Do Drivers know they can Steer in the Dark?: An Empirical Test of the selective Degradation Hypothesis

Abstract

Drivers routinely overdrive their headlights at night. The selective degradation hypothesis predicts that drivers' overconfidence is a consequence of their ability to steer being preserved even though their ability to see details is impaired. This study investigated the extent to which drivers (18 to 78 years) understand that their ability to steer is preserved in low luminances. Participants estimated their ability to steer before driving a curvy, simulated roadway. Steering performance (but not acuity) was largely intact even in extremely low luminances. Particularly at lower luminances, however, drivers steered better than they had predicted. In the dimmest condition, participants drove outside their lane only 25% as often as they had predicted. These findings support the selective degradation hypothesis, help explain drivers' overconfidence at night, and reflect the fact that drivers do not understand that the ability to see details and the ability to steer are supported by separate neural mechanisms.