Enabling network-wide tolling-strategy assessment via customized route-choice simulation module

Tolling has been one of the most effective countermeasures against traffic congestion in metropolitan areas. Prior to the implementation of a tolling strategy, it was necessary to systematically evaluate the toll impacts on the transportation network. Microscopic simulation has been widely utilized as an evaluation tool in many traffic operation studies and practice. Most simulation tools on today's market, however, do not carry the functionality needed for customized toll-strategy assessment with the built-in modules. With the booming adoption of congestion pricing nationwide, it is highly desirable to enable simulation-based evaluation of various tolling strategies through external module development for widely-used simulation tools. This paper presents an innovative method for developing highly customized tolling strategy simulation through external routing modules compatible with a widely-used simulation tool. Using a publicly-available module, customized tolling schemes and routing algorithms can be implemented in the simulation tool. The method is demonstrated using the SR-520 toll bridge in Puget Sound as a test. The simulation results indicate that the developed module can effectively assess the impact of a variety of tolling schemes by determining travelers' routing decisions in real-time. The network-wide tolling impacts on link volume, travel speed, and emissions are evaluated in this study. The proposed method facilitates the understanding of key factors that would affect travelers' route choice and has great potential in tolling-strategy evaluation for transportation networks.