The driver's ability to control the lateral position of an automobile is dependent on his perception of the command path (roadway) to be followed. This perception is affected by both the configuration of road markings and other features, and the visibility of these elements. As visibility decreases, the driver's preview of the commanded path is reduced.Theory indicates that driver performance should degrade with reduced preview and configurational parameters which characterize the intermittent nature of delineation (e.g., dashed lines). This paper describes a simulation experiment in which driver behavior and driver/vehicle system performance were measured over a range of visibility and configuration parameter variations. Driver dynamic response and noise (remnant) were reliably affected by variations in visibility and configuration. These effects were also reflected in system performance measures such as lane deviations. The results suggest minimum perceptual (visibility) requirements for the driver to maintain adequate steering control of a car under reduced visibility conditions.