An evaluation of fundamental driver decisions and reactions at an intersection. Paper presented at the 44th Annual Meeting of the Highway Research Board, Washington, D.C., January 11-15, 1965.

Field measurement and analysis of fundamental driver decision and reaction parameters at a stop-signed intersection are reported. The following research objectives were pursued' /1/ a detailed examination to determine and verify the characteristics of lag and gap acceptance of drivers waiting at a stop sign, /2/ evaluation of the influence of the following traffic factors on driver decisions' vehicle type, pressure of traffic demand, direction of movements through the intersection, sequence of gap formation, and conditions on the opposing side street approach, and /3/ determination of the characteristics of starting delay time in accepting lags and gaps, and evaluation of the influence of certain traffic factors on these distributions. The results supported earlier findings which indicated the relationship between lag or gap size and percent acceptance is log-normal. Traffic factors studied which significantly influenced driver decisions were pressure of traffic demand, direction of traffic movement during periods of heavy demand, and sequence of gap formation during periods of heavy demand. These factors had similar and significant effects on starting delay times.