A Comparison of the Legibility and Visibility of Enamel and Reflectorized 1971 Virginia License Plates

About the report:

The Safety Section of the Virginia Highway Research. Council carried out observation tests of the legibility and visibility of reflectorized and enamel license plates. The primary objectives were to determine the comparative legibility and visibility distances of these plates under low beam headlights and from several angles of approach. Fifteen subjects were selected from the civilian driving population and law enforcement agencies. Each was required to have a valid motor vehicle operators license and to pass a visual screening examination. License plates were mounted on the rear of a 1968 Chevrolet four door sedan. A 1970 Ford station wagon was used as the test vehicle. The same vehicles were used for each subject. Tests were carried out during favorable weather conditions, in a rural locale at night. For legibility tests the test vehicle started 200 feet from the stationary vehicle and proceeded until the subject could read all the digits without error. Visibility tests started 2,000 feet from the stationary vehicle and proceeded at a speed not in excess of 5 mph until either the license plate or car could be seen. Tests were performed at various angles of approach and at various lighting arrays. In each set of legibility tests, the reflectorized plate could be read at a greater distance than could a similar enamel plate. In each set of recognition visibility tests an individual was able to determine that a danger to his vehicle operation existed at a greater distance when the stationary vehicle he was approaching was equipped with a reflectorized license plate. In each set of point source visibility tests, the distance at which a subject could detect light coming from a stationary vehicle was significantly greater for an automobile equipped with reflectorized license plates.

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