Sound Transit Express
Sound Transit 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 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, the system had a ridership of, or about per weekday as of.
Unlike a typical transit bus, 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.
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.
Fares
ST Express uses a flat fare system, where each ride costs the same regardless of distance.The fares are as follows:
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 fare to match Link Light Rail fare in March 2025
Routes
23 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 2024 are:
| Route | Off-peak service | Weekend service | Start | Via | End | Operator |
| 510 | Downtown Seattle | I-5, South Everett Freeway Station, Mountlake Terrace Freeway Station | Everett Station ---- Downtown Everett | Community Transit | ||
| 512 | Lynnwood City Center Station | Ash Way Park & Ride, South Everett Freeway Station | Everett Station ---- Downtown Everett | Community Transit | ||
| 513 | Lynnwood City Center Station | Ash Way Park & Ride, Eastmont Park & Ride | Seaway Transit Center | Community Transit | ||
| 515 | Lynnwood City Center Station | I-5, Mountlake Terrace Freeway Station | Downtown Seattle | Community Transit | ||
| 522 | Roosevelt Station | Lake City Way, Bothell Way NE, Ballinger Way, Kenmore Park & Ride | University of Washington, Bothell/Cascadia College ---- Woodinville Park & Ride | King County Metro | ||
| 532 | Downtown Bellevue | Bellevue Transit Center, Totem Lake Freeway Station, Brickyard Freeway Station, I-405 & NE 195th, Canyon Park Park & Ride, Ash Way Park & Ride, South Everett Freeway Station | Everett Station | Community Transit | ||
| 535 | Downtown Bellevue | 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 | Community Transit | ||
| 542 | 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 | Downtown Seattle | Capitol Hill, Montlake Freeway Station, 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 | King County Metro | ||
| 550 | Downtown Seattle | Mercer Island Park & Ride, South Bellevue Park & Ride, Bellevue, Bellevue Transit Center | Bellevue | King County Metro | ||
| 554 | Downtown Seattle | Mercer Island Park & Ride, Eastgate Freeway Station, Issaquah Transit Center, Issaquah Highlands Park & Ride | Issaquah Highlands Park & Ride ---- Redmond | King County Metro | ||
| 556 | U District Station | University District, University of Washington, University of Washington Station, Evergreen Point Freeway Station, Yarrow Point Freeway Station, Bellevue Transit Center, South Bellevue Park & Ride, Eastgate Freeway Station, Issaquah Transit Center | Issaquah Highlands Park & Ride | King County Metro | ||
| 560 | 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 | Remond Technology Station ---- State Route 520 & NE 40th St | Bellevue Transit Center, Newport Hills Park & Ride, Kennydale Freeway Station, Renton, Renton Transit Center, Kent Station, Auburn Park & Ride | Kent Station Auburn Transit Center | King County Metro | ||
| 574 | Sea-Tac Airport | SeaTac/Airport Station, Kent/Des Moines Freeway Station, Star Lake Freeway Station, Federal Way Transit Center, Tacoma Dome Station, SR 512 Park & Ride | Lakewood Transit Center | Pierce Transit | ||
| 577 | Downtown Seattle | I-5 | Federal Way Transit Center | Pierce Transit | ||
| 578 | Downtown Seattle | Federal Way Transit Center, Auburn Station, Sumner Station | Puyallup Station | Pierce Transit | ||
| 580 | Puyallup Station | 9th St SW | South Hill Park and Ride | Pierce Transit | ||
| 586 | University District | University of Washington Medical Center, SR 520, I-5, Federal Way Transit Center | Tacoma Dome Station | Pierce Transit | ||
| 590 | Downtown Seattle | SODO Busway, Tacoma Dome Station | Tacoma Dome Station ---- Downtown Tacoma | Pierce Transit | ||
| 592 | Downtown Seattle | SR 512 Park & Ride, Lakewood Station | DuPont Station | Pierce Transit | ||
| 594 | Downtown Seattle | SODO Busway, Tacoma Dome Station, University of Washington Tacoma, Downtown Tacoma, SR 512 Park & Ride | Lakewood Station ---- DuPont Station | Pierce Transit | ||
| 595 | Downtown Seattle | SODO Busway, Tacoma Community College Transit Center, Narrows Park & Ride, Kimball Drive Park & Ride | Gig Harbor | Pierce Transit | ||
| 596 | Sumner Station | SR 410 | Bonney Lake Park & Ride | - |
Fleet
Sound Transit owns a fleet of 360 buses operated by three different local transit agencies. 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. This is due to vehicles having mechanical problems, vehicle allocation issues, and assignment errors.
