LRT vs. BRT to West Seattle: A Mapped Comparison.


December 15, 2015 by seradt

Note: Special thanks to all the guys at the 60CES, Engineering Flight, of Travis Air Force Base. You have been incredible. 


Once again, the debate is taking place on what type of investment should be a priority within a Sound Transit expansion package, this time ST3. Lacking a coherent investment strategy that places due emphasis on the most critical elements of a pre-planned regional transit network (a plan that exists only in the abstract), ST3 is becoming a transportation grab-bag skewed by big ideas, politics, sub-area funding conflict and disorganization. Perhaps the messy process that characterizes these discussions can produce a meaningful plan on which to vote, but the nature of this animal leaves many doubtful.

Certainly, any investment in new rights-of-way and quicker, more efficient transit will become a welcome addition to the Puget Sound mobility system, but it remains essential that the public be critical of each proposal. Seattle and its environs must demand the finest outcomes within a constrained budget, and, indeed, force Sound Transit to respect the supremacy of any budget and maintain their promises to the public. Transportation “technicals” should be provided their due deference as they whittle expensive and complicated plans to their value-engineered best, if not nixing them entirely as white elephants that serve niche markets. With sensible budgets and scope limitation; with a critical body-politic led by a skeptical expertise, and; with logical projects that take advantage of existing infrastructure and urban development patterns, we can promote a finer Puget Sound region that is both more accommodating and affordable to those who choose to reside here. This process will ultimately be dictated by transit access.

A primary focus of the ST3 discussions is upgraded transit service to West Seattle, specifically Alaska Junction, and rightfully so. Here, a historic neighborhood center has been transformed, home to many new residential buildings, restaurants, grocery stores, cafes, and all the other urban amenities for which people clamor. The population density of the area, as evidenced by the 2010 census, is a defined, respectable block of orange in a sea of yellow, indicative of the new energy focused on the area. The energy is made manifest in development patterns that we should endorse through transportation investment that will not only sustain it, but encourage more of it. West Seattle, and Alaska Junction, in particular, are important places, and the city and Sound Transit should acknowledge this truth with a redirection of funds toward sensible, local rapid-transit projects.

Residents of West Seattle have plenty to be cynical about. While they have done their part constructing a secondary urban center within the city that is urbane and lovely, Seattle has responded with lackluster transit provisions that do not effectively tie the area into the urban core. Frustration has mounted with a freighted intensity. RapidRide C-line, popularly championed as bus rapid-transit (BRT), only marginally reduced trip times from the Junction to Downtown, but only on the best of days, and the buses are frequently caught in clogged traffic lanes that must be navigated in the absence of dedicated lanes in critical areas. The buses are frequently bunched at their termini as a result, despite scheduled 7 to 8 minute headways in peak hours, and are often jam-packed with local commuters. Many are driven to the King County Water Taxi and skip the buses entirely. The current solution is not working, and it arguably never has worked.

While the problem in West Seattle is clearly defined, solutions are not.

As Sound Transit and the region continues its unabashed love affair with light rail expansion, of which this blog is a critic, many in West Seattle are longing for inclusion into the system. This desire for incorporation into the Link network is sensible, especially in light of the failings of RapidRide. Rail can be swift, is usually unencumbered by traffic over dedicated right-of-way, and is typically a very smooth ride. These are true statements that speak to the value of quality rail transportation, and, indeed, rail services can be an intelligent investment for the public to make. However, these statements can be true of bus services, too, and, for the RapidRide C-line, the fact that they are not is a major failing of the corridor.

In the debate over upgraded service to West Seattle, it is thus imperative to remember the following:

Just because it rolls over rails does not make a proposal worthwhile, and, alternatively, just because it rolls over tires does not make a proposal inferior.

