Abstract
This paper examines the introduction of the CITÉ plan (Phases 1 and 2), a major mobility project combining a light rail transit line with a restructured bus network in the Québec–Lévis region. Using the METROPOLIS2 dynamic traffic simulation framework, the study evaluates the project’s potential effects on mode choice, user welfare, traffic conditions, congestion, and vehicle emissions. The analysis compares a baseline scenario with a scenario incorporating the CITÉ network, based on the official project specifications released by the Caisse de dépôt et placement du Québec.
The simulation results indicate a modest but consistent shift from private car use toward public transit, with approximately 2,400 fewer car trips during the morning peak period, representing a decline of 0.93%. A clear majority of users are projected to benefit from the project, with more than 64% classified as winners. The modal shift is also associated with lower congestion levels, including a reduction of more than 2,200 hours in total time spent in congestion, as well as a slight decrease in vehicle-kilometers traveled.
Environmental outcomes are similarly positive. The results suggest reductions of about 1.5% to 2% in major pollutants, including CO₂, NOx, CO, and particulate matter (PM2.5).
Overall, the findings suggest that the CITÉ plan would generate small but robust improvements in mobility performance, user welfare, and environmental outcomes at the metropolitan scale. More broadly, the chapter illustrates how a dynamic traffic simulation framework can support the ex ante evaluation of large public transit investments in mid-sized urban regions.
Keywords: Rapid transit system, light rail transit, pollution, congestion, dynamic model, METROPOLIS2, Québec–Lévis
JEL Codes: R41, R42, C63
Abstract
This paper examines the potential impacts of major road infrastructure projects in Quebec City using the METROPOLIS1 dynamic traffic simulation framework. The analysis considers two large-scale projects: the construction of a new inter-river bridge (the so-called “third link”) between Quebec City and Lévis, and the proposed extension of the Pierre Laporte Bridge. The evaluation compares a baseline scenario with alternative infrastructure scenarios in order to assess their implications for traffic congestion and travel times.
Following a detailed calibration based on local traffic and network data, the model is used to simulate short-term equilibrium adjustments in route choice and congestion patterns. The results suggest that the third link may relieve traffic pressure along certain critical corridors, while generating heterogeneous effects across the network, with congestion decreasing in some areas and increasing in others. By contrast, the extension of the Pierre Laporte Bridge appears to produce more uniform reductions in travel times and congestion levels.
Keywords: METROPOLIS1, Road infrastructure, Dynamic traffic simulation, Congestion, Public policy, Quebec City.
JEL Codes: R40, R41