Assessing Traffic Network Resilience Using Agent-Based Modeling and Simulation

Abstract

Urban areas are seeing influx of population and therefore are experiencing increasing stress on the systems currently in place. In traffic networks, a larger population means that their are inevitably a short term increase in mobility demands. To accommodate this, governments and and the private sector are proposing new solutions for mobility. One such focus is the introduction of new transport modes. A common classification for these modes is Mobility-as-a-Service (MaaS), which includes modes such as carsharing, shared last-mile transportation like bicycles, and ridesharing. MaaS also overlaps with other new modes such as autonomous and electric vehicles. Modeling these types of modes and their subsequent interactions with each other and traditional modes requires more complex modeling techniques than have been traditionally used in transport modeling.

The purpose of this thesis is to propose a method for using agent-based modeling and simulation (ABMS) to assess traffic network resilience, as ABMS has the dynamic qualities that match well with the time variant nature resilience.. This gap is especially prevalent when considering novel modes of transport, such as ridesharing. Data from the metropolitan region of Rotterdam and The Hague (Metropoolregio Rotterdam Den Haag or MRDH) is used for a case study on the corridor between Rotterdam and The Hague. The goal is to prove feasibility of a method for assessing resilience in traffic networks using ABMS.

A resilience framework for urban mobility is proposed that uses six categories to characterize resilience: (1) reflective, redundant, flexible, resourceful, inclusive, and integrated. Using this framework as a guide, three metrics are proposed for measuring resilience using agent-based simulation: origin-destination (OD) travel time, link travel time, and link volume. These metrics are used to compare scenarios that either include a disturbance in the network or do not, which in this case occurs for a 30 minute period on the A4 roadway between Rotterdam and The Hague. While the OD travel time metric is limited in its usability, the link travel time metric makes apparent the the recovery time to achieve normal operating conditions after a disturbance. In the presented case study, scenarios that included ridesharing had worse recovery time then the car only scenario, as well as a higher maximum travel time across the disturbed link. The link volume metric contextualizes these results, showing that while the overall volume throughout the simulation is lower for the ridesharing cases, the volume during the disturbance across the disrupted portion of the A4 roadway is higher. The higher volume shows why the travel time is higher with the presence of ridesharing in the disturbance scenario. These results are subject to the limitations of the model, though, which include dynamic routing that may not avoid the disturbed portion of the network when the disturbance occurs.