Solving the Ballard Conundrum

Today ST released a presentation on potential alignments for the Interbay/Ballard segment (as well as others) of light rail that’s part of ST3. None of the alignments in the presentation come as a surprise, save for possibly a proposed fixed bride from the edge of Magnolia to around 17th ave in Ballard. But all of them fail to effectively mitigate the fundamental trade off with the Ballard alternatives, namely strong service to the Ballard core (and to a lesser extent decreased noise impacts) verse the substantial costs imposed by tunneling under the ship canal. Below is a proposed alternative that attempts to solve both of these problems reasonably effectively.

Ballard conundrum

Going north from Interbay, the alignment (Green Line) would cross the ship canal with a relatively high movable bridge (70 feet above canal level) landing on the north side of the ship canal at 14th ave. 14th ave would have two stations, one just north of Leary and one just north of Market. Both stations would be elevated with the Leary Station likely substantially so due to the constraints of having a tall bridge over the ship canal. This is similar to the “East of BNSF/14th/Movable Bridge alternative proposed in the presentation. That option was the only option that had a cost profile in line with the representative alignment that went to voters. All other alignments were substantially more expensive.

However, this alignment would not serve central Ballard.* To do that, the proposal adds the Yellow Line running elevated between the Leary Green Line station and Market and 20th. This stub line would be about .75 miles long and require a transfer at the Leary station to get to the rest of the system. The Yellow line would operate with timed transfers to Green Line downtown service, reducing the transfer penalty to a reliable 1 or 2 minutes instead of an unreliable 0 to 6 – 10 minutes (or worse at night). Since the line doesn’t connect to the main system, the Yellow line would only need stations supporting one or two car trains, substantially reducing capital costs.

Having a stub line to serve downtown Ballard, is not a perfect substitute for direct service, but it has several advantages over alternatives.

This proposal serves more destinations

Instead of having one Ballard station this proposal has three stations, substantially increasing the light rail walkshed.

This proposal is (very likely) cheaper than subway alternatives

According to the Seattle Times, the marginal cost of tunneling to Ballard is $450 million, which it also estimates to be similar to about 2 miles of additional elevated. That $450 million figure seems low to me, but I can’t find a better number. Given that the Yellow Line plus a slightly longer Green Line add a little less than a mile of elevated or at grade track, it’s far more plausible that this alternative can fit within budget constraints.

It effectively sets up future extensions to Northgate and/or the U-district

The Green Line would be extremely well situated to continue north to Northgate and the Yellow Line would be extremely well situated to continue east to the U-district. These potential extensions are colored pink and purple respectively in the diagram above. Building these as separate lines fits a reasonable long term vision for the network.

It supports heavier upzoning in a less developed area

It’s worth remembering that this project is expected to be complete 15 to 20 years from now. East Ballard has substantial potential to grow during that time and as an industrial area near desirable walkable areas, it represents an excellent opportunity for transit oriented development much like South Lake Union did 20 years ago. Getting East Ballard up to the level of density of at least West Ballard constitutes a laudible goal. Alignment decisions should support efforts to give more people the opportunity to live in Seattle.

It provides an excuse to fix the annoying 5 way Leary/20th/Market intersection

With the Ballard station on Leary, at least part of the street would be taken by the station. Ideally, that block of Leary would be closed to cars (or function as a deadend) with cars utilizing alternatives such as 15th to Market, 20th to Market or Shilshole ave. Five way intersections are generally a anti-pattern both from the perspective of walkability and from a traffic flow perspective. Alternatively Leary Way could function as a one way street southeast bound  at that intersection, allowing some traffic flow without requiring an extra light cycle.

Ballard Station would be close to street level.

The Ballard station could plausibly be built at grade. In contrast, a tunneled station could potentially be very deep. The quicker station access times in this proposal negate some of the travel time costs imposed by having an additional station and transfer.

A 70 foot movable bridge offers majestic views

This last one should speak for itself.


Ideally the Yellow Line would be automated minimizing the money spent on dwelling operators, but operational costs shouldn’t be overwhelmingly higher. Non-revenue track would also need to built between the Green Line and Yellow Line so that Yellow Line trains can access an operations and maintenance facility, adding some additional cost to the project.

Overall decoupling getting across the ship canal from serving downtown Ballard provides the opportunity to affordably build strong service coverage of Ballard and should be seriously considered by ST and relevant stakeholders.


*a movable bridge also raises reliability concerns, but I think these are overblown delaying potentially one to two trains a day for about 4 minutes. That’s not ideal, but in the context of around ~300 runs a day, it averages to a negligible increase in delays. And the system wide impacts of such delays can largely be mitigated by running the delayed train express for a few stops to make up time.


