Abstract
This study evaluated the legibility of license plates under field viewing conditions. The independent variables were: plate background luminance, legend luminance, glare, and subject age. The plates were mounted on the front and rear of a vehicle and the subjects were driven slowly past, pressing buttons to indicate legibility distance. The results indicate a general superiority for fully reflectorized plates, especially under conditions of glare. The older subjects, in particular, seemed to benefit from the highly reflective plates.