Seattle's transportation system reflects its hilly terrain, waterways, and rapid growth. The city is a major regional hub for highways, ferries, rail, bus service, aviation, and maritime freight, but congestion has long been a defining challenge.
**Roads and highways** - **Interstate 5** runs north-south through the city and is the main regional freeway spine. - **Interstate 90** connects Seattle eastward across Lake Washington. - **State Route 99** provides an important north-south corridor, including the SR 99 tunnel. - **State Route 520** connects Seattle to the Eastside across Lake Washington.
**Public transit** - **King County Metro** operates the city's main bus network. - **Sound Transit Link light rail** connects North Seattle, downtown, the University of Washington area, the Rainier Valley, Sea-Tac Airport, and other regional destinations, with continuing expansion. - **Sounder commuter rail** links Seattle with Tacoma, Everett, and intermediate communities. - **Seattle Streetcar** operates limited streetcar service. - **Washington State Ferries** and passenger ferry services connect Seattle with Bainbridge Island, Bremerton, Vashon Island, and other destinations through the regional system.
**Airports** - **Seattle-Tacoma International Airport (Sea-Tac)** is the region's main commercial airport, located south of the city. - **Boeing Field/King County International Airport** serves cargo, business aviation, and specialized aviation functions.
**Rail, port, and freight** - Seattle is served by **Amtrak** for intercity passenger rail. - The **Port of Seattle** supports major cargo, cruise, and maritime operations. - Freight rail remains important for port and industrial logistics.
**Bicycling, walking, and new mobility** - Seattle has expanded bike lanes, multi-use trails, and neighborhood greenways, though terrain can be challenging. - Popular corridors include the **Burke-Gilman Trail** and waterfront or park-adjacent paths. - Walking is common in denser districts, though steep grades and traffic can affect accessibility. - Taxis, rideshare services, carshare, and a growing network of **EV charging stations** are widely available.
Water crossings and bridge reliability are especially important to daily travel, as seen in the major civic impact of West Seattle Bridge disruptions in recent years.
