Probabilistic Analysis ofHighway Capacity ManualDelay for Signalized Intersections

Abstract

is a new term in traffic capacity analysis, but it is routine in other areas of civil engineering. A probabilistic method, based on uncertainty and sensitivity analysis methods, to incorporate uncertainty of inputs into the existing Highway Capacity Manual deterministic delay model is proposed. Uncertainty analysis is the core of the probabilistic method for propagating the uncertainty of inputs into the uncertainty of the output. Sensitivity analysis is a supplement to uncertainty analysis to guide the data collection, refine uncertainty analysis, and help explain the results of uncertainty analysis. Results of the probabilistic method provide users with a comprehensive view of the level of service (LOS) of a signalized intersection that is more realistic and robust than that of the current method. A case study demonstrates the application of the proposed probabilistic method. With the proposed method, outputs change from a single delay value and LOS letter to mean value, standard ...