A mathematical analysis of the 2023 Lahaina wildfire proves that simply reversing one lane of traffic would have reached the town's absolute theoretical speed limit for evacuation.
April 1, 2026
Original Paper
Macroscopic Traffic Flow Network Modeling For Wildfire Evacuation: A Game-Theoretic Junction Optimization Approach with Application to Lahaina Fire
arXiv · 2603.29055
AI-generated illustration
The Takeaway
By modeling traffic like a flowing liquid, researchers discovered a 'phase transition' where adding more exit lanes eventually stops helping people escape faster. They found that for Lahaina, a simple lane reversal would have hit this mathematical limit, meaning even a massive four-lane highway wouldn't have cleared the town any faster than the existing road could have.
From the abstract
The 2023 Lahaina wildfire killed 101 people on a peninsula served by a single two-lane highway, making exit lane capacity the binding constraint on evacuation time. We model the evacuation as a system of hyperbolic scalar conservation laws on a directed graph with game-theoretic junction conditions that maximize total network flux, an evacuation-calibrated piecewise linear-quadratic flux function, and a loss-driven optimization framework that tunes traffic distribution toward priority corridors.