Closed-Course Study to Examine the Effect of Alcohol Impairment on a Driver’s Ability to Identify and Read Signs

Abstract

Because alcohol has been found to be the primary contributing factor in many wrong-way crash studies, researchers at Texas A&M Research Institute conducted a nighttime closed-course study to investigate the behaviors of alcohol-impaired drivers and determine their interpretations of various traffic control devices. Researchers found that alcohol-impaired drivers tended to look less to the left and right and more toward the pavement in front of the vehicle. In addition, researchers confirmed that alcohol-impaired drivers did not actively search the forward-facing scene as much as nonimpaired drivers. Instead, alcohol-impaired drivers concentrated their glances in a smaller area within the forward-facing scene. Researchers also confirmed that drivers at higher blood alcohol concentration levels took longer to locate signs and had to be closer to a sign before they could identify the sign background color and read the sign legend. In addition, alcohol-impaired drivers had to be closer to signs with flashing red LEDs around the border before they could read the legend compared with signs without flashing LEDs.