Reflecting Impacts of Systemwide Pricing Strategies in an Integrated Continuous-Time Prism-Constrained Activity-Travel Simulator of Demand and Supply

Pricing policies are increasingly being considered in urban areas around the world to better manage travel demand, mitigate adverse impacts of automobile travel, and raise financial resources for much needed infrastructure development. This paper demonstrates the feasibility of applying an integrated microsimulation model of activity-travel demand and dynamic traffic assignment for analyzing the impact of pricing policies on the entire range of activity-travel choices. The model system is based on a dynamic integration framework wherein the activity-travel simulator and the dynamic traffic assignment model communicate with one another along the continuous time axis so that trips are routed and simulated on the network as and when they are generated. This framework is applied to the analysis of a systemwide pricing policy for a small case study site to demonstrate how the model responds to various levels of pricing. A generalized travel time measure that accounts for the pricing effect and reflects population heterogeneity in values of time is used to simulate activity-travel choices, including both activity generation and destination choice, in a prism-constrained activity-travel simulation paradigm. Case study results show that trip lengths, travel time expenditures, and vehicle miles of travel are impacted to a greater degree than activity-trip rates and activity durations as a result of pricing policies. Measures of change output by the model are found to be consistent with elasticity estimates reported in the literature, suggesting that the model is able to reflect adjustments in activity-travel behavior in response to pricing policies.