Sound Transit Express
Express bus system in Seattle, Washington
Sound Transit Express (ST Express) is a network of regional express buses operated by the multi-county transit agency Sound Transit. The routes connect major regional hubs throughout 53 cities in three counties (King, Pierce, and Snohomish) in the Puget Sound region. Sound Transit Express ranks first in the nation in the number of commuter bus passengers carried and in vehicle miles driven. The first nine routes and 114 buses began carrying passengers on September 19, 1999. In 2025, the system had a ridership of 9,809,600, or about 25,600 per weekday as of the second quarter of 2026.
Unlike a typical transit bus service, Sound Transit Express routes typically make limited stops as they travel longer distances on the freeways. Most routes operate seven days a week, with runs throughout the day. Where available, buses use transit-only lanes, high-occupancy vehicle lanes, high-occupancy toll lanes, express lanes, bus bypass shoulders, and direct access ramps to speed travel times. The enabling legislation for Sound Transit requires the eventual replacement of interim express bus routes with forms of high-capacity transit, including Link light rail and bus rapid transit. As a result, many routes have been truncated or discontinued to accommodate expansions of the regional transit system.
While Sound Transit oversees, plans, and funds the service, operation and maintenance of the buses is contracted out to Community Transit, King County Metro and Pierce Transit. There are 240 buses in the system's fleet.
01Fares
ST Express uses a flat fare system, where each ride costs the same regardless of distance.
The fares are as follows:
| Fare type | All | |
|---|---|---|
| Adult | $3.00 | |
| Senior (65+) / Disabled / Medicare (Regional Reduced Fare Permit required) | $1.00 | |
| Low-income (ORCA LIFT card required) |
$1.00 | |
| Youth (6-18 years) | Free | |
| Children (0-5 years, with fare paying passenger) | Free | |
Paper transfers are not accepted or issued on Sound Transit routes. Passengers who use ORCA may transfer between ST routes or routes operated by most other agencies within two hours of initial payment. If the fare for the second route is higher, the difference will be charged.
Sound Transit reduced the base fare to match the Link light rail's flat $3 fare in March 2025.
02Routes
25 Sound Transit Express bus routes are overseen by the agency. Buses are operated under contract by King County Metro, Pierce Transit and Community Transit. When Sound Transit implements a new bus route, changes are frequently made to existing routes that serve the area to avoid overlapping.
The ST Express routes and operators as of August 2026 are:
| Route | Off-peak service | Weekend service | Start | Via | End | Operator |
|---|---|---|---|---|---|---|
| 510 | No (use route 512) |
No (use route 512) |
Downtown Seattle | I-5, South Everett Freeway Station, Mountlake Terrace Freeway Station | Everett Station
Downtown Everett (select trips only) |
Community Transit |
| 512 | Yes | Yes | Lynnwood City Center Station | Ash Way Park & Ride, South Everett Freeway Station | ||
| 513 | No | No | Ash Way Park & Ride | Seaway Transit Center | ||
| 522 | Yes | Yes | Shoreline South/148th Station | 145th Street, Lake City Way, Bothell Way NE, Ballinger Way, Kenmore Park & Ride | University of Washington, Bothell/Cascadia College
Woodinville Park & Ride (select trips only) |
King County Metro |
| 532 | No (use routes 535 & 512) |
No | Downtown Bellevue | Bellevue Transit Center, Totem Lake Freeway Station, Canyon Park Park & Ride, Ash Way Park & Ride, South Everett Freeway Station | Everett Station | Community Transit |
| 535 | Yes | Yes | Bellevue Transit Center, Totem Lake Freeway Station, Brickyard Freeway Station, Bothell Park & Ride, University of Washington, Bothell/Cascadia College, Canyon Park Park & Ride, Alderwood Mall | Lynnwood Transit Center | ||
