Transportation simulation and stakeholder exercises for urban seismic resilience

Earthquakes in the Central United States are low-frequency but high-consequence events that can increase evacuation demand while reducing transport capacity through bridge damage and precautionary closures. Municipal engineers and transport agencies therefore need planning methods that connect asset screening to corridor accessibility and coordination actions for the initial response period. This paper presents an integrated workflow for the St. Louis metropolitan region combining (i) earthquake-specific evacuation demand profiles derived from a household stated-response survey, benchmarked against a larger companion New Madrid Seismic Zone dataset, and embedded in a regional travel demand model; (ii) a USGS ShakeCast bridge screening for a Mw 6.7 scenario (3862 bridges analysed; 552 flagged for priority inspection); (iii) macroscopic and mesoscopic traffic simulation across 13 evacuation scenarios (earthquake timing, demand level and network status); and (iv) a multi-agency tabletop exercise (34 participants). Results show that a 07:00 event produces the largest demand surge and the deepest speed reductions on priority routes. Operating speed ratios identify MO-100, I-170 and US-67 as recurrent bottlenecks affecting emergency ingress and inspection logistics. The workflow yields transferable outputs: bridge and corridor prioritisation, congestion windows and coordination triggers for inclusion in municipal and state response plans.