… at a ridiculous price of US$4.99 through Monday, April 24. Buy it here, and you’ll be as cool as this dude.
… at a ridiculous price of US$4.99 through Monday, April 24. Buy it here, and you’ll be as cool as this dude.
Jacob Lynn is currently a data scientist at Booking.com, and was previously Chief Information Officer at public transit start-up Via Analytics.
Bus network redesigns have been making waves in the transit world over the past few years. The new Houston bus network represented a massive redeployment of resources, and early returns suggest that bus ridership is increasingly roughly as expected, though ridership is also subject to broader economic forces. Portland’s 1982 grid restructuring was critical to the early success of the new light rail system. But Barcelona’s recently redesigned bus network, the Nova Xarxa, has [despite this Human Transit post] received less attention outside Europe than it probably deserves. New research indicates that the network started inducing new demand as soon as it was deployed. Even though it is only partially complete, the Nova Xarxa is demonstrating the potential of transfer-oriented high-frequency bus networks for providing an anywhere-to-anywhere mobility solution for a city.
Prior to the redesign, Barcelona had a spaghetti-like tangle of routes with many stops, low speeds, and generally low frequencies. In other words, like most bus systems, it was biased towards coverage over ridership. Of course, in conjunction with the Metro network and the suburban Rodalies commuter rail, transit has a very high mode share in Barcelona overall. But city officials felt like they were not making the best use of their bus system. Could something be done?
Enter the Nova Xarxa. (NB: Nova Xarxa means “new network” in Catalan, and Xarxa is pronounced “sharsha.”) Carlos Daganzo developed a simple mathematical framework to model a “hybrid” transit network, which combines features of grid and radial networks. The model could be optimized to minimize a combination of transit agency and user costs, including travel and wait time. This abstract model was then applied to the specific situation in Barcelona to determine the target spacing between routes in the grid, spacing between stops on a route, service frequency, and other parameters of the network. It turned out that a grid-like network with very frequent service, stop spacing of about 400 meters, and about 20 lines would serve the city well.
Once these basic organizing principles had been determined, Transports Metropolitans de Barcelona (TMB), the city’s transit agency, got to work developing the actual routes. The resulting network has been remarkably faithful to the original grid vision. (The Nova Xarxa was previously discussed on Human Transit in 2010 and again in 2016.)
By design, a grid network depends critically on transfers between routes to enable anywhere-to-anywhere urban travel. Transfers between bus routes have a bad reputation among the public, to the point where there is a large academic literature quantifying exactly how awful it is to have to wait for the bus, particularly when connecting between routes. But in big urban metro rail networks, transfers between lines are commonplace and often only a mild inconvenience. The key difference is the amount of time you have to wait for your connection. Many metro lines run at intervals of 4 to 8 minutes, making the wait for the next train much more palatable. So, if the buses come sufficiently frequently, the thinking goes, the “transfer penalty” may disappear, and the system will function as a well-connected network rather than as a collection of individual lines. (Of course, the transfer experience differs between a metro system and a bus network due to other environmental factors, but generally speaking, if the wait time is short, those other factors will matter less too.)
The Nova Xarxa is designed with this principle in mind, with scheduled headways between 3 and 8 minutes for the entire system. The currently deployed Nova Xarxa routes all have scheduled headways of 6 to 8 minutes, and most current NX routes are intended to have shorter headways once the full network is deployed. Shorter headways are enabled by several factors. Increased spacing between stops, as well as dedicated bus lanes where space permits, have provided key speed increases. Some intersections have traffic signals which prioritize buses. New articulated buses were purchased that increased capacity and in some instances (e.g. line H12) enabled faster multi-door boarding. Removal of overlapping routes allowed redeployment of existing resources. But the network redesign was not intended to be cost-neutral, and some of the frequency increases have come from simply running more buses.
The Nova Xarxa has been deployed in four phases. In each phase, pre-existing routes that had been superseded by the new routes were removed or redesigned to focus on local service. Five routes were initially deployed in October 2012, five new routes were added in November 2013, and three more were added in September 2014. Three more were deployed in February 2016, but data from that period was not included in this report’s analysis. The full deployment of the Nova Xarxa will consist of 28 lines, and it is currently more than half complete. The detailed routes for the 12 final lines were recently proposed by TMB, and should be deployed during 2017 and 2018.
