Estimating Vehicle Stops at Undersaturated and Oversaturated Fixed-Time Signalized Intersections

State-of-the-practice models for estimation of the number of vehicle stops at signalized intersections are first reviewed, and then two approaches are introduced for the computation of the number of vehicle stops at undersaturated and oversaturated signalized intersections. The first approach uses a microscopic model that computes instantaneous partial and full stops for undersaturated and oversaturated conditions by using second-by-second speed measurements. This model, in particular, has been introduced in the INTEGRATION traffic simulation software. The second model is an analytical formulation derived from the proposed microscopic model that computes the number of vehicle stops for oversaturated approaches over a given analysis period. Finally, comparisons of the stop estimates produced by the two proposed models with estimates obtained from current state-of-the-practice analytical models demonstrate the validities of both models in their respective domains of application.