Mitigating Risks of Potential Closure

Jefferson County Uses Ladris AI to Assess Evacuation Impact of Proposed Infrastructure Closure.

At a Glance


  • Proposed bridge closure coincided with region’s highest traffic flow and peak wildfire season.
  • Limited routes to/from major population centers.
  • Risk of highly intense heat from wildfire along major highway.


  • Historical analysis determined traffic patterns during proposed dates of closure.
  • Critical data showed major increase in total evacuation time and average trip time to nearest medical center.
  • County’s case to state officials highlighted compounding risks of a potentially catastrophic emergency scenario.

Compounding Risks of Emergency

Jefferson County, a large and geographically diverse county, stretches to the eastern and western borders of Washington State. It contains major population centers like Port Townsend, accessed by only two egress routes: the Hood Canal Bridge and U.S. Highway 101. State officials proposed closing the Hood Canal Bridge for maintenance over several weekends in July and August of 2023. The county’s department of emergency management expressed major concerns over this proposed timeframe, citing the height of wildfire risk and the bridge’s annual peak traffic flow during tourist season. With the bridge closed in an evacuation scenario, traffic from Port Townsend would be forced through Highway 101 into Olympic National Park where there could be a high risk of lethal heat during a wildfire.

Visual Simulations to Mitigate Emergencies

Using Ladris AI, Jefferson County Emergency Management (EM) accessed precise estimates of key traffic patterns in a simulated evacuation scenario showing the potential effects of the proposed bridge closure.


Analyzed Historic Data

Historic traffic analysis determined that many of the dates proposed for the bridge closure were among the top 20 busiest days of traffic flow across the Hood Canal Bridge. The July-August period would also close the bridge at peak season for wildfire risk.

Generated Precise Travel Time Estimates

Jefferson County EM used Ladris AI to model that the average trip time from Port Townsend to the nearest medical center would increase from 30 minutes to 2 hours with the bridge closed, and the total evacuation time would take 17-20 hours, versus 5-6 hours with the bridge open.

Mitigated Risks

State officials overturned the decision to close the Hood Canal Bridge during the dates originally proposed for maintenance. Informed by the expertise of the Jefferson County Emergency Management team, Ladris’ evacuation modeling program produced real world numbers that supported the state’s critical decision to mitigate the risks of unsafe evacuation routes caused by a bridge closure.

“The Ladris modeling software gave us an unprecedented ability to help state officials find the safest dates for a critical infrastructure project.”
Wilie Bence
Director, Jefferson County Department of Emergency Management

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