| 542 | Yes | Yes | U District Station | University of Washington, University of Washington Station, Evergreen Point Freeway Station, Yarrow Point Freeway Station, Overlake Transit Center, SR 520 & NE 51st Freeway Station, Downtown Redmond | Redmond Transit Center | King County Metro |
| 545 | Yes | Yes | Downtown Seattle | Capitol Hill (select trips), Montlake Freeway Station (closed since 2019), Evergreen Point Freeway Station, Yarrow Point Freeway Station, Overlake Transit Center, SR 520 & NE 51st Freeway Station, Downtown Redmond, Redmond Transit Center | Bear Creek Park & Ride | |
| 547 (night route) | Yes (night only) |
Yes (night only) |
Downtown Seattle | Mercer Island Station, South Bellevue Station, Bellevue Transit Center, Spring District Station, Redmond Technology Station, Downtown Redmond Station | Marymoor Village Station | |
| 556 | Yes | Yes | Downtown Bellevue | Bellevue Transit Center, South Bellevue Park & Ride, Eastgate Freeway Station, Issaquah Transit Center | Issaquah Highlands Park & Ride | |
| 560 | Yes | Yes | Bellevue Transit Center | Newport Hills Park & Ride, Kennydale Freeway Station, Renton, Renton Transit Center, Sea-Tac Airport, SeaTac/Airport Station, Burien Transit Center | Westwood Village | Pierce Transit |
| 566 | Yes | No | Redmond Technology Station (select trips)
State Route 520 & NE 40th St (select trips) |
Bellevue Transit Center, Renton, Renton Transit Center, Kent Station (select trips), Auburn Park & Ride (select trips) | Kent Station (select trips)
Auburn Transit Center |
King County Metro |
| 574 | Yes | Yes | Federal Way Downtown Station | Tacoma Dome Station, SR 512 Park & Ride | Lakewood Transit Center | Pierce Transit |
| 577 | Yes | Yes | Downtown Seattle | I-5 | Federal Way Transit Center | |
| 578 | Yes | Yes | Federal Way Transit Center, Auburn Station, Sumner Station | Puyallup Station | ||
| 590 | No (use route 594) |
No (use route 594) |
Downtown Seattle | SODO Busway, Tacoma Dome Station | Tacoma Dome Station
Downtown Tacoma (one early morning trip only) | |
| 592 | No | No | SR 512 Park & Ride, Lakewood Station | DuPont Station | ||
| 594 | Yes | Yes | SODO Busway, Tacoma Dome Station, University of Washington Tacoma, Downtown Tacoma, SR 512 Park & Ride | Lakewood Station
DuPont Station (select trips only) | ||
| 595 | No | No | SODO Busway, Tacoma Community College Transit Center, Narrows Park & Ride, Kimball Drive Park & Ride | Gig Harbor (Purdy Park & Ride) | ||
| 596 | No | No | Sumner Station | SR 410 | Bonney Lake Park & Ride | |
| 597 (night route) | Yes (night only) |
Yes (night only) |
Downtown Seattle | Tukwila International Boulevard Station, SeaTac/Airport Station, Federal Way Downtown Station, Tacoma Dome Station | Lakewood Station |
03Fleet
Sound Transit owns a fleet of 240 buses operated by three different local transit agencies: Community Transit, King County Metro, and Pierce Transit. These buses are maintained at the respective bases for the agencies in Everett, Bellevue, and Lakewood. The fleet includes articulated, double-decker, and high-floor coach buses. Sound Transit buses are painted white with aqua, turquoise, and blue waves along the sides, representing the Puget Sound region ST Express serves, and most feature a freely-adapted representation of the Sound Transit bus and train system map on the seating fabric.
Occasionally, vehicles that are not in Sound Transit livery are used on Sound Transit routes by the operating agencies. Also, Sound Transit vehicles may also be used by the local agencies for other commuter routes.
Sources and credits
This article is adapted from the Wikipedia article “Sound Transit Express”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Sound Transit Express 91717 at Mountlake Terrace TC - wide view.jpg by SounderBruce, CC BY-SA 4.0
- 545 Eastbound at Montlake (5140048599).jpg by Atomic Taco from Seattle, WA, USA, CC BY-SA 2.0
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