Four Lakes to Idaho

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I-90 - Four Lakes to Idaho - Operational Study

Project background

Interstate 90 (I-90) in the Spokane area, constructed between 1958 and 1974, is increasingly experiencing regular congestion. This congestion occurs primarily during the morning and afternoon peak hours in a commute-directional manner. Non-recurring congestion outside of peak periods is also being seen more frequently. Both of these types of congestion contribute to crashes occurring on this corridor.

The Washington State Department of Transportation (WSDOT), through a programmatic screening process, analyzed highway segments statewide to identify those that have potential for safety improvements. Within the Spokane area, I-90 from the US 2 interchange to the Broadway interchange was identified as a high collision corridor segment. Funding for a safety improvement project was received for this section. In consideration of operational performance, the Eastern Region Traffic Office decided to expand the boundaries of the study to encompass the segment from the SR 904/Four Lakes Interchange to the Idaho State Line, as this is the primary urban core through Spokane.

WSDOT contracted with DKS Associates, an engineering firm, to assist us with performing a study focusing on improving safety and operations of the existing freeway through the expanded boundary limits. DKS will examine crash history and operational performance in closer detail and make recommendations for project strategies. This study will emphasize low cost strategies to efficiently move traffic on the existing system in a manner which improves safety and addresses transportation deficiencies, versus higher-cost capacity expansion strategies.

What's happening now

WSDOT Engineers and the consulting firm (DKS) are now analyzing traffic volume and collision data shown below. Following that analysis, the team will formulate potential low-cost strategies. Those strategies will be presented to the study advisory team and the public for review. The public is invited to comment on the study and/or ask questions by contacting Larry Frostad, Assistant traffic Engineer, WSDOT Eastern Region.

Study information and preliminary data


Larry Frostad, Assistant Traffic Engineer
WSDOT Eastern Region
2714 N. Mayfair
Spokane, WA 99207

I-90 Four Lakes To Idaho Locator Map