hands-free, low-intensity conversation. Overall, participants reported that using the cellular telephone while driving required more effort than simply driving.