Interstate 705

Interstate 705

Interstate 705 is an auxiliary Interstate Highway in Tacoma, Washington, serving as a short spur between Interstate 5 and downtown Tacoma near the Thea Foss Waterway and the Tacoma Narrows Bridge. The route provides direct access to the University of Washington Tacoma, Tacoma Dome, Museum of Glass, Amtrak's Tacoma station, and the Washington State Ferries terminal area. It functions as a connector for regional traffic from Seattle and Olympia to Tacoma's central business district and waterfront attractions.

Route description

I-705 begins at a stack interchange with Interstate 5 near the Hilltop neighborhood and drops southeast toward downtown adjacent to Union Station, Tacoma Municipal Building, Fox Theater, and the Washington State History Museum. The freeway crosses the Thea Foss Waterway on a tied-arch bridge near the Union Station Railroad Bridge corridor and terminates at a junction with SR 7 and city streets that provide access to Pacific Avenue, the Foss Waterway Seaport, and the Tacoma Art Museum. Along its short length the route passes under and beside rail lines used by BNSF Railway, Sounder commuter rail, and Amtrak services, linking multimodal hubs such as the Tacoma Dome Station, Thea Foss Waterway ferry docks, and nearby Port of Tacoma facilities.

History

Plans for a downtown Tacoma freeway spur date to urban renewal discussions involving the Tacoma city government, the Washington State Department of Transportation, and federal agencies such as the United States Department of Transportation in the 1960s and 1970s influenced by interstate expansion after the Federal-Aid Highway Act of 1956. Community opposition and shifting priorities delayed construction until the 1980s when commitments from the Federal Highway Administration and state legislators allowed design and right-of-way work to proceed. The freeway opened in stages culminating in the formal designation in 1988 and was part of broader waterfront revitalization efforts tied to projects like the redevelopment of the Thea Foss Waterway and establishment of the University of Washington Tacoma campus. Subsequent improvements have involved collaboration with entities including the Tacoma-Pierce County Chamber of Commerce, Pierce Transit, and historic preservation groups focused on assets such as Union Station and the Old City Hall.

Exit list

The highway contains a limited number of grade-separated exits serving downtown Tacoma and waterfront destinations. Major connections include the southern interchange with Interstate 5 providing movements toward Seattle and Portland, a mid-route exit to local streets near Union Station and the Museum of Glass, and the northern termination connecting to SR 7 and arterial streets leading to Pacific Avenue and the Tacoma Dome. Signage and exit numbering conform to standards promoted by the American Association of State Highway and Transportation Officials and the Federal Highway Administration.

Future and planned improvements

Planned projects have emphasized multimodal access, seismic resilience, and waterfront integration driven by regional plans from Sound Transit, the Puget Sound Regional Council, and the Washington State Department of Transportation. Proposals include improved pedestrian and bicycle connections to Ruston Way, upgraded seismic retrofits near rail overpasses used by BNSF Railway and Amtrak, and streetscape enhancements coordinated with Tacoma's Downtown Waterfront Project and redevelopment initiatives led by the Port of Tacoma and City of Tacoma. Funding discussions have involved allocations from state transportation packages approved by the Washington State Legislature and federal discretionary grants from the U.S. Department of Transportation.

Design and engineering features

Engineering of the spur incorporated short-span bridge structures and retaining systems to traverse constrained urban right-of-way adjacent to historic buildings like Union Station and cultural institutions such as the Museum of Glass and Tacoma Art Museum. The alignment minimized relocations through use of cut-and-cover sections and viaducts, with stormwater treatment measures coordinated with the Thea Foss Waterway cleanup overseen by the Environmental Protection Agency. Lighting, drainage, and structural designs follow standards from the American Association of State Highway and Transportation Officials and seismic design criteria informed by the United States Geological Survey regional studies on the Cascadia subduction zone. Noise mitigation and landscaping have been implemented in collaboration with the City of Tacoma and local neighborhoods including Old Tacoma and Hilltop.

Category:Interstate Highways in Washington (state) Category:Transportation in Tacoma, Washington