Interstate 705 (Washington)

Interstate 705 (Washington) is an auxiliary Interstate Highway in Washington connecting downtown Tacoma with Interstate 5 and the Tacoma Dome Station. The short spur provides direct access to the Theater District, Port of Tacoma waterfront, and Tacoma Link corridor, serving commuters, freight traffic, and transit users in Pierce County.

Route description

I‑705 begins at an interchange near State Route 509 and the Foss Waterway in Tacoma, immediately adjacent to landmarks such as Museum of Glass, LeMay—America's Car Museum, Washington State History Museum, and Union Station. The freeway proceeds northward, crossing over or near Pacific Avenue, Commerce Street, and the Tacoma Dome Station transit hub, linking to SR 7 and providing ramps toward I‑5 northbound and southbound. The route includes viaduct segments, retaining walls, and collector–distributor lanes that interface with Tacoma surface streets and the Port of Tacoma access roads serving rail freight and regional shipping facilities. Traffic control along the corridor interacts with agencies including the Washington State Department of Transportation, Pierce Transit, and the Federal Highway Administration due to its role in intermodal connectivity.

History

Plans for an interstate spur to improve access between Downtown Tacoma and I‑5 date to urban renewal and highway planning efforts in the mid‑20th century involving entities such as the Urban Renewal Program and regional planning bodies like the Puget Sound Regional Council. The project advanced amid debates involving the Tacoma City Council, Pierce County officials, and federal highway funding priorities administered by the Federal Highway Administration and influenced by modal advocates including Amtrak, BNSF Railway, and local maritime interests at the Port of Tacoma. Construction in the 1980s incorporated design standards set by the American Association of State Highway and Transportation Officials and culminated with the designation of the freeway as an Interstate spur in 1988, coordinated with the Washington State Legislature and the American Association of State Highway and Transportation Officials. Subsequent improvements have intersected with redevelopment initiatives in the Theater District, Tacoma and transit expansions by Sound Transit and Pierce Transit.

Exit list

The short length of the route yields a compact exit list serving downtown access, transit, and port connections. Major interchanges connect with I‑5, SR 509, Pacific Avenue, Commerce Street, and ramps to the waterfront near the Foss Waterway. The exit numbering follows the Washington system coordinated by the Washington State Department of Transportation and includes ramps configured for both northbound and southbound movements to integrate with I‑5 mainline express and collector lanes. Adjacent surface streets linked by the exits connect to destinations such as Union Station, Tacoma Dome Station, and cultural venues like the Pantages Theater.

Future plans and improvements

Planning for the corridor considers seismic resilience in a region influenced by the Cascadia subduction zone and incorporates standards promoted by the Federal Emergency Management Agency and the Washington State Emergency Management Division. Proposed projects studied by Washington State Department of Transportation and regional partners include retrofit work on viaducts, improved multimodal connections with Sound Transit light rail extensions, enhancements to pedestrian and bicycle access linking to Thea Foss Waterway, and freight mobility upgrades that coordinate with Port of Tacoma master plans and BNSF Railway operations. Funding discussions have involved ballot measures and legislative appropriations influenced by the Puget Sound Regional Council and local jurisdictions such as the Tacoma City Council and Pierce County Council.

Traffic and usage statistics

Traffic volumes along the spur reflect a mix of commuter, transit, and freight patterns reported by the Washington State Department of Transportation through annual traffic counts and model runs used by the Puget Sound Regional Council. Peak weekday volumes concentrate around commuter hours with modal interactions at the Tacoma Dome Station and nearby transit centers operated by Pierce Transit and Sound Transit, while freight surges align with port operations at the Port of Tacoma and rail schedules for BNSF Railway and Union Pacific Railroad. Vehicle classification counts, congestion indices, and safety performance measures are monitored in coordination with the Federal Highway Administration and local agencies to prioritize maintenance and capacity projects.

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