On May 28, 1970, seven Seattle residents file suit in Federal Court to stop the construction of Interstate 90 through the Mount Baker neighborhood. The suit (Lathan v. Volpe) alleges that the U.S. Department of Transportation and the State Transportation Commission and the State Department of Transportation failed to follow the National Environmental Policy Act (NEPA), failed to hold proper hearings on the plan, and failed to provide for the relocation of displaced residents.
The project involved building a tunnel through Mount Baker and new bridges across Lake Washington. The plaintiffs prevailed in District Court and on appeal. After new environmental impact studies and design hearings, the court lifted its injunction against construction in 1979.
I-90 opened for traffic in 1992. Interstate 90 is the northernmost east-west highway in the Interstate Highway system. It connects to Interstate 5 just south of downtown, goes east across Lake Washington, across Mercer Island, past Issaquah and North Bend and over Snoqualmie Pass to Boston.