Romanticism, Rail bias and why riding Link Light Rail can be so damn irritating.

Last summer I read the book Zen and the Art of Motorcycle Maintenance a philosophical text that deeply examines what constitutes “quality” (among other things). In the book, the author describes two ways of looking at the world, the classical and the romantic. The classical perspective focuses on the components and design behind something (one might say it’s an analytical perspective). In contrast, the romantic perspective focus on the thing itself as a whole and focuses on being in the moment. While the author initially focuses on the benefits of classical thinking, particular for its ability to help one fix and maintain a motorcycle, the author ultimately believes that both of these perspectives are essential and that a critical task for humans is to transcend being tied down to either perspective on reality.

When discussing transit on this blog, my perspective has been overwhelming, if not entirely, classical. I assessed the quality of ST3 plans by digging into project components like costs, travel times and projected ridership, the component parts that seemingly (maybe should) make a transit investment valuable. But the reality is that the romantic perspective towards transit plays a large role in how most people perceive the quality of transit and indeed in the experience of transit itself. Most people take transit and support (or don’t do those things) for decidedly less technical reasons. It therefore deserves some discussion.

“Rail bias,” the idea and to a lesser extent empirical reality that many people strongly prefer trains when given the choice between trains or buses with otherwise similar service quality (e.g. reliability, travel times etc.), represents an example of romanticism in action. Many people prefer trains not for function but for form. Trains are charming, cool, slick and the evoke in many a feeling of quality that simply cannot be replicated by a bus. In this context, attempting to convince people to ride or support cheaper bus proposals with similar functional attributes to a rail alternative requires changing a core component of people’s worldview, namely apply a classical perspective and ignore the romantic one. While changing this component of people’s worldview may be a worthwhile endeavor, it doesn’t help us make better decisions about transit in the short-term.

What may help though is noting the malleability of these perspectives. Not everyone views rail the same way. While I fell in love with transit riding the train systems of DC and Atlanta (where my cousins and grandparents lived respectively), I don’t feel the same affection towards Link. In particular, I sometimes find the experience of riding Link Light Rail extremely irritating. Not because of anything related to trip time, reliability, frequency or other hard metrics, but because I know that Link was planned and designed relatively thoughtlessly. This lack of quality in design harms the in the moment experience of riding the train for me. Thus, my romantic perspective reduces my overall perception of Link as a mode of travel. An even better example of this is Seattle’s streetcars which were planned with such thoughtlessness that I loathe riding them, function be damned.

Romantic perceptions matter and they should matter as they help form the real world experience of transit. This claim has at least two implications. First, transit advocates and this blog in particular should avoid always analyzing transit from the classical perspective. It’s sensible to focus on these classical aspects, especially because that’s more or less the stated purpose of this blog, but it’s important to contextualize and synthesize this classical analysis with a more holistic understanding of quality.

Second, greater effort should be made to expand or modify the scope of romantic quality in transit. This requires acknowledging that romantic notions of beauty are malleable, as my feelings towards light rail demonstrate. People have the ability to modify their views on trains and buses and people can expand their view on what constitutes quality if given a compelling vision that appeals to their romantic perspectives. It’s wrong to deny or downplay the existence of rail bias, but viewing it as a static unchanging reality and designing to that standard is equally misguided.

Revising Sound Transit 3

The following paragraphs are the comment I will be sending on the proposed Sound Transit 3 package. The comment period closes Monday May 2nd, 2016 at 5:00pm PST

Dear Sound Transit:

At a high level, I don’t really see the value (compared to the cost) of much of the investments being made in ST3. The vast majority of rail proposed is either mostly redundant with existing Link (the second downtown tunnel, the second SODO segment, and the Factoria to Wilburton segment), or follows freeways (West Seattle, the spine segments, Issaquah and Redmond light rail) out to far-flung areas distant from much actual or potential dense, walkable, ridership generating areas.

With regards to the freeway rail, these are corridors where simply increasing restrictions on HOV lanes to ensure reliable fast grade separated free flow for buses would have huge impacts at little to trivial cost, especially given that Sound Transit has already built (or will soon be building) much of the capital needed to make that system work very effectively. When WSDOT reports that 48% of the people traveling on I-5 southbound during peak period at Northgate travel in the HOV lanes (and 35% on transit), it is simply nonsensical that we are planning to spend billions of dollars of capital over two-plus decades to get the speed and reliability benefits that transit riders deserve on I-5 today given their relative usage of the roadway. I understand that it’s not in Sound Transit’s scope to reallocate road resources, but this is the context in which we can evaluate the benefits and costs of these proposals.

