A new methodology is developed to estimate delay at uncongested stop-controlled intersections. It is based on dividing total delay into two distinct components - service delay and queue delay - and developing separate models for each component. Empirical models are developed to estimate the average service time and the variance of the service time as a function of the traffic volumes. Then, the estimated values are used as inputs to the theoretical queuing equations for average wait time to estimate the average queue delays. This idea is the key connection between the empirically estimated service time as well as the variance of service time with the theoretically estimated queue time. The M/G/1 and M/M/1 models are used to represent the queue delay at two-way and all-way stop-controlled intersections, respectively. The service delay models and the queue delay models are combined to get the total delay models. The proposed models are built based on 46 hours of field data. The models are validated using independent field data, and are compared to the HCM. The proposed models are very practical because they use only two input variables: the subject approach arrival rate and conflicting traffic volumes. (A)
Abstract