BRAESS: Braess Paradox Explorer
BRAESS demonstrates fixed-demand and elastic-demand user equilibrium on a small editable network.
Quick Start
- Click Load Braess Example.
- Click Solve both cases to compare the network with and without the candidate link.
- Switch between fixed demand and elastic demand to see how demand responds to higher cost.
- Click links or nodes in the network editor to inspect or change parameters.
Example Uses
- Classic paradox: keep fixed demand at 6 and compare candidate link off versus on.
- Elastic response: use the default elastic demand curve and compare equilibrium demand in both cases.
- Sensitivity: run a sweep and export the CSV for plotting or discussion.
Things To Notice
- The app uses a built-in preset and direct map editing; there is no CSV upload or sample-file workflow in the public app.
- This module is intended for small teaching examples, not city-scale assignment.
References
- Braess, D. (1968). Uber ein Paradoxon aus der Verkehrsplanung. Unternehmensforschung, 12(1), 258-268. https://doi.org/10.1007/BF01918335
- Braess, D., Nagurney, A., and Wakolbinger, T. (2005). On a Paradox of Traffic Planning. Transportation Science, 39(4), 446-450. https://doi.org/10.1287/trsc.1050.0127
- Levinson, D. (2026). Braess Explorer: Browser-only Braess paradox and elastic-demand model. Software. https://github.com/dlevinson/braess-js
- Liao, C.-F., Liu, H. X., and Levinson, D. M. (2009). Simulating Transportation for Realistic Engineering Education and Training: Engaging Undergraduate Students in Transportation Studies. Transportation Research Record, 2109, 12-21. https://doi.org/10.3141/2109-02
- Original STREET project: Simulating Transportation for Realistic Engineering Education and Training, University of Minnesota legacy project site. http://street.umn.edu