Simply put, extending the spine further south, north and east from its currently funded termini is not worth the cost. The subsidy per rider (after operations and fares) is roughly on the order of $10 per rider after fares ($6 to Federal Way, $8 dollars to the Tacoma Dome, $13 dollars to Everett and $16 for Redmond), which is hard to justify in any context, let alone one in clearly superior non-complex counterfactuals exist and one in which opportunities for effective transit orientated development appears minimal. A similar claim can be made about Issaquah rail and arguably West Seattle rail as well.

But it’s not reasonable to let a perfect plan be the enemy of a good one so the onus is on Sound Transit to make the suburban lines and urban lines as strong as possible to negate the inherent wastefulness of freeway-oriented rail spending in the deep suburbs.* As the plan stands, I won’t vote for this. However, I think the plan is salvageable with some plausible changes.


The middle-level issue with what is proposed is that the insistence on building rail to particular places and completing the spine forces other alignments to be suboptimal. The negative externalities of alignment decisions ought to more carefully considered and if Sound Transit cleaned up one of the following two glaring issues in their final proposal (along with insisting on an I-5 alignment with a Paine Field spur, stub or BRT in Snohomish County) I would probably get on board with the proposal.

The first alignment with huge negative externalities is the completion of the spine south of the funded Highline CC station. Currently, the East King rail projects grade as generally awful with subsidies per rider between $15 to $20 per rider after fares, a preposterously high number. A seemingly more efficient use of East King resources would be rail in Renton as part of an east-west line between Burien, TIBS, Southcenter and Renton. Preliminary studies of that alignment had an order of magnitude lower cost per rider projections (something closer to $7 to $10) and it would also serve some of the region’s poorer residents as well as areas seemingly more ripe for large-scale development and growth. Renton, in particular, is fairly centrally located, mostly has an existing street grid, and room to grow and working to spur TOD in that area would go a long way towards improving the economic fortunes of the more southern, poorer parts of King County.  Simply put, the best place to invest East King County resources is in Renton.

But of course, South King County lacks the resources to both build the spine towards Federal Way and build their half of a Burien/Renton line. So the insistence on building the spine in South King County comes at the expense of a far more efficient use of resources in East King County and thus a better package overall.

It’s worth adding here that Pierce County would also be better off with additional urban service over completing the spine. The Tacoma link extension to Tacoma CC grades out as the best investment outside of Seattle in terms of cost effectiveness** and Tacoma is a relatively dense urban area that would attract a lot more local jobs and resources by enhancing connections within the city instead of attempting to be a bedroom community for Seattle. Moreover, it is unambiguous that urban service generally helps poorer people relative to commuter service. Urban service is also more conducive to TOD, the promotion of walkability and ultimately the attraction of the types of young talented individuals and companies that make Seattle and certain other American cities so robust economically.

Overall the insistence on completing the spine probably reduces the package’s utility for the South King, East King and Pierce County subareas combined by 30% to 50% verse the counter-factual of the rail options discussed above plus spending on whatever existing projects had enough funding. For example, if the Renton/Burien line had a $9 dollar per rider subsidy and capital costs similar to the Federal Way and Issaquah rail extensions combined, the Renton/Burien line would be about 45% better than the Federal Way and Issaquah lines combined. And the benefit for Pierce County would be the relative value of an additional urban line over the completion of the spine. Even if that latter figure is negligible, the 45% improvement is huge and represents a billion dollars of value or more.


The second externality issue comes with the West Seattle rail alignment in Seattle. Beyond redundant rail in SODO, building a West Seattle line requires building an expensive second downtown tunnel because only two of the three lines going south from the International district can use the existing tunnel. But in terms of inherency, the Ballard line doesn’t have to go all the way to the ID and could instead continue east from Madison (or Westlake) towards the dense job center of First Hill, the densifying neighborhood of the CD (in particular around Jackson and 23rd) and Judkins Park station for transfers to East Link.

Consider the counterfactual of building that extension of the Ballard line instead of the West Seattle line. If you assume net costs of $900 million (1 net mile tunnel plus 0.6 net miles elevated) over the proposed Ballard to Downtown line and an additional 24,000 riders for that additional segment, the cost effectiveness of the Seattle investments would increase by about 11%. Moreover, such a change would free up funding for bus improvements for West Seattle (including direct off-ramps to the SODO busway, which are desperately needed yesterday), for building the Interbay segment elevated, and for automating the line because it is not interlined with Link, with the resulting frequency and operational improvements. These additional benefits could easily improve the utility of the Seattle investments by 20% or more.

