Driving skills of young adults with developmental coordination disorder: regulating speed and coping with distraction.

In two experiments, we used an automatic car simulator to examine the steering control, speed regulation and response to hazards of young adults with developmental coordination disorder (DCD) and limited driving experience. In Experiment 1 participants either used the accelerator pedal to regulate their speed, or used the brake pedal when they needed to slow down from a pre-set speed. In Experiment 2, we introduced an auditory distraction condition that shared similarities with maintaining a conversation. Overall, the DCD group produced a larger variance in heading and needed more steering adjustments on straight roads, compared to age-matched controls. When turning bends, the DCD group showed greater difficulty in controlling steering while regulating their speed with the accelerator pedal but this was less problematic when using the brake. The DCD group also responded slower than the control group to pedestrians who walked towards their path. The auditory distraction in Experiment 2 had no visible effects on steering control but increased the reaction times to pedestrians in both groups. We discuss the results in terms of the visuomotor control in steering and the learning of optimal mappings between optic flow and vehicle control.