Issaquah study finds most neighborhoods can clear within about two hours; Highlands could take nearly three

An Issaquah emergency-management study presented June 16 found that under the modelled scenarios 90% of the city’s residents could leave Issaquah’s municipal boundaries in about 2 hours and 20 minutes, but Issaquah Highlands could take about 2 hours and 50 minutes to reach that same level of clearance.

Jared Schneider, Issaquah’s emergency manager, told the Committee of the Whole the evacuation time estimate (ETE) combines three factors: how long households take to start a trip, the amount of traffic generated during an evacuation, and the transportation network available to carry vehicles. “The wildfire evacuation time estimate study is really made up of 3 main factors,” Schneider said. The study used a community survey (more than 380 respondents) and a traffic simulation built from detailed roadway observations.

The nut graf: the study is intended to show how quickly people can exit city limits, not how long it takes to reach a designated safe shelter, and to help the city choose mitigation steps — from public outreach to physical infrastructure changes — that reduce evacuation time and avoid gridlock.

Key findings and immediate implications

- Citywide: the ETE for 90% of residents is about 2 hours 20 minutes under the study’s baseline conditions (mixed day/weekend and seasonal scenarios). Schneider said the study reports neighborhood-level times; “most of the neighborhoods individually … are somewhere around 2 hours to 2 hours 5 minutes.”

- Issaquah Highlands: Schneider said the Highlands is “by far our most challenging neighborhood to evacuate,” because of density and limited egress; its modeled 90% evacuation time stood out at about 2 hours 50 minutes.

- Traffic choke points: the study identified SR 900, East Lake Sammamish Parkway, parts of downtown near the I‑90 on‑ramp, and the Costco area as early congestion locations. Schneider noted roundabouts near city edges constrain evacuation flow because they limit safe travel speeds.

- Special populations and transport resources: the analysis included school pick‑ups, assisted‑living populations and the jail. Schneider reported the contractor estimated school transportation needs at roughly 10 buses (because most parents would pick up children), transit‑dependent needs at roughly 22 buses, and additional wheelchair buses and ambulances for medical/assisted‑living transport. The plan also accounted for a 13% “shadow evacuation” from nearby unincorporated areas and adjacent communities, which Schneider said equates to a substantial number of additional vehicles on regional routes.

Scenarios and potential long‑term fixes

Schneider described three modeled road‑building scenarios intended to reduce Highlands evacuation times: connecting Grand Ridge Drive to 220 2nd Avenue SE (modeled benefit ~35 minutes), a Northeast Natalie Way to Old Black Nugget Road link (~10 minutes), and extending to SE Issaquah‑Fall City Road (~30 minutes). He emphasized these are conceptual in the model and that environmental, ownership and feasibility questions remain.

Council members raised operational questions. Councilmember Chang asked how modeled flows would change if an evacuation required routing people away from a fire (for example, driving past a burning slope). Schneider said the baseline scenarios assume all modeled routes are available and acknowledged scenarios that block routes would likely be worse; the administration prioritized studying improvements that could make a measurable long‑term difference for the first set of scenarios.

Operational steps the city plans to take

- Exercise: the city will run a multi‑agency evacuation exercise applying the study’s findings; participants include Eastside Fire & Rescue, Issaquah School District, Costco and others.

- Variable (electronic) evacuation signs: Schneider and the City Administrator identified programmable signs as a key near‑term investment to direct traffic in real time and avoid sending evacuees toward blocked routes. The City Administrator said, “the variable signs… we are going to move expeditiously.” The administration indicated six candidate locations on city maps and said it may return with a budget request.

- School pickup planning: the study found school‑related pickup congestion can add roughly 15 minutes to some neighborhood evacuation times. One operational option cited by Schneider is directing parent pickups to specified collection points (for example, College Drive) to keep station areas and park areas clearer.

- Community outreach and preparedness: Schneider emphasized preparedness reduces travel times; the study’s community survey indicated most households said they would depart with one vehicle, and the city will promote consolidating vehicles, carpooling and signing up for Alert King County.

Next steps and timeline

Schneider said the city will pursue additional scenario development in the fall, develop a neighborhood story map for public use, scope electronic sign options this fall and, if feasible, install signs in winter. He said the study results will be used in a countywide community wildfire protection planning process now under way. The City Administrator committed to move forward “as quickly as possible” on signs and to return with an update in September or October.

Ending

Schneider and council members characterized the study as an operational tool to guide exercises, outreach and capital decisions rather than a set of finalized mandates. Schneider said the study showed both the limits of the road network as a capacity constraint and concrete near‑term actions the city can pursue to reduce evacuation time and improve coordination with regional partners.