As with the Burien/Renton counterfactual, this is an improvement worth potentially billions of dollars. Indeed, given that First Hill is one of the biggest and densest employment centers in the state and contains a key regional asset in Harborview Medical Center, it is somewhat perplexing that HCT is not even being considered there. Regardless, at minimum, Sound Transit should design Madison station so an extension east to First Hill and the CD can be easily built in the future.***


As it stands the costs of these projects are in many cases not worth the benefits. Sound Transit should push to get its subsidy per rider values closer towards at maximum $7 dollars per rider, and ideally better. Roughly speaking, that cost/benefit is in the ballpark of being worthwhile. In a similar vein, Sound Transit should stop focusing on describing the reality of congestion in the region  and instead focus on how Sound Transit’s specific ideas will actually improve the mobility and well-being of people in this region. Because while we all know that the Puget Sound region has substantial mobility problems, this particular package doesn’t constitute a solution to this problem and instead represents a waste of tax payers dollars.


Alex Bailey


*Beyond the counterfactual of free-flowing transit on freeways, rail to the deep suburbs generally does not support high ridership. While transit is great for urban to urban trips and good for suburban to urban trips, it’s not very helpful for suburban to suburban trips because cars are almost always superior for such trips and suburban car ownership rates are very high. This means that all the potential trips from stations in the deep suburbs are long trips of at least 30 minutes because that’s how long it will take to reach the urban areas from the deep suburbs riding Link. Outside of commuting, people rarely make trips this long and so it’s hard to generate all that much ridership (and in turn value) from HCT in the deep suburbs.

**To be clear, cost per rider is not the only metric on which projects should be evaluated. Hours saved, development opportunities, long-term ridership growth, and social equity also matter. But there is little evidence that most of the freeway segments will spur particularly large amounts of development or score particularly highly in these other areas compared to potential counterfactuals. Overall when one proposal has substantially better cost effectiveness than another proposal then we should consider it substantially better unless there are extremely compelling reasons not to.

***On the topic of the Ballard line, I also support the west is best alignment in Interbay, as rail on 15th will have serious construction disruptions and reliability issues.

The Seattle Alignments and the Hidden Costs of West Seattle Rail

The Sound Transit 3 proposal package can roughly be divided into two parts, the suburban projects and the urban projects (the suburban projects could in turn be further divided into completing the “spine” and the eastside). The urban projects are the projects located in Seattle that are intended to serve Seattle residents. Of course, these projects will also serve suburban residents (at least much more so than suburban projects) because many Seattle neighborhoods are high-density employment centers that are not readily accessible by car, at least during rush hour.

My previous posts have mostly concerned some of the issues around the suburban projects, namely their poor cost-effectiveness and issues around freeway based alignments. This post intends to look at the issues around the urban projects, as well as propose a (in my view) superior alternative.

Let’s start by getting the facts straight. By the basic numbers, Ballard has by far the best ridership per dollar. Using the most recent numbers from Sound Transit, and basic assumptions of upfront payment of costs, 30 years of operation and a 20 year wait before service opens, Ballard has an extremely low cost per rider and is over 2.3 times more cost-effective by this metric as compared to West Seattle link as seen in Table 1 below.

Table 1:

Ballard WS Table 1

However, these numbers are misleading. The 129,500 figure for Ballard ridership includes ridership on South Link that will use the new tunnel, but only to go to/from the downtown stations to points further south. This is effectively ridership that would use the old tunnel under a no-build scenario. In order to compare West Seattle rail and Ballard rail apples to apples we need to use ST’s estimate of 67,000 riders that actually board or alight from the stations north of Westlake.

We also need to update the costs for both Ballard and West Seattle. Sound Transit maintains that the existing tunnel cannot have three separate lines (South Link, East Link and West Seattle Link) all sharing the same tunnel, as it would water down each branch’s headway to an unacceptably low 9 minutes. For similar reasons, Ballard Link also can’t use the existing tunnel. So in effective terms both lines require building the second tunnel and so the cost of said tunnel should be split evenly between the two lines for accounting purposes. Table 2 below shows these numbers under the assumption that the downtown tunnel is 1.25 miles at $750 million per subway mile.

Table 2:

Ballard WS Table 22

As you can see, the Ballard segment still grades out as more useful than the West Seattle segment. But the difference is closer to 33% better not 130% better. Combining these two columns we can derive the cost effectiveness of the Seattle rail projects as shown in Table 3.

