Testing Wildfire Evacuation Strategies and Coordination Plans for Wildland-Urban Interface Communities in California

Research Team: Kenichi Soga (lead), Bingyu Zhao, Louise Comfort, Pengshun Li, and Paola Lorusso

UC Campus(es): UC Berkeley

Problem Statement: Wildfire evacuations are persistent challenges every year in California. Current strategies rely on standard, but static approaches. However, implementing these are likely to be problematic under rapidly moving fire conditions and fragile communications infrastructures in Wildlife-Urban Interface (WUI) communities. In addition, current evacuation plans frequently neglect the challenges of coordinating operations across administrative boundaries (e.g., multiple towns sharing one highway exit), and limited communications between different jurisdictions (e.g., overwhelmed radio channels, loss of cellular signals). And most small, resource-strapped residential communities in WUI zones do not have the capacity to conduct dedicated evacuation studies.

Project Description: In the event of a wildfire, government agencies need to make quick, well-informed decisions to safely evacuate people. Small communities, such as in Marin County, with a mix of residences and flammable vegetation in Wildland-Urban Interface zones tend to lack resources to conduct evacuation studies. Consequently, this study uses a framework of wildfire and traffic simulations to test the performance of potential evacuation strategies, including reducing the volume of evacuating vehicles through car-pooling, phasing evacuations by staggering evacuation times by zone, and prohibiting street parking in four representative areas of Marin County. Results show that reducing vehicle numbers lowers the average travel time by 20%-70% and average exposure time to wildfire by 27%-60% from the baseline. Phased evacuations with suitable time intervals lower the average travel time by 13.5%-70%, but may expose more vehicles to fire in some situations. Prohibiting street parking yields varying results due to different numbers of exits and evacuees. In some cases, prohibiting street parking reduces the average travel time by over 50%, while in other cases it only reduces the average travel time by 9%, contributing little to evacuation efficiency. Altogether, Marin County may want to consider developing a communication and parking plan to reduce the number of evacuating vehicles in wildfire situations. Phased evacuation is also highly recommended, but the suitable phasing interval depends on the speed of fire spread and number of evacuees. Further, whether to establish street parking prohibition policies for a certain area depends on the number of exits and the number of vehicles on the streets.

Status: Completed

Budget: $80,000