Warranting fixed roadway lighting from a consideration of driver work load. Paper presented at the 53rd Annual Meeting of the Highway Research Board HRB, Washington, D.C., January 1974.

Warranting conditions for fixed roadway lighting are determined. It is premised that the driver's visual work load can be considered in terms of the need for information and the supply of that information expressed in units of time. When demand time exceeds supply time without lighting, then lighting is warranted. Formulas for the necessary computations are presented.