This report discussed the effects of driver fatigue as measured by a modified Greenshields Drivometer over a 1,200-mi Turnpike test run by a two-man team. The Drivometer data recorded every 15 min, include counts of steering wheel reversals, accelerator reversals, speed changes, brake applications, and time. Steering wheel reversal rates and speed change rates were recorded for extended periods throughout the trip on a minute-to-minute basis. A round-trip run was made from Ann Arbor, Mich., to Philadelphia, Pa., by the way of Route 1-94, Detroit-Toledo Expressway, Ohio Turnpike, Pennsylvania Turnpike, and the Schuylkill Expressway. The return trip was made two days after the drive to Philadelphia. During the trip east, the drivers changed regularly every 1 1/2 hr. and took rest stops of 1/2 hr. or more. The return trip was started at 4:30 p.m., so the drivers were somewhat tired and each man drove until he felt it unsafe to drive rather than changing on a fixed time basis. Rest stops were as short as possible. The results of this pilot run indicate that the Greenshields drivometer records the early effects of fatigue on the drivers behaviour as well as measuring other characteristics of the driver and variations of his environment. The results clearly demonstrate the different physical and psychological characteristics of the two participants and supports the hypothesis that rates of steering wheel reversals, accelerator reversals, and speed change are sensitive measures of driver attention, stress and fatigue. The information obtained in this pilot study is being used in planning a more elaborate research project on driver fatigue.
Abstract