Empirical Analyses Of The Effect Of Opposing Left-Turning And Leading Left-Turning Vehicles On Capacity Of Intersections With

Primarily, it investigated the effect of two conditions associated with dynamic sight distance problem. The conditions are (1) the presence of left-turning vehicles in the opposing lane and (2) non-compact vehicles leading smaller vehicles or vehicles of the same size leading in a left-turn queue. The critical gaps and follow-up times directly attributed to dynamic sight distance problem and without dynamic distance problem were determined empirically.

The results were used to determine the intersection capacity based on the Highway Capacity Manual's model for estimating potential capacity. The results show that dynamic sight distance problem increases critical gap and follow-up time, and also reduces capacity at intersections with unprotected left-turn movements. The empirical investigation concurs with results obtained from previous analytical investigation which concluded that the presence of moving vehicles along opposing left-turn lane and leading non-compact vehicles in a left-turn queue, two of the conditions associated with dynamic sight distance problem, increase the critical gap and follow-up time, and