RapidRide Future and Prioritization

A bus lane for RapidRide G, opening September 14. Photo by SDOT Photos.

Following major cuts to RapidRide expansions due to budget constraints posed by the pandemic, the King County Council asked Metro in 2021 to, among other things, produce a RapidRide prioritization plan" by the middle of this year. Metro published its plan on June 28, in which it chooses the next RapidRide lines to build as part of the interim network" intended to be operational before the Ballard Link Extension is finished in 2039.

The 61-page document, summarized in a Metro staff report, assesses eight corridors identified in the 2021 Metro Connects Interim Plan using a prioritization framework weighted heavily for equity and environmental sustainability, but also considers travel time, ridership, cost, and feasibility. These new routes would continue expanding RapidRide into a grid-like network building on the seven lines operating today (A, B, C, D, E, F, and H) and the five lines already in on the way (G, I, J, K, andR).

Typical for RapidRide lines, the plan proposes transit speed improvements ranging from BAT (business access and transit) lanes to queue jumps to address existing travel time delays. However, the high cost of additional infrastructure upgrades and lack of funding limits Metro's ability to implement more than three or four routes by 2039.

Prioritization Outcome

Metro's Staff Report summarizes the status of the current RapidRide system expansion projects: RapidRideG will start running in September of this year; RapidRideI is slated to start construction in 2025 and finish by 2026; RapidRideJ is under intent to start construction this year and finish by 2027. For the two lines paused in 2020 pending funding, RapidRideK is now expected to open in 2030 and RapidRideR in 2031. RapidRideK formally restarted planning earlier this year; RapidRide R will resume the planning process next year.

Looking beyond the lines currently in planning, Metro has assessed eight candidate corridors to determine where and when the next RapidRide lines should go.

Figure 1 from Metro's RapidRide Prioritization Plan, mapping the candidate corridors.

Above is the map of prioritized routes with the descriptions below.

Corridor Id	Route Name	Description
1993	40	Northgate, Ballard, Downtown Seattle, First Hill
1012	44	Ballard, Fremont, UW (Montlake Triangle)
1064A	36+49	(Not chosen) Othello, Beacon Hill, Broadway, University District
1064B	36	Othello, Beacon Hill, Jackson Street, Downtown Seattle
1052	150	Kent, Southcenter, Downtown Seattle
3101+1028	B Line + 271	University District, Bellevue, Crossroads
1999	B Line + 226	Redmond, Overlake, Crossroads, Eastgate
1052	165	Highline College, Kent, Green River College
1056	181	Twin Lakes, Federal Way, Auburn, Green River College

The King County Council instructed Metro to assess each of these corridors with a strong priority on equity and sustainability, and Metro tested a few different formulas to competitively rank each corridor.

Table 65 from Metro's RapidRide Prioritization Report, showing results of different weighting approaches regarding equity and sustainability.

Based on these results, Metro developed three tiers of prioritization and categorized each candidate corridor: Tier1 corridors are the highest priority for upcoming expansion; Tier2 corridors would be next in line if additional funding or capacity becomes available; Tier3 corridors would not be developed until after 2040 but are still candidates for Metro's 2050 network.

Visual summary of corridor priority tiers, from Metro's RapidRide Prioritization Report.

After the currently planned RapidRide lines are built, the Tier 1 Route150 and Route36 would be the next RapidRide routes. Tier 2 Route44, Route40, and BLine/Route271 might be built before 2040 if funding is available. Tier 3 Route181, Route165, and BLine/Route226 are essentially pushed to 2040-2050.

RapidRide SpreadingExisting, planned, and prioritized RapidRide corridors (red), with all-day ST Express bus routes (blue) and Link (black), from Metro Connects' Interim Network map.

The new RapidRide lines combined with the existing and planned ones will create new north-south and east-west all-day connectivity throughout King County. If King County actually implements all these candidate projects, it will form a grid of north-south and east-west RapidRide lines in South King County, create through-running bus routes on the Eastside, and complete Seattle's hourglass.

The restructures will typically involve realigning diagonal routes or L-shaped routes into north-south and east-west bus routes, creating one higher frequency route and truncating the remainder segment. However, the increased frequency on existing and new routes comes at the expense of increased transfers to major destinations. For example, the Route 372 truncation to Shoreline South Station or the Issaquah's Route 554 to South Bellevue station, both of which would force through-riders to transfer to a different line.

To follow along, here are some helpful webmap links:

RapidRide Prioritization Remix (Posted 2024)
Metro Connects Interim Network Remix (Posted 2021)

South King County GridMetro Connects Interim Network

South King County would have three east-west RapidRide lines with RapidRide F, Route 165 and Route 181. As well as three north-south RapidRide lines with RapidRide A, Route 150 and RapidRide I. This creates new prominent transit transfer nodes along SR 516 at Highline College with the existing RapidRide A, Route 165, and Kent Des Monies Link Station as well as at Kent Downtown with RapidRide I, Route 150, Route 165 and Kent Sounder Station.

