An Intervehicular Spacing Display for Improved Car-Following Performance

A driver's inability to detect small headway changes and small relative velocities is a primary reason for his poor car-following performance. This can be greatly improved if he is given information-headway and relative velocity-concerning the state of a lead car. This may be provided visually, tactually, or audibly. In the study reported, a control stick with a built-in kinesthetictactile display was tested in a car-following situation. Performances with this display were compared to those obtained when no aiding was used in a similar situation. Sizable reductions in velocity variance and headway variance were obtained for the aided case relative to the unaided case. These were obtained for headways of 23 feet at 30 mi/h and 33 feet at 40 mi/h. Thus, this display can be effectively used at short headways.