The BusGraphs Project

This is an updated proposal for transit service in Seattle that exceeds King County Metro’s definition of frequent service on all routes 24 hours per day, 7 days per week. Compared to its predecessor, it incorporates some changes to mitigate potential overcrowding, and, more importantly, uses a corrected budget of in-service transit hours. Correctly assessing, and holding to, this budget is critical for this proposal. In-service hours drive agency operating costs. As tempting as it is to imagine what a better-funded King County Metro could accomplish, I fear that not holding to a budget would push a proposal that is already ambitious and challenging into the realm of the totally impractical. As the budget of in-service hours is about 12% less than previously thought, the resultant route map looks sparser. Some bus routes that many people use daily would disappear, without direct replacement, under this proposal.

Removing existing routes is bound to be unpopular. Why consider it when running routes with uniform headways throughout the day and night is unheard of among transit agencies? I assert that their choice not to do so contributes to automobile dependence. I made this argument in more detail when I debuted the initial proposal. In short, if a person fears that relying on public transit will eventually leave them in a situation where they desperately need to make a trip, but can’t in a reasonable amount of time, they will prioritize purchasing a car. Once a person owns a car, the marginal cost of each use is low, compared to the fixed acquisition and maintenance expenditures. It will get used even for trips that could be reasonably made with transit. The increased congestion undermines transit that shares right-of-way with private vehicles. It can even hinder attempts at constructing dedicated right-of-way, since construction decisions will favor minimal traffic disruption over optimal station placement. As unusual as uniform frequency may seem to a transit planner, I believe that it is a necessary ingredient in a transportation system where fixed-route public transit is intended to largely supplant, not supplement, private vehicle use.

Due to a software error, the in-service time amounts computed for transit networks in previous posts are inaccurate. Posts where an access measurement is used on its own are not affected. When access is expressed in terms of the amount of in-service time—whether for the entire network or an individual route—this quantity may be incorrect. In specific, these posts are impacted:

• Seattle’s Transit Agencies Can Do Better
• How to Cut Service by 22% and Boost Access by 13%
• A Seattle Transit Restructure by the Numbers
• The Aftermath
• Seattle Could Have 24/7 Frequent Service; King County’s Priorities Seem to Lie Elsewhere
• The entire Route Productivity series

Due to a computational error, the data and conclusions in this post may not be accurate.

This installment of the access-based route productivity series focuses on four routes that serve Seattle’s Capitol Hill neighborhood, but are otherwise quite varied. Three of these routes skirt downtown, but one passes through Capitol Hill on its way there. Two meet Metro’s definition of frequent, one runs less frequently but all day, and one is the rare example of a peak-only route not oriented around downtown. The variation continues in the positions of routes 8, 9, 11, and 60 within Metro’s ridership-oriented route productivity measurements, and my access-based ones.

Decisions in public transit are often framed as tradeoffs. Should transit service cover a broader area, or should fewer routes run more frequently? What times of day, or days of the week, should see the greatest allocation of service? Rarely will one outcome be superior to another in all ways, for all people. This is the unfortunate reality when limited funding is a hard constraint.

An access measurement comparison, in its most condensed form, doesn’t present an obvious tradeoff. The consequences of any decision are rendered in the form of a single score. Good decisions increase the score, bad decisions decrease it. Of course, this is an oversimplification. The overall access measurement is the composition of many scores. An agency may achieve its greatest overall access by concentrating all of its routes into a section of its service area, but those who must leave that section will be justifiably upset.

The restructured transit network for Seattle that I produced—with uniform frequency meeting or exceeding King County Metro’s definition of frequent service on all routes, all day, every day—increased overall access while using no more in-service hours than the existing network. I nevertheless sought to be cognizant of how this would affect access throughout the city. While some parts of Seattle would see a decrease in access, the losses would be neither severe nor widespread. That still doesn’t cover every way that a restructure could disparately impact riders.

Due to a computational error, the data and conclusions in this post may not be accurate.

Measuring a route’s access-based productivity involves creating a hypothetical transit network in which the route doesn’t exist. For the two routes in this installment of the series, elimination is anything but hypothetical. In preparation for the Lynnwood Link extension, King County Metro will be revising its transit service in North Seattle and Shoreline. Routes 20 and 73 are technically being replaced by new routes 61 and 77, not deleted. In reality, significant portions of their paths through Seattle are losing transit service entirely.

