A decision model for gap acceptance and capacity at intersections

The purpose of this paper is to present a microscopic decision model for driver gap-acceptance behavior when waiting at an unsignalized intersection on the secondary road and also to estimate the resulting intersection capacity. The model is based on evaluation of the risk associated with not accepting small gaps against the potential benefit of their acceptance, which is the time saved as a result of shorter waits at the entry line. The model takes into account individual preferences by defining individual critical gap, which is different from the traditional macroscopic critical-gap approach. The latter estimates the critical gap for the entire population of drivers. The paper presents the difference between different driver populations (risk-loving vs. cautious) and shows how this difference actually results in different capacities on the minor road. (C) 2002 Elsevier Science Ltd. All rights reserved.