Experimental studies show that car drivers adjust their speed in curves so that maximum vehicle lateral accelerations (LAs) decrease at high speeds. This pattern of LAs is described by a new driver model that assumes drivers control a variable safety margin of perceived LA based on anticipated steering deviations. Compared with a minimum time-to-lane-crossing speed modulation strategy, the model, based on nonvisual cues, predicts extreme values of LA in curves decrease quadratically with speed, in accordance with experimental data obtained in a vehicle driven on a test track and in a motion-based driving simulator. Variations of model parameters can identify "normal" or "fast" driving styles on the test track. On the simulator, it was found that upper limits of LA decreased less steeply when the motion cueing system was deactivated, although drivers maintained a consistent driving style. This is seen, per the model, as an underestimation of curvilinear speed due to the lack of inertial stimuli.
Samenvatting