Table 3:

Ballard WS Table 32

This $5.27 figure is ok, but these numbers can be improved upon with better routing decisions. I noted earlier that the West Seattle and Ballard lines required construction of a second Downtown tunnel. But this isn’t exactly true. Building a West Seattle line requires a downtown tunnel because only two of the three lines going south from the International district can use the existing tunnel. But the Ballard line doesn’t have to go all the way through Downtown. It can instead head east towards First Hill and the Central District. Because Sound Transit obstinately refused to ever study real transit to First Hill in this round, we don’t have exact counterfactuals, but let’s consider the Green Line in the image below, serving Madison, First Hill near Broadway and Jefferson, the Central District near 23rd and Jackson and Judkins Park station.

Green Line


For ridership, if we assume that Interbay gets about 7,000 boardings then on average an urban station for Ballard link is worth 12,000 boardings. So First Hill station would account for an additional 12,000 riders. The Central District and Judkins park are somewhat less dense so let’s estimate that combined they add an additional 12,000 riders bringing the total to 24,000 riders.

For costs, the net cost of a First Hill alignment over building a downtown tunnel would be about 1 mile of additional tunneling plus 0.6 miles of additional elevated track. At costs of $750 million per mile tunneling and $250 million per mile elevated (in line with the West Seattle rail alignment), the total net cost would be about $900 million, or about $1 billion dollars less than West Seattle rail. That leaves $1 billion dollars in Seattle’s budget, enough money to build direct access ramps between the West Seattle bridge and the SODO busway ($200 million) and completely grade separate the Interbay section ($400 million), with potential additional funds for infill stations, improved amenities around stations, a ship canal tunnel or other short-term improvements.

The alignment change also has an additional cost/benefit advantage. With the Ballard line not interlining with an existing Link line, the Ballard line can be automated (it could also have smaller station footprints and hence cheaper capital costs but I am ignoring that complexity for now). Automation comes with substantial operational efficiencies, as well as making it cheaper to maintain high frequency at off hours. Based on Vancouver Skytrain operational costs of $1.94 million per mile and Ballard and West Seattle link operational costs of $5.35 and 4.68 dollars respectively, automation should reduce operational costs by at least 50%, a substantial value improvement long-term.

Table 4 below outlines three scenarios. Ballard and West Seattle as proposed (Table 3), Ballard to Judkins Park automated with grade separation in Interbay and Ballard to Judkins Park light rail at grade through Interbay. Note that the automated scenario assumes that grade separation through Interbay will not add any additional riders, even though speed improvements through that section should increase ridership by a non-trivial amount.

Ballard WS Table 42

Based on these assumptions the automated line would increase ridership per dollar by 12%. Of course without better ridership estimates for First Hill, the Central District, grade separated Ballard and frequency improvements with automation, this figure could be too low or too high. For instance, if the First Hill segment drew 30,000 riders instead of 24,000 we’d see a 22% improvement over the current proposal with a $4.32 subsidy per rider. This analysis also ignores the cost/benefit of bus transit improvements for West Seattle* or how the remaining ~=$400 million dollars budgeted get spent. The analysis also ignores the costs associated with the disruption associated with building at grade along 15th ave. All these factors indicate that the Green Line would be substantially more cost-effective than what is proposed.

If your disappointed about the at grade segment in Ballard or the lack of service to First Hill, note that the fundamental problem is that service to West Seattle requires using limited resources inefficiently, as a large portion of the West Seattle alignment is redundant and West Seattle. though dense, isn’t dense enough to overcome that issue. Moreover, if you want to find funding for complete grade separation or a tunnel under the Ship Canal, the way to do it is prioritizing First Hill over West Seattle. I’d also add here that if Sound Transit is a regional organization then First Hill, with high employment density and a key regional asset in Harbor View Medical Center, represents a regional destination in a way that West Seattle, with mostly residential density and no regional destinations doesn’t.


*At most times of day bus service to the portions of West Seattle is extremely fast. During midday Rapid Ride C is scheduled to get between Alaska Junction (California and Alaska) and Downtown in 20 minutes on average. West Seattle rail would get between the Junction and Westlake in about 17 minutes, with most of the time savings coming between Alaska Junction and Delridge, where the C line makes several additional stops. But at peak, the West Seattle bus routes are prone to crowding and congestion on SR-99 and/or the West Seattle bridge. The simplest fix to that problem is to bypass that congestion by making the left lanes of West Seattle bridge HOV 3+ and then building off ramps from those HOV lanes to the SODO busway. The buses would then connect with Link at SODO and potentially continue north to Downtown.


