Sponsors
Maryland State Highway Administration
Partners
Maryland State Highway Administration
AECOM
Overview
This paper presents development steps, results and the lessons learned from an application of a volume-delay functions-based dynamic network model on the Maryland Statewide Transportation Model (MSTM) project. The MSTM was developed to analyze traffic issues throughout the state including traffic in rural areas, freight movements and travel between the Baltimore and Washington Metropolitan areas. An issue facing the MSTM and other statewide models is how to account for the dynamic conditions of a large-scale network and to understand the impact of these conditions on trips which span multiple time periods. As a way of improving the understanding of daily network conditions but avoiding the problems of detailed data collection and validation, a proof of concept dynamic network model of MSTM is developed. The model is able to track individual travelers but does not simulate vehicle movements. Instead, an analytical approach is used where volume-delay functions are used to update link delays. The model is implemented using TRANSIMS Version 6 Router application. The model is validated against traffic counts and static assignment model (MSTM) results. The results show that the method used in this paper provides better estimates of dynamic traffic conditions, enables tracking the location of individual travelers, and allows for the rerouting of vehicles in anticipation of congested conditions, while avoiding the need for detailed intersection information. The method also allows for computation within a reasonable amount of time. The validation results, despite the proof-of-concept nature, are comparable with the static assignment results and consistent with observed data.
Related Documents
Report: Statewide Dynamic Traffic Routing for Transportation Planning: Maryland Case