Understanding overdriving: Human factors considerations in heavy vehicle headlight visibility and stopping distance

Abstract

Nighttime road fatalities are a significant safety concern in the U.S., especially those involving commercial vehicles. Often an explanation offered involves overdriving headlights, or driving at a speed that does not allow for safe response within the range of the headlights’ visibility. The scientific literature was reviewed to assess the real-world applicability of guidance commonly provided in Commercial Driver’s License (CDL) manuals that advises heavy vehicle drivers to drive at a speed that allows them to be able to stop within the range of the vehicle’s headlights. We conclude that this guidance provided by CDL does not account for the variety of roadway types, driver expectations, and travel speeds, nor a scientific understanding about visual perception and hazard avoidance. It is recommended that further work be conducted to examine real-world application of commercial vehicle driver capabilities and variable roadway types to better inform guidance and recommendations.