| Manufacturer and model | Image | Length | Passengers | Purchased | Qty | Fleet numbers | Operator |
| New Flyer DE60LF | 150px | 60' | 56 | 2008 | 2 | 9622–9623 | King County Metro |
| New Flyer DE60LF | 150px | 60' | 56 | 2010 | 13 | 9624–9636 | King County Metro |
| Motor Coach Industries D4500CL | 150px | 45' | 57 | 2008 | 7 | 9713–9719 | Pierce Transit |
| Motor Coach Industries D4500CL | 150px | 45' | 57 | 2009 | 3 | 9720–9722 | Pierce Transit |
| Motor Coach Industries D4500CL | 150px | 45' | 57 | 2010 | 17 | 9723–9739 | Pierce Transit |
| New Flyer D60LFR | 60' | 56 | 2010 | 13 | 9553–9565 | Community Transit | |
| New Flyer D60LFR | 60' | 56 | 2011 | 1 | 9566 | Community Transit | |
| New Flyer D60LFR | 60' | 56 | 2011 | 17 | 9567–9583 | King County Metro | |
| New Flyer D60LFR | 60' | 56 | 2011 | 3 | 9584–9586 | King County Metro | |
| New Flyer D60LFR | 60' | 56 | 2011 | 10 | 9587–9596 | King County Metro | |
| New Flyer D60LFR | 60' | 56 | 2012 | 14 | 9800–9813 | King County Metro | |
| New Flyer D60LFR | 60' | 56 | 2012 | 5 | 9818–9822 | King County Metro | |
| New Flyer DE60LFR | 150px | 60' | 56 | 2010 | 11 | 9637–9647 | King County Metro |
| New Flyer DE60LFR | 150px | 60' | 56 | 2011 | 4 | 9648–9651 | King County Metro |
| Gillig Low Floor BRT Hybrid | 40' | 35 | 2012 | 22 | 9201–9222 | Pierce Transit | |
| Gillig Low Floor BRT | 40' | 35 | 2012 | 2 | 9122–9123 | Pierce Transit | |
| Gillig Low Floor BRT | 40' | 35 | 2015 | 3 | 9124–9126 | Pierce Transit | |
| New Flyer Xcelsior XDE60 | 60' | 57 | 2014 | 8 | 9652–9659 | King County Metro | |
| New Flyer Xcelsior XDE60 | 60' | 57 | 2014 | 7 | 61401–61407 | Pierce Transit | |
| New Flyer Xcelsior XDE60 | 60' | 52 | 2020 | 31 | 9660–9690 | King County Metro | |
| New Flyer Xcelsior XD60 | 60' | 57 | 2014 | 4 | 9814–9817 | King County Metro | |
| New Flyer Xcelsior XD60 | 60' | 57 | 2014 | 3 | 51401–51403 | Pierce Transit | |
| Alexander Dennis Enviro500 MMC | 42' | 82 | 2015 | 5 | 91501–91505 | Community Transit | |
| Alexander Dennis Enviro500 MMC | 42' | 82 | 2017 | 32 | 91701–91732 | Community Transit | |
| Alexander Dennis Enviro500 MMC | 42' | 82 | 2020 | 13 | 91901–91913 | Community Transit | |
| Gillig Low Floor BRTPlus CNG | 40' | 35 | 2015 | 17 | 41501–41517 | Pierce Transit | |
| Gillig Low Floor BRTPlus CNG | 40' | 35 | 2016 | 5 | 41601–41605 | Pierce Transit | |
| Motor Coach Industries D4500CT CNG | 45' | 57 | 2016 | 12 | 9301–9312 | Pierce Transit |