Freeway Transit and Aesthetics

In my previous post, I discussed the transit productivity of freeways and showed the benefits, in terms of efficiently moving lots of people, of ensuring free flowing bus transit on freeways. But in terms of rail transit in freeway corridors, the post only critiqued rail transit in so far as reliable bus transit on freeways is often far more efficient per dollar. However, there is a second common critique of freeway based transit, which is that it can’t readily generate long-term high ridership through transit-oriented development around stations. Theoretically, I believe this claim is largely bunk and this post will address why.

The first problem with the claim is that we have counterfactuals of high-density urban development adjacent to freeways. In Seattle, for example, the section of I-5 between Lakeview Blvd. and Yesler Way (i.e South Lake Union, Capitol Hill, Downtown and First Hill) are generally covered in dense buildings that are at least five stories tall. Moreover, move one more block away from I-5 and it is hard to tell that you are near a freeway, given noise levels and development patterns. Indeed, Seattle’s tallest building is situated in just such a location. Dense development can occur near freeways and dense areas near freeways are generally walkable up to one block away from the freeway itself.

Another potential downside with freeways is the amount of space they take up. Freeways are about a city block’s worth wide and this does cut into the walkshed around a potential station. But assuming that a rail station’s walkshed is 2,600 ft. (0.5 miles) and assuming a city block takes 260 feet, a freeway will take up about 1,352,000 sq ft. (260 * 5200) out of a total walkshed of 13,520,000* or about 10% of the walkshed. That’s a significant number but hardly a deal breaker. Indeed, the 3rd avenue stations of the Downtown Seattle Transit Tunnel lose about 12.5% of their walkshed to Elliot Bay alone. And yet these stations are projected to have some of the highest ridership in the entire light rail system. In short, in terms of developable land area, freeways only have a marginal impact on the potential utility of a transit station.

Indeed, it seems the principal issues around freeway transit concern the micro issues around walkability. It is generally very unpleasant to be near a freeway and in many instances frontage roads and off ramps around freeways make the area extremely difficult to navigate on foot. If people feel like it is an ordeal to get from the station to their destination, they will be far less likely to use the service. This aesthetic argument represents the core of the transit-oriented development argument against freeway rail alignments.

But making the walk to and from that station is a problem that can largely be fixed with two key design elements. The first key design choice is to build the station at an overpass where there are no on or off ramps. This way street design near the station can be oriented principally around pedestrians who may use the station (or just walk through the area).

The second key design choice is to lid the freeway with retail on either side of the overpass, like this lid the city of Columbus built over I-670. Adding human-centered uses where pedestrians exit the station can largely eliminate the discomfort associated with walking near a freeway. The overpass feels just like a normal street and not a freeway overpass. In addition, retail lids can be built fairly cheaply with cost estimates around $10 to $20 million, due to their minimal size and their being utilized by rent-paying businesses. With this relatively small additional capital investment (stations typically cost $80 to $100 million), the transit station can integrate more or less seamlessly into the urban environment. It’s also worth noting that smart lids’ have benefits for the neighborhood as a whole by providing better means for crossing the freeway. Overall, with smart station location and effective design, accessing a freeway based rail line can feel like accessing a non-freeway based line.


Freeway-based transit alignments have the benefit of readily available right of way and minimal neighborhood pushback due to noise pollution. Thus, they can be a very effective way to provide high capacity transit in a city that lacks it. But integrating freeway based transit into the city fabric and creating useful alternatives to car dependence requires effective design. Citizens and transit advocates should push hard for the addition of these design elements to freeway stations. In order to maximize ridership and rider experience, it is very important to ensure that planned freeway stations come with meaningful investment to maximize walkability in the area.

*13,520,000 = 2 * (2,600 ^2) (the area of a square with cross sections of length 5200).

Freeway Transit and Lane Efficiency

On Saturday, the Seattle Times editorial board wrote an editorial raising questions about the freeway-oriented nature of Sound Transit’s draft proposal. The editorial is rife with misleading or just plain old wrong information. But the board does raise a worthwhile point, which is that buses on freeways can be extremely useful transit that moves tons of people effectively. Let’s look at some numbers on freeway based bus transporpation.

Typically, transportation planners estimate that the average freeway lane can carry 1,900 vehicles per hour. Given an average vehicle occupancy of 1.2 persons per vehicle, that means 2,280 people can use a given lane in a given hour. (Note that this is in freeflow conditions. When congested, freeway lanes move less vehicles per hour). Thus, speaking abstractly, a freeway lane dedicated to transit would only need to carry about 2,280 people per hour for that transit lane to be a fairly efficient use of resources. All this is during peak hours when freeway space is scarce. At times when the freeway is well below capacity, the transit lane wouldn’t effect travel times in other lanes.