A group of researchers, including Hugo Badia of the Universitat Politècnica de Catalunya and Juan Argote and Carlos Daganzo from UC Berkeley, presented an analysis of ridership on the Nova Xarxa at the recent Transportation Research Board meeting in D.C. (As noted above, Daganzo worked with the city of Barcelona on the initial high-level network concept in 2010, but was not thereafter involved in the detailed design or deployment of the Nova Xarxa.) The research is publicly available as a working paper and is currently under review at TRB Part A. TMB provided the researchers with their key dataset: total bus boardings, broken down on a per-route, per-month basis, over the entire period of the new network. The dataset did not include detailed records of individual boardings, so the proportion of transfers could not be determined directly. But the phased deployment of the network allowed the researchers to use a clever technique.
Boardings on the Phase 1 routes generally reached a fairly stable level within a few months, but then jumped up sharply when Phase 2 was deployed, and then again when Phase 3 was rolled out. The authors infer that the increase in boardings on the Phase 1 routes was caused by riders who were transferring to and from the new routes. When the new routes opened, the old routes immediately became more useful, because they now provided access to more destinations with a short transfer. The researchers formalized this intuition into a simple statistical model, which allowed them to decompose each route’s ridership into two components: baseline demand for the route itself, and transfer demand for connecting routes.
So how much do transfers matter? The authors estimate that 26% of boardings on the current Nova Xarxa comes from transferring passengers — and once the entire network is deployed, they project that bus-to-bus transfers will represent 44% of boardings. This will be much higher than other major bus networks that overlay rail transit networks, such as Melbourne (16%), Boston (1.5%), London (13%), and New York (3%). (Note that this indicator is not always made public by transit agencies, and different agencies measure it in different ways.) Furthermore, comparing ridership on old routes to their new replacements suggests that corridor ridership has increased by 6% to 24%, due to a combination of increased connectivity, ease of use, and improved level of service. This figure should also increase as the rest of the network is rolled out.
Other factors have contributed to the success of the new network. In the early modern period, Barcelona, as the key city of Catalonia, was repressed by the centralized Spanish monarchy, fortified against revolt, and penned in behind its medieval city walls. Once these walls were removed in the mid-1800s, the city of Barcelona expanded dramatically beyond its medieval core under a strongly gridded street plan, known as L’Eixample. Thus, the idea of the “grid” has a strong resonance with the shape of the city for its citizens. Barcelona city officials have indicated that they believe that the disruptive Nova Xarxa plan faced less political resistance thanks to this intuitive preference for grids.
Beyond any speculative psychological considerations, Barcelona is a city of relatively spatially uniform population and job density. Within the city, there is no strong central business district generating demand for highly radial transit. Furthermore, the city is geographically constrained by mountains to the northwest, the Mediterranean to the southeast, and the Llobregat and Besòs rivers on the other two sides. Thus the overall urban density is quite high. Demand for space-efficient modes in Barcelona is intrinsically high and isotropic, making the Nova Xarxa a natural fit.
These results should not be too surprising. But it is rare that the real world provides us with such a clear-cut opportunity to test the principles of network design. Barcelona’s experience strongly suggests that a dense network with sufficient frequency for painless transfers can unlock anywhere-to-anywhere travel.
The authors of the original analysis, Hugo Badia, Juan Argote, and Carlos Daganzo, provided very useful feedback on early drafts of this article.
We’re now at the end of a 1.5-year study to help Silicon Valley’s local transit agency, VTA, rethink its bus network. I explained the thinking, and public conversation, that led to the draft final plan in this comprehensive post, and also showed how it compares to the existing one. The final plan looks pretty much like the draft one with a few additions and adjustments.
Here’s the new network. Download a sharper copy here.
The plan is expected to be implemented when the BART extension into the area opens next year.
