Skip to Main Content
Concern about the effects of mobile telephone use on driving control led to the development of a methodology for evaluating driving performance. A summary of the methodology is presented along with the results of a study comparing the effects of dialing a telephone to the effects of adjusting the car radio. A detailed account of a study of the effects of alternative control unit designs is provided. Three types of dials were implemented for this study. They are a rotary dial, a pushbutton dial, and a pushbutton dial-in-handset. Three mounting locations for the pushbutton dial were studied: on the dashboard, in the dashboard, and in the visor area. The rotary dial and the dial-in-handset models were mounted on the transmission tunnel. The results of the study indicate that the design of a dial that is located within the reach and sight of the driver has little effect on driving control. User preferences favored a pushbutton dial mounted in the dashboard area.