We consider the problem of choosing a subset of proposed road network upgrades to implement within a fixed budget in order to optimize the benefit in terms of vehicle hours travelled (VHT), and show how to render the solution of this problem more tractable by reducing the number of traffic assignment problems that must be solved. This technique is extended to develop a heuristic algorithm for finding a schedule of road upgrades over a planning period that maximizes the net present value of the resulting VHT reductions.

Keywords: traffic assignment problem, constrained optimization, network modelling, road upgrade scheduling

Source code

• Source code for user equilibrium traffic assignment, and

• models for scheduling road upgrades

This code is also available on GitHub.

Slides

• "Traffic Assignment and Road Network Upgrade Planning" slides for "Mesoscopic modelling of traffic networks" workshop.

Manuscript

• Stivala, A., Stuckey, P., & Wallace, M. (2011) Selecting and scheduling an optimal subset of road network upgrades. arXiv preprint arXiv:2204.10175.