A simplified queue discharge flow model is commonly employed for estimating capacity and various performance statistics (delay, queue length, etc). This model uses a constant saturation flow rate and converts the displayed green time to an effective green time using start loss and end gain time parameters associated with the saturation flow rate. This paper describes the exponential queue discharge flow rate and speed models, and presents a summary of model calibration results based on data from 18 intersections in Melbourne and Sydney, Australia. Relationships among saturation headway and speed, jam spacing, queue departure response time, queue departure wave speed and acceleration characteristics are presented. Implications of the queue discharge flow and speed models for adaptive signal control practice, namely the SCA TS control parameters, optimum detector loop (detection zone) length and the gap setting parameter are discussed. (Author/publisher) For the covering entry of this conference, please see ITRD abstract No. E208120.
Samenvatting