This paper is based upon the study of 36 drivers/participants. Each driver operated an instrumented vehicle that can be switched between manual and adaptive cruise control (ACC) operation. The drivers were selected according to an experimental design balanced for gender, age, and experience with conventional cruise control. Driving performance was measured in freeway operations. The variables measured include headway range, range rate. velocity, and acceleration/deceleration plus brake and accelerator pedal usage. The data have been processed to associate driver characteristics (age, gender, experience) with headway control performance measures. The results show that there is a wide range of manual driving characteristics. For example, the distributions of headway times (also called "available reaction times") for individual drivers are characterized by most likely values running from approximately 0.6 to 3.0 seconds. The paper discusses findings relating to measured driver characteristics, driver qualitative ratings, and specific properties of automatic headway control systems. (A)
Abstract