In my 12 years in Seattle, I’ve observed that Metro is reluctant to entirely remove transit service from corridors. The route serving a corridor may change, based on a desire to connect neighborhoods to different resources (typically new Link stations), but total elimination is a rare proposition. When initial plans have included route deletion, they are often walked back, at least in part. The cuts to routes 20 and 73 have survived the full public comment and county council approval processes.

Due to a computational error, the data and conclusions in this post may not be accurate.

When I last looked at access-based route productivity, I found that a sample of Metro’s conventional bus routes nearly-categorically outperformed a selection of trolleybus routes. The type of vehicle wasn’t the only difference between the two groups, though; they each had a geographic bias. The trolleybus routes all serve Queen Anne Hill; the conventional buses connect downtown Seattle and neighborhoods to its north by way of the Aurora Bridge.

I previously warned about the negative consequences of using mode to judge the effectiveness of transit routes. But the trolleybus routes considered to this point are less valuable than the conventional routes. The reasons for that are, plausibly, due to the infrastructure that underpins them. It would not be wise, though, to rely on an incomplete and skewed result like this to make sweeping conclusions about trolleybuses as a mode. An assortment of King County Metro’s routes run under trolley wire, and there’s nothing about that that condemns them all to ineffectiveness. To demonstrate this, I calculated the same set of access-based route productivity metrics for all of the remaining trolleybus routes.

Due to a computational error, the data and conclusions in this post may not be accurate.

The routes in this update of the access-based route productivity series all cross the Lake Washington Ship Canal using the Aurora Bridge. Routes 5, 28, and the E Line share a common path out of downtown Seattle, cross the bridge, and then diverge. They are much more straightforward than the routes in the last installment; they largely lack the intra-route variation, twists and turns, and overlaps of the previous batch. There is a longer version of route 28 that runs during peak commute times. Aside from that, these routes basically correspond to one sequence of stops, in contrast to the aforementioned route 3, and its mess of variants.

Another thing that differentiates these routes is that they are run with conventional buses, rather than the trolleybuses used on the routes¹ that have been analyzed thus far. Overall, I think that vehicle type—referred to as “mode”—gets overblown in public transit planning. Planners associate different rider behaviors with mode, rather than characteristics like frequency or dedicated right of way. In some cases, the mode does influence that nature. There is a stark difference in the access-based route productivity measurements between this batch of routes and the previous ones, and perhaps something about the infrastructure that underpins them does play a role.

When trying to solve a complicated problem, I find it useful to ignore obvious constraints at first. It’s obvious that a transit vehicle cannot hold an infinite number of people. Yet when I proposed a redesign of King County Metro’s transit network in Seattle with frequent, 24 hour, seven day per week service, that is exactly what I did. I find that being confronted with a large number of constraints early on encourages an overly conservative end goal.

Beyond the objective of uniformly frequent service, only one constraint governed my redesign. I did not want the new network to increase the number of person-hours required to operate the system’s transit vehicles. This is the predominant expense of transit agencies. Keeping this net-neutral separates a pragmatic proposal from a fantasy. All other constraints could be sorted out later. Thinking in this way produced a network that doesn’t resemble typical transit service, though a rider could easily see the benefits.

Due to a computational error, the data and conclusions in this post may not be accurate.

I’m continuing to explore access-based route productivity measurements by examining four routes that, like route 1, serve Seattle’s Queen Anne neighborhood. Routes 2, 3, 4, and 13 make their way up its eponymous hill. These are some of the quirkiest routes in King County Metro’s system. The former three are putatively long routes connecting downtown Seattle with mostly-residential neighborhoods on either end, but run a variety of shortened trips. Meanwhile, route 13 is linked with some, but not all, abbreviated route 2 trips. It might be more pragmatic to think of these as six shorter routes with a common trunk downtown, but that’s not how Metro treats them. It evaluates the productivity of each route in its totality, so I will do the same. How do these routes compare when it comes to access-based route productivity measurements?

Due to a computational error, the data and conclusions in this post may not be accurate.

I received a package from Amazon the other day, and I noticed something hidden under the shipping label. My first full-time job was writing software for its warehouse operations, and I had a passionate love-hate relationship with it. I had to take a closer look.

PackTypes! I remember those! Without delving too much into the minutiae of Amazon’s warehouse operations, they’re broad categories of packaging. Back then, I saw their use in enforcing appropriate packaging as clunky and inflexible. In my view, the solution was to relegate the PackType concept to the dustbin of history, in favor of granular packaging instructions that would impose restrictions on a shipment by shipment basis. I wrote design documents for this. I navigated the web of systems that referenced PackType and proposed migration plans for each one. I advocated for it as an organizational priority whenever I had the ear of management.