Beyond the Highway Capacity Manual Framework for Selecting Simulation Models in Traffic Operational Analyses

Simulation is often used to address issues that cannot be effectively resolved using the Highway Capacity Manual (HCM) or other analytical procedures. However, guidelines are not available for appropriate application of simulation as a complement or substitute for HCM procedures. The purpose of this paper is threefold: (a) to provide an overview of simulation models in a context consistent with facilities and situations addressed by the HCM, (b) to present a framework for the appropriate selection of simulation models when procedures of the HCM are not adequate, and (c) to provide brief examples demonstrating application of the proposed framework. The paper is divided into five sections. The first section presents simulation concepts and definitions. The second presents a suggested framework for application of simulation within an HCM context. The third and fourth sections apply this framework to the evaluation of uninterrupted- and interrupted-flow facilities, respectively. In these, appropriate application of the proposed framework for integration of simulation into an HCM-type analysis framework is presented. Last, the relationship between the methodological framework presented in this paper and the upcoming HCM 2000 is discussed.