A Survey of the Condition of Lighting Equipment on Vehicles in the United States

A nationwide survey was conducted of the condition of vehicle lighting equipment. Twenty different sites were visited and a total of nearly 1, 000 vehicles included in the sample. Headlamp aim and dirt levels were measured and the condition of marker and signal lamps noted.

The results of the survey indicate that many vehicles have headlamps that are badly aimed. The condition of front and rear marker and signal lamps is generally good, with more than 98% of such units functioning. Side marker lights were in poorer shape, hut more than 90% of these were operating. Consistent differences were found between areas with and without vehicle inspection programs. It appears that such programs are effective in improving the condition of vehicle lighting systems.