Project Profile: Lynnwood Link Light Rail Extension

The Lynnwood Link Extension is an 8.5-mile (13.7 km) light rail transit project designed to integrate Snohomish County into Seattle’s regional rapid transit system. This critical infrastructure addresses severe vehicular congestion along the Interstate 5 corridor by providing high-capacity, reliable electric light rail service. The project’s engineering scope included extensive elevated guideway construction, four state-of-the-art stations, and integration with existing transportation hubs.

Technical Specifications

The Lynnwood Link Extension alignment primarily follows the I-5 corridor, utilizing a mix of at-grade and elevated guideway structures to navigate complex urban terrain and minimize right-of-way acquisition. The line is double-tracked and electrified via a 1500V DC overhead catenary system. The four new stations—Shoreline South/148th, Shoreline North/185th, Mountlake Terrace, and Lynnwood City Center—feature elevated platforms, advanced passenger information systems, and multimodal integration points, including park-and-ride garages and bus transit centers. Station architecture incorporates innovative sustainable design, such as the Helical Sine Wave Trusses at the Shoreline South/148th station, engineered for efficient stormwater management. The service operates with Kinkisharyo Electric Railway Car rolling stock, configured in four-car consists capable of transporting approximately 800 passengers per train during peak headways of four to six minutes.

Key Takeaways

• Congestion Mitigation: The extension provides a direct, high-frequency alternative to the chronically congested I-5 corridor, projected to serve 63,000–74,000 daily riders by 2035 and reduce commute times between Lynnwood and downtown Seattle to under 30 minutes.
• Regional Economic Integration: By connecting Snohomish County’s primary population and employment center with the broader Puget Sound region, the project enhances labor mobility and stimulates economic development around its new station areas.
• Model for Transit-Oriented Development (TOD): The project’s station-area planning has catalyzed significant private and public investment in dense, mixed-use development, establishing a framework for sustainable urban growth in suburban corridors.

Frequently Asked Questions (FAQ)

When did the Lynnwood Link Extension open?
The Lynnwood Link Extension began full passenger service in late 2024, officially connecting Seattle’s Northgate station to the Lynnwood City Center Transit Center.

Who built the Lynnwood Link Extension?
The project was managed and delivered by the regional transit agency, Sound Transit. Major civil construction was executed by joint ventures, including a team of Skanska and Stacy and Witbeck (SSW) and another of Kiewit Infrastructure West Co. and Hoffman Construction Company.