Determination of Capacity at All - Way Stop - Controlled ( Awsc ) Intersections

A new theoretical approach for the determination of capacities at All-Way Stop-Controlled intersections is presented. This approach is based on the Addition-Conflict-Flow method developed from the graph theory. The point of view related to the traffic streams in contrast to existing procedures, which handle only the approaches allows a systematic and realistic analysis of the traffic process at All-Way Stop-Controlled intersections. The new procedure can handle most common lane configurations in the real world. A simple and more practical procedure is then recommended. In practice, this simplified procedure can be used for single-lane approaches as well as approaches with separate left-turn traffic lanes. This procedure is verified and calibrated with measured data. For the calculation of the capacity at All-Way Stop-Controlled intersections, general parameters, which are found by calibration, are proposed. The procedure produce results more precise than the existing ones compared to the measured data. As a result, the maximum total capacities of All-Way Stop-Controlled intersections with singlelane approaches are found to be between 1500 and 1900 personal cars per hour. The total maximum capacities of All-Way Stop-Controlled intersections with single-lane approaches and separate left-turn lanes are between 1800 and 1950 personal cars per hour. Furthermore, it shows that the additional (left-turn) lanes significantly affect capacity increases only for asymmetric street-flow-splits. The present procedure can easily be extended to All-Way Stop-Controlled intersections with multilane approaches.