Daytime headlights and position on the highway. Paper presented at the Annual Meeting, American Academy of Optometry, Columbus, Ohio, 14 December 1964.

Photographic recordings of the position of oncoming automobile on the open highway in the daytime were made both with and without low beam headlights of displayed on the camera car. A speed of 55 mph was maintained on the two-lane U.S. Highway 37 north of Bloomington, Indiana. The positions of 1.127 vehicles were recorded. The oncoming cars occupied a narrower zone in their lane with fewer cars near the edge of the concrete as well as fewer near the center line when the camera car had its headlights on. It appears that the oncoming drivers were more alert when they faced approaching headlights in the daytime.