We’re very proud of this work, and of all the people — in the transit agency, other local governments, and the broader community — who worked with us design and refine it. With this plan, 150,000 more people will have access to all-day high-frequency service, as will 160,000 more jobs. A huge expansion in weekend service is planned. A new rapid bus line is added. (Again, more on the details here.)
Most importantly, more people can get to more places sooner, so that they can do more things and have better lives. And that’s what we’re all about.
Every day, I get at least one email that looks more or less like this:
I hope this note finds you well and thanks for your time in advance. My name is X and I am studying/working at Y. I’m writing something exploring the general transit topic of Z, and after browsing your blog I know you would be a great person to talk to. Is this something that you would be open to chatting about ?
I am a friendly but busy person who gets lots of these emails. I enjoy talking about interesting issues with interesting people, and will spend some unpaid time doing that.
However, if you want a bit of that unpaid time, you need to offer me one of three things:
If you ask me a general question that requires me to explain things that I’ve explained in writing, and that I’ve said 1000 times in presentations, well, it’s interesting for you but not so much for me. I repeat myself all the time on the job, and I’m happy to do it, but it’s how I spend my time off.
That’s what I did when I was in your shoes, as a transit geek and advocate with no relevant connections, job, or influence. It worked.
So if I didn’t respond to your email, this is probably why. (Though sometimes, I admit, I’m just too busy.)
We all need to practice reading and refuting arguments of the form: “Central government should focus on big national issues, like highways, instead of local needs, like transit.” It’s become one of the most common ways for people to dress up their preference for roads over transit as an expression of a consistent policy.
For the most part, transit systems are local matters. Using federal taxes to collect money from the whole country and then send it back to each local transit system is a terribly inefficient way to raise money for transit and is also inherently unfair as different locales receive back either more or less than they paid in. The only reason to rely on federal funding for part of the cost of local transit systems is that it helps local politicians by keeping their local taxes and transit fares lower.
This common practice of using federal funds for local projects in order to hide the true cost should be stopped. The federal government should pay for the things that are truly national in scope (like the interstate highway system). This type of federal spending for local needs encourages too much government spending by making higher costs easier to sell to voters. The federal government should stop being used as an enabler to higher local government spending.
That’s University of Georgia economics professor Jeffrey Dorfman, in Forbes yesterday.
Dorfman seems to invoke the principle of devolution — the idea that government actions should be planned and funded at the lowest level of government that can deal with the issue within its boundaries. It’s often stereotyped as a conservative idea in the US, but it shouldn’t be. In the UK, for example, it’s mostly the leftist cities who are rebelling against over-centralization of planning power in Westminster. The same idea is gaining force in US urban policy, as cities chafe under rule by central governments that care only about suburbs and rural areas. Everyone prefers to deal with more local governments that are easier for a voter to influence, so this is a space of potential left-right agreement that deserves more discussion.
But the notion that highways are national while transit is local? This makes sense if you’re a motorist, but here’s what happens when you press on it:
— Jarrett Walker (@humantransit) April 3, 2017
@humantransit Because it is possible to drive on the interstate from state to state (as truckers and some drivers do), while subways are local. Period.
— Jeffrey Dorfman (@DorfmanJeffrey) April 3, 2017
If the test for Federal funding is that a facility is used for interstate travel, fine, but this suggests a coherent interstate network of roads and rails scaled for the interstate demand only. Then, all additional capacity and upgrades needed for travel within a state would be state and local costs. What would this mean?
Nobody would propose this policy, but only for the boring reason that it’s biased toward multi-state metro areas: The Northeast wins big while California and Texas lose. But if you could control for that, this would be a coherent principle of devolution such as Dorfman seems to be advocating.
But our car-first friends never make that argument. Instead, they just handwave about how of course highways are naturally national while those other things are local. In fact, the distinction between interstate and intrastate doesn’t line up at all with distinctions among road, rail, maritime and aviation modes — either passenger or freight.
This is why you should see through these familiar arguments, and recognize them instead as sheer claims to hegemony: “We road people are superior, so of course money should be spent on us — including giving road-based services a leg up in competition with other modes.”