West Seattle residents are rightful in their indignation toward the current iteration of RapidRide, but rail is not necessarily the panacea that should be sought to address the C-Line’s issues. Nor is the indignation toward bus service deserved. The idea of BRT service for the area is not a misguided one, though its execution here is totally inadequate. For those who long for a traffic-free commute from one of the city’s most important centers and who seek rail infrastructure to provide it, they fail to envision the possibility of a better designed RapidRide providing exactly that. Such a transit luxury could also be provided for billions of dollars cheaper at the most expensive build-out when compared to any new rail extension to West Seattle’s densest neighborhood.

This opinion in favor of BRT over light-rail transit (LRT) to West Seattle is neither an expression of anti-rail bias or even partisanism.

Rail infrastructure best serves areas that look and feel quite like Alaska Junction, or are even more urban, and whose importance as a key neighborhood center is undeniable. These areas are dense and likely growing, featuring healthy development patterns. Rail infrastructure links such centers into a system that builds the foundation for a greater city.  As an isolated case, Alaska Junction is precisely that: important, urban and growing properly. The context of Alaska Junction in the regional picture, however, upends the model that otherwise would support rail investments to the neighborhood.

First, the daily ridership totals on the C-line are not necessarily indicative of a corridor that will be better served, or even should be served, by rail. At approximately 8,300 daily riders (pg. 68), the C-line is not particularly impressive in numbers of people moved. Vancouver’s 99 B-line, for example, a preeminent bus corridor in North America,  hauls nearly 56,000 daily (pg. 65). There is clearly room to grow for the C-line. Though there are other bus routes through West Seattle, none approach the frequencies or prominence of the C-line, and the numbers are therefore telling of the demand for transit in West Seattle: increasing steadily, but not quite noteworthy—yet.

Second, and far more damning, is simply the political and physical geography of West Seattle and its neighborhoods.

Politically, not only are the neighborhood centers disjointed in their arrangement on the isolated peninsula that is West Seattle, the urban centers beyond Alaska Junction are not especially deserving of rail service. More troubling, the areas continue to be entirely surrounded by auto-oriented sprawl. Additionally, any extension of Link to West Seattle would not encounter a meaningful population center until Alaska Junction(!), representing miles of lost revenue and ridership in effort to serve this station. When compared to a hypothetical line serving Belltown or South Lake Union, then Lower Queen Anne, Fremont, and, finally, Ballard, the value of an extension to Alaska Junction is abysmal when we consider its value to the city or region holistically.

Geographically, the peninsula itself exhibits substantial disparities in elevation within short distances, from sea-level to 520′ at High Point (with Alaska Junction resting at roughly 350′). Though LRT can handle significant gradients, beyond 3.5% the machines begin to experience degradation in operational quality, especially on the long ruling grades that would be required to service the hilly terrain of the area. Add the effects of moisture to 4, 5 and 6% grades, or steeper, to multi-car trains and the challenges become self-evident.

Depending upon the particular routing chosen, deep-bore stations may be required. These stations, as they are on Sound Transit’s U-Link extension or New York City’s 2nd Avenue Subway, can often be the most expensive components of any new rail project with subterranean components.

On top of everything else, the rails must vault the Duwamish River, an engineering feat in itself. Compounding this challenge, as if the length of the two waterways (both east and west) were not enough, the span over the Western Waterway either needs a low-level drawbridge to open for shipping traffic, or feature an air draft (i.e., a vertical clearance) of 150′ to avoid this necessity. Pick your poison: keep rail elevation low and suffer service interruptions from tall cargo ships, or erect an extraordinary new LRT bridge with massive approaches.

Third, and the death knell to LRT in this author’s opinion, is cost. Not only is the cost destined to be outstanding—in the multiple billions—due to the challenges related to building rail infrastructure over an industrial river and up and into a hillside, but also due to the overall little benefit of the extension to Seattle and the greater Puget Sound region. The cost/benefit ratio of light rail to Alaska Junction is very poor.

Nonetheless, such an extension is technically feasible.

As with all new transit corridors, there are multiple rights-of-way that can be explored to deliver rail service to Alaska Junction and beyond. However, exhaustive research does suggest that the alignment proposed below, zig-zagging as it does through valleys and vaulting over highways and rivers, is the superior selection.