Fortunately, WSDOT has travel data on key freeway corridors so we can see just how many people utilize freeway based bus transit during peak hours. For example, on I-5 southbound at Northgate during the peak morning period (5am to 10am) the HOV lane carries 48% of all persons traveling. Of this 48%, at least 73.5% are transit riders meaning that the number of transit riders through the area is about 35% of total travelers during peak period. Given that there are five lanes southbound at that location, transit is carrying about 2.7 (35 / (52 / 4))  times as many people per hour as each general purpose lane.

Transit moves people along I-5 far more efficiently despite the fact that the existing HOV lanes that transit uses, though 11 minutes faster on average between Everett and Seattle, are still congested during rush hour, with about 12 to 15 minutes of delay over freeflow conditions. In short, there are enough HOV2+ car drivers to substantially congest the HOV lane buses use. Transit ridership would probably be at least somewhat higher if the lanes were converted to transit only lanes, ensuring reliable 60mph commuting for buses in the corridor and 12 to 15 minute travel time savings. Because transit moves so many more people then the general purpose means, converting HOV lanes to transit only lanes, at least during peak, would be a very effective use of limited freeway space.

Here is a more detailed cost/benefit analysis. At 35% (conservatively) of total I-5 users during morning peak, the benefit to the average transit rider would have to be about double the cost to the average non-transit rider from the conversion of the HOV lane to a transit lane. If the average transit rider is delayed by 15 minutes, then as long as the average driver was delayed by less than 7.5 minutes with the removal of the HOV lane society would unambiguously benefit from the switch. Unfortunately it is difficult to make definitive claims about how much additional delay drivers would face with the change, except to say that the 13% of non-transit HOV users would have an additional 11 minutes of delay, which means the remaining four lanes would have to have delays of less than 5.3 additional minutes for the transit lanes to be socially preferable.

It is worth noting here that the previous paragraph undersells the benefits of transit lanes on I-5. Reliable, time competitive transit tends to develop strong ridership and 12 to 15-minute improvements in travel time along with substantial improvements in reliability should convert many more riders to transit. Indeed, speed and reliability improvements are key reasons the Everett link extension would generate 35,000 to 43,000 daily riders or about 5 to 6 times as many riders as ride the current equivalent Sound Transit express bus routes.

This analysis just looked at I-5 southbound near Northgate during morning rush. But similar claims can be made about other HOV corridors in the region with only 3 of 14 HOV corridors meeting Washington State’s reliability standard of: “an average speed of at least 45 mph, 90% of the time during the peak hour of travel.”

The capital and economic justification exists today to implement fast reliable transit covering large swaths of the region by raising the standards of HOV lanes or simply converting them to transit only lanes. And if transit becomes extremely fast and reliable in the region’s freeway corridors, then the added value of building rail lines along I-5 to Everett and Tacoma, I-90 to Issaquah and the West Seattle Freeway to West Seattle pales in comparison to the Billions and Billions of dollars that rail would cost.

It is worth noting that there is some value from building light rail over having a bus rapid transit corridor, namely operational efficiencies at scale (trains are much longer than buses) and rail bias. But these benefits, particularly capacity, are not very important for the freeway rail corridors in the ST3 draft plan. Ultimately spending billions of dollars for additional rail along freeways in lieu of converting HOV2+ lanes into transit only lanes (or at least HOV 3+) represents an inefficient use of resources, incentivizes auto-usage over sustainable mobility, and ensures that excellent transit will reach these corridors 15 to 20 years later than it could, at great cost to travelers.

Sound Transit 3 and Cost/Benefits Detailed

Last week I published a post outlining ways to start evaluating the benefits of rail extensions in terms of costs and benefits. I used projected ridership, projected cost and a discount rate (because future benefits aren’t as valuable as present benefits) to derive an approximate subsidy per ride for a given rail extension. I emphasize approximate in part because a single number derived from a single ridership estimate for a single year can only provide so much information. But I also say approximate because I wasn’t as precise as I could have been with the costs and benefits. With Sound Transit proposing its draft Sound Transit 3 ballot measure, a decided to do a more detailed analysis of the costs and benefits of the proposal.

The basics of the analysis are the same. I still use Sound Transit’s ridership numbers and project costs and continue to use annuities to assess benefits over time. I increased my discount rate to 3% and assumed that the capital benefits last in perpetuity from the date the service is expected to open (these changes mostly cancel each other out). I also included annual operational costs into the analysis and I assumed that taxpayers pay taxes to cover project costs annually. Finally, I looked at scenarios where ridership was constant and where ridership increased by 0.5% per year. All ridership estimates use Sound Transit’s numbers, which estimate ridership in 2040.