The former Australian Prime Minister Tony Abbott liked to make the same argument:
“We have no history of funding urban rail and I think it’s important that we stick to our knitting,” the Federal Opposition Leader declared. “And the Commonwealth’s knitting when it comes to funding infrastructure is roads.”
In his autobiography, Abbott wrote about how driving a car is a quintessential Australian experience, a key to the national character. He is also known for an extreme social and cultural conservatism that is toxic in inner cities. So even among those who agreed with him, Abbott’s comments were widely recognized as an expression of a cultural agenda, not an economic one. While nodding at devolution, he was really saying that road people like him are superior to those urban transit people, none of whom will ever vote for him anyway.(1)
When you see arguments like Dorfman’s, that, I’d suggest, is what you should hear. Devolution itself is a powerful idea, but we’ll never have a clear conversation about it if it’s only used to make claims of superiority.
(1) Abbott was deposed in 2015 by Malcolm Turnbull, an urban conservative from a wealthy part of Sydney. Turnbull dumped Abbott’s roads-first view, stressing instead that Federal transport investments would be multimodal. Despite its powerful rural interests and cultural identity, Australia has a strong bipartisan consensus that its national economy depends on the functioning of its cities.
On average, across the 14 metros analyzed, one Transit Score point can increase the price of a home by $2,040. But the price premium varies widely from metro to metro.
That variance is a problem, though. For example, a Transit Score point gains you 1.13% on property values in Atlanta but counts for nothing in Orange County, California. When you see this kind of variance, you should suspect that other factors are more significant than the one being studied. So this supposedly pro-transit Redfin piece can actually be used to argue that transit isn’t all that important, or at least that when transit is important, it’s because it echoes something else that matters more.
But we should explore a simpler explanation: Maybe transit is relevant, but Transit Score isn’t.
I explain what’s wrong with Transit Score here, but the bottom line is that Transit Score has nothing to do with where you can get to on transit. Transit Score is about how much transit is nearby, and whether it’s cute or sexy, but not at all about whether it’s useful. In this it’s much like the way the real estate industry evaluates static civic amenities, like schools and parks, whereas it should be more like the way the same industry evaluates road access, i.e. by caring how fast you can get to places. More here.
This is important because when you publish results with such huge variability, you tip off smart people that you may not be looking at the right explanatory variable. It’s easy to look at these results and assume that transit isn’t what matters. But maybe it’s Transit Score, not transit, that’s the distraction.
If you want a quick assessment of the usefulness of transit at a location — say, a place where you’re planning to live, locate a business, or invest — what do you want to know?
The tool realtors know is Transit Score, a two digit number (like its elder sibling WalkScore) that supposedly gives you a quick hit of meaning about how good transit is. Transit Score was invented by WalkScore.com, which has since been eaten by real estate giant Redfin.
But here’s how Transit Score is calculated:
To calculate a raw Transit Score, we sum the value of all of the nearby routes. The value of a route is defined as the service level (frequency per week) multiplied by the mode weight (heavy/light rail is weighted 2X, ferry/cable car/other are 1.5X, and bus is 1X) multiplied by a distance penalty. The distance penalty calculates the distance to the nearest stop on a route and then uses the same distance decay function as the Walk Score algorithm.
So in short:
These problems arise from an unthinking real-estate world view in which transit is a feature of a site, like parks. In fact, transit quality lies in a site’s position in a network, and it is the network, not the immediately proximate features, that delivers all valuable transit outcomes.
Imagine if an Auto Score were constructed like Transit Score: It would give no value to average travel times to actual jobs around the region, but would be very interested in the square feet of paved roads found within a very short radius around the site. It would also care about the aesthetic quality or “look and feel” of that pavement, and might give some weight the local speed limits.(1)
A few years ago, when Transit Score first rolled out, I discussed it ” WalkScore’s Matt Lerner, expanded on this very critique, and suggested a better (though computationally intense) approach. It involves aggregating the content of travel time isochrones – effectively “maps of your freedom” — over all likely destinations from any residence, so the two digit score is actually a percentage, a composite of answers to the question “What percentage of jobs, retail, etc can you get to in __ minutes, on transit, from here?” It needs refinement, but that’s the only truly factual