Alignments farther north of the West Seattle Bridge, including those to Admiral, are superfluous and serve small centers at an extraordinary cost. Otherwise, they become entangled in freeway access ramps and elevated roadways. Alignments farther south of the bridge, especially through Pigeon Point, require taller and longer bridges over a wider, busier section of the Duwamish; require additional and separate segments of tunneling; have direct and unavoidable impacts on the residential community and streets near Delridge Way and the port-industrial clusters along the Duwamish, and; simply do not merit the substantial engineering and planning expenses for a straighter, modestly swifter travel time. Other possibilities, many with popular support, serve the “Avalon Triangle” area adjacent to Fauntleroy Way, but this seems to be a relatively minor net-benefit when compared to alignments that serve the general area with far less community impact.

Mapped below is what a light-rail transit corridor to West Seattle could look like.


  1. Alaska Junction Station
  2. West Seattle Tunnel
  3. Avalon Station
  4. West Seattle Bridge
  5. SODO Station
  6. Holgate Street
  7. Stadium Station

BRT, on the other hand, can handle stiff grades and unexpected route changes; can take full advantage of existing surface infrastructure into Alaska Junction and beyond, and; can take full advantage of the existing multi-lane bridge over the Duwamish River. Additionally, using buses to serve the key stop of Alaska Junction is a far better use of funding and resources than having trains perform the same job. In every conceivable area, not only is BRT better for West Seattle and Alaska Junction over trains, but Alaska Junction is a paramount example of a locale perfectly suited for such services.

Needed to save billions of dollars while rescuing West Seattle from the depravity of clogged freeways, wasted hours, and ruined days is little more than a reallocation of space on existing streets; dedicated BRT-lanes. Unfortunately, this has been complicated for Seattle and the region to accomplish, and it spends billions on new rail infrastructure as a consequence of this ridiculous inability to challenge the primacy of cars (even on key transit corridors).

To ensure precision schedules and guarantee trip times, new access ramps to these dedicated lanes could be constructed onto the West Seattle Bridge and State Route 99, and new transit-only lanes should be reserved on the new Alaskan Way Boulevard, on Avalon Way (and possibly Fauntleroy Way), and finally Alaska Street at a terminal situated immediately east of the traffic light on California Avenue. The forthcoming mapped plan has many of these new BRT lanes in the center of the roadway, but such details can be debated and changed should alternatives prove more intelligent.

The most expensive components of this proposal are the new transit-only ramps to the elevated freeways, which, although their cost is not insignificant, are nowhere as astounding as the cost of a new railroad. If the cost for new ramps prove to somehow be unappetizing to taxpayers, metered access points, or even controlled intersections, could be explored at those areas where buses must cross general purpose lanes to access their transit-dedicated lanes. This would mitigate the need for separated access routes for BRT from general traffic, but metered roads or intersections would push traffic jams into West Seattle streets, and freeway speeds could be hampered by cars accelerating from a stop after the passing of a BRT service. Additionally, if BRT services became very frequent, say every 1-1/2 to 3 minutes, conflicts at such areas may prove too much of a traffic-inducing nuisance. This is why separate lanes and access ramps for BRT are proposed outright.

Mapped below is what an authentic bus rapid-transit corridor to West Seattle could look like.


  1. Alaska Junction
  2. Avalon Way
  3. West Seattle Bridge
  4. Lander Street
  5. Holgate Street
  6. SR99 Tunnel Portals / Stadiums
  7. Downtown Seattle


VERDICT: Seattle and Sound Transit Should Invest In Bus Rapid-Transit to West Seattle.



3 thoughts on “LRT vs. BRT to West Seattle: A Mapped Comparison.

  1. Adam D says:

    The one thing that concerns me about your proposal is the requirement to block of all traffic on Alaska St between California Ave SW and 42nd Ave SW. The problem is that Alaska is the primary method of access to California, still the primary spine for West Seattle, for those getting off the West Seattle Bridge at Fauntleroy rather than Admiral. By closing this block to traffic, particularly westbound traffic, you push some of those people trying to access this portion of California either to the Admiral exit and traversing a longer portion of California, or through the surrounding neighborhood streets, which isn’t ideal and aren’t designed for heavy traffic flow.