For projects, I looked at all the rail projects (including infill stations) for which reliable ridership estimates existed, plus the two large BRT projects that are proposed as part of the ST3 draft proposal. This should cover well over 95% of proposed spending.

Before diving into the data, it’s worth defining what “subsidy per ride” means because it is the basis for analyzing the benefits of the investment. Subsidy per ride is the amount of social value we place on the average ride on the transit service. Since transit (or at least this transit) doesn’t pay for itself at the fare gates, we need to have some value for the amount that we are willing to subsidize a ride. This value comes from positive externalities such as emissions reductions and congestion alternatives. Coming up with an exact value is difficult, but farebox recovery rates for bus service provide a good litmus test.

Theoretically, bus subsidies should on average be higher than rail subsidies because buses also provide lifeline service, a social equity concern that rail systems don’t address. King County Metro has a 29% farebox recovery rate and fares ranging from $2.50 to $3.00. Sound Transit has a 22% farebox recovery rate and fares ranging from $2.25 to $5.75 for Sounder commuter rail. Given these numbers rail investments should probably have at least a 30% farebox recovery rate per dollar of subsidy though the case can be made for higher or lower subsidies.

In the tables below an $8.33 subsidy per ride corresponds to a 30% farebox recovery rate with $2.50 fare. Similarly, a $10 subsidy per ride corresponds to a 25% farebox recovery rate and a $7.00 subsidy per ride corresponds to a 35.7% farebox recovery rate. Unfortunately, Sound Transit does not provide more detailed fare information.

Here is the data on the net benefits and return on investment for each subarea and the region as a whole with dollar values in millions of dollars. Edit: Detailed formulas posted at the end of the post. For those not familiar with subarea system, the Sound Transit district is divided into five subareas and every dollar raised in a given subarea must also be spent in that subarea.


Net benefits (in millions of dollars) with 0.5% annual ridership growth.

Cumulative c-b table 5% growth net

Return on investment (1 = break even) with constant annual ridership.

Cumulative c-b table 5% roi

Net benefits (in millions of dollars) with constant annual ridership.

Cumulative c-b table no growth net

Return on investment (1 = break even) with constant annual ridership.

Cumulative c-b table no growth roi

The data tells a fairly sad story.

The most basic problem is that under less generous assumptions, the net value of the package is actually negative. That’s really troubling given that capital investments of this sort should have at least a 15% return on investment given the deadweight losses associated with taxes. And return on investment should probably be five to ten percentage points higher given that Sound Transit 3’s revenue will come from nasty regressive sales taxes. Only three out of the six scenarios meet the 15% threshold.

But the more harrowing issue is the hugely inefficient use of resources. Three of the five subareas (South King, East King and Snohomish) have a negative return on investment even with the most generous assumptions. There are lots of big projects here whose benefits do not come remotely close to covering their costs. Of course, some amount of pork to grease the wheels for a vote is inherent to the political process. But the amount of extremely wasteful spending in this proposal is rather shocking and far higher than Sound Transit 2. Notice all the red in the tables below, which show the data project by project. The net benefits for many projects are negative (and usually extremely negative) even under the most generous $10 subsidy per rider assumptions.

Table 1 c-b

Table 2 good c-b

If there is a silver lining to this analysis it is as a reminder for why rail investment in Seattle proper is so important. Even under more conservative assumptions, North King projects create over $2.7 billion dollars of value for the region and a 57% return on investment.

Overall, given these numbers and the amount wasteful spending in this project, I don’t see myself voting for it as it stands. Fortunately, the plan is not final and you can still give feedback to Sound Transit.


*EDIT: the actual specific formulas for calculating costs and benefits are:

Y = Projected Opening Year – Current Year

Benefit with .5% ridership growth

Benefit = (Subsidy * (Ridership / (1.005 ^ Y)) * 365 – Operational Costs) * (1/.025  – (1 – (1.005/.03) ^ Y) / .025)


Benefit with constant ridership

Benefit = (Subsidy * Ridership * 365 – Operational Costs) * (1/.03  – (1 – (1/.03) ^ Y) / .025)



Cost = Annual Paymnet * (1 1.03^25)/0.03 where

Sticker Price = Annual Payment * (1 – (1/.99) ^ 25) / -.01 (assumes tax base grows by 1% a year).

Assuming population increases by 1% per year reduces total cost by about 1.5% over 0 population growth.