An Assessment of the Need for Changes in Virginia Law Concerning Headlamp Usage

About the report:

An evaluation was made of the need for changes in Virginia law concerning headlamp usage during periods of dusk and dawn and at times of limited visibility. At the present time motorists are required to turn on the headlamps of their vehicles one-half hour after sunset and to leave them on until one-half hour before sunrise. In addition, headlamps are required whenever visibility at 1,524 m (500 ft.) is not adequate for driving. The analysis included a review of the pertinent literature, photometric measurements of the illumination available at dusk and dawn, and a survey of the headlamp usage laws of all states in the U. S. The review of the literature combined with the photometric measurements indicated that there should be difficulties in seeing and being seen during the dusk/dawn period. The survey of headlamp usage laws indicated that 66% of the states had the same requirements as Virginia for the dusk/dawn period while 54% had the same requirements for usage under conditions of limited visibility. However, the survey suggested precedents for changes in the Virginia laws. Based on these results it is suggested that the following changes in headlamp usage be made: 1) headlamps be turned on at visible sunset and be left on until visible sunrise; and 2) headlamps be turned on whenever there is precipitation (rain, snow, etc.) or when visibility is not adequate for 1,524 m (500 ft.). It is felt that these changes should improve the ability of the motorist to see and to be seen and thereby contribute to highway safety.

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