To build the grid, the existing Route 165 from Green River College via Kent to Burien would be truncated at Highline College. While Route 180 (future RapidRide I) was already reorganized heading after Kent to Renton instead SeaTac. One major change in the RapidRide Prioritization Plan from Metro Connects is the rerouting of Route 165 to SR 516 instead of S 240th Street in Kent. Using the new transit grid would involve more transfers on a trip from Auburn to SeaTac or from Kent to Burien, but in exchange for increased frequency.

Eastside Through-RunningMetro Connects Interim Network

Eastside transit routes are currently centered around Bellevue with radial routes in 6 directions; this pattern will continue in the future. However, these are all currently separate routes such as 250, 226, 550, or RapidRide B that terminate in Bellevue, besides the Route 271 which through-runs. In the future, there will be three through-running transit routes with Seattle to Redmond (via East Link), Kirkland to Eastgate (via RapidRide K), and UW to Crossroads (via RapidRide B + 271) allowing easier connections.

Simplified Eastside Map highlighting transit currently terminating in Bellevue (left) versus proposals for through-running service (right).

With the expansion of Link, many bus lines are proposed to be truncated at a closer Link station in exchange for higher frequency. For Northgate Link, Route 255 was already truncated at UW rather than downtown Seattle for supposed increased frequency but unfortunately the frequency actually decreased due to budget constraints. The East Link Connections" restructure will truncate the existing Route 271 and Route 554 (I-90 to Seattle) lines to Issaquah into the new Route 554 from Bellevue to Issaquah heading up Bellevue Way. Meanwhile, the Route 544 from Downtown Seattle to Redmond will be deleted and only the Route 542 from UW to Redmond will remain.

The new proposed RapidRide K would merge Route 250 and the current southeast portion of Route 271 to form a radial line from Totem Lake via Kirkland then Bellevue to Eastgate. The remainder leftover portion of Route 250 would be from Avondale via Redmond to Kirkland.

The existing RapidRide B route, currently forming an L" shape, is proposed to split into a east-west and north-south portion with the former merged with Route 271 to create a line from University District to Bellevue to Crossroads. The new north-south RapidRide B + 226, the only RapidRide not heading through downtown Bellevue, would continue to travel from Redmond to Crossroads but then continue further south to Eastgate taking over the former Route 226s path. The reorganization and through-running will allow faster transit trips removing one transfer for some trips such as from Crossroads to UW and from Eastgate to Kirkland or to Redmond.

For major changes in the RapidRide Prioritization Plan from Metro Connects, the Eastside RapidRide B + 271 will continue to use Bellevue Way NE similar to new Route 270 rather than exiting earlier on SR 520 for 84th Ave NE though Medina. RapidRide B + 226 removes the detour to Overlake Transit Center for a faster bus route though missing the connection.

Seattle RapidRide HourglassMetro Connects Interim Network with Seattle RapidRide lines

Currently most of Seattle's major bus routes run through downtown Seattle with some buses terminating in the U-District now that Link serves the U-District and Northgate. The upcoming RapidRide G, Lynnwood Link, and Stride S3 further reorganizes existing routes into east-west and north-south lines usually reaching Link stations.

After RapidRide J and RapidRide G, there would be three more lines for Seattle with upgrades to Route 36, Route 40, and Route 44.

Route 44 as a RapidRide is generally the same as before, however would continue to heading to Montlake Triangle rather than heading to U Village as in the earlier Metro Connects concept. Route 40 as a RapidRide will detour over to 15th Ave NW for Ballard Link Station, and its southern terminus will extend to First Hill. Route 36 as a RapidRide has two potential alignments: Alignment A would merge with Route 49 to create a new north-south route from U District via Capitol Hill and Beacon Hill to Othello Station; Alignment B would remain like the 36 is now, going to downtown Seattle. Alignment A was not carried forward as a candidate corridor in this plan and Alignment B was selected for prioritization.

With these RapidRides, Seattle would have 11 lines completing the hourglass formation, with C, H in West Seattle; R, 36, 150 in South Seattle; G in Central District; J, 44 for UW; and finally D, E, and 40 in North Seattle.

Up Next

Over the next several days, subsequent articles will dive deep into each of the eight prioritized RapidRide corridors, looking into the additional alignments considered, the BAT lanes suggested, and RapidRide station locations. We will highlight relevant extra information from the appendixes such as current time delays, intersection analysis, current ridership data, estimated future ridership data, and estimated cost breakdown. Lastly, we will guess how likely the RapidRide lines are to be implemented based on given construction costs and/or political considerations.