    The alternative would be to only block east-bound traffic, i.e., those coming from California trying to get back on to Alaska or Fauntleroy. This would still clear the necessary space to serve as the launching point for BRT from that block, but still allow people coming off the bridge to easily access the busiest part of West Seattle.


  2. Kathy Dunn says:

    Congratulations, you’ve just convinced me that public transportation on and off the peninsula is never going to get any better than it is now. Streetcars served us better a hundred years ago, when we were much less dense, but now they are considered too expensive. Short sighted thinking. We’d better suspend a covered pedestrian/bike/ebike trail under the freeway bridge to get people on and off the peninsula in a safe and timely fashion.


  3. Fraser Pollock says:

    One of the problems of comparing the capabilities of LRT and BRT is that very few people in North America have seen real BRT in operation. The basic model of LRT operation in North America requires transit operators to fully segregate the Light Rail Vehicle or Vehicles in a train in the LRT Right of Way from surrounding traffic. This means that, there is a big inherent passenger carrying capacity already in any existing LRT operation, even if it is not fully used by the system. Any equivalent BRT system must be more than a Bus riding in a painted lane because that is not equivalent to what the standard LRT system is. To match the capacity you have to actually build a BRT right of way that is physically segregated from traffic, you are building a real busway (majority of the entire right of way can’t be painted lanes) that has for safety reasons, at least the capacity for buses to see around buses in front of them which means at the least, 2 running bus lanes that are 3.5 to 4 metres wide or 11.5 -13 feet per lane (which are much wider than LRT rights of way). The stations and stops must hold the equivalent of 2, preferably 3 articulated buses at once and like LRT, if the right of way crosses an intersection, a green light sustaining or red light inhibiting control system must be used.

    Just like a rail system BRT rights of way must have curves and slopes less than a conventional road but can have tighter turns and greater slopes than LRT. If you think trains don’t like significant slopes and tight turns, try most of the conventional modeled articulated buses. If you want to have your busway used properly and efficiently, a real BRT operating plan must be used not a copy of a rail operating plan. Unlike what most people think, BRT and LRT must operate very differently to be effective, it only looks like they operate similarly. Build all of this and then you will have a BRT system that is the equivalent of most major LRT systems. Its not cheap and can be quite complex to operate. Any person who thinks that a BRT system running in painted lanes or mostly open traffic is nowhere near the capacity of a modern LRT system.

    Busway rights of way can use freeway lanes however, you do it at your own risk because freeway lanes have been proven to keep away passengers because it is inherently passenger unfriendly. Some systems put the stations outside of the freeway or on the connecting street leading to the entry and exit ramps of the freeway rights of way to get to the passengers and stations. In any case stations should be no more than a half mile to 3/4 of mile apart at the most to maximize passenger access. Freeway rights of way make this very difficult and can have runs that go for a mile or more between exits and there stations, which is disastrous for ridership.

    Oh yes, the ability for a bus to leave its right of way, giving it greater operational flexibility is based on the idea that the bus is riding in a lane which is not physically segregated which it must be to have the same passenger carrying capacity as a LRT rail line would. Once the bus is physically segregated from other traffic, it is impossible unless there is a place that has been designed as to let buses leave the busway. Painted bus lanes are difficult to keep clear of outside traffic unless there is a great and expensive effort by police and the transit operator to keep all other traffic out! If you want to build a real BRT system that is the real equivalent to a LRT line, a real high capacity busway must be used, if you want to match the capability of rail a real BRT operating plan must be used. It will not be cheap any system of lesser capability and you are not building the equivalent! of a LRT system. You can build a lesser system and it can improve operating conditions but, it will not be true BRT or a real rapid transit system and must be considered a lesser system in the hierarchy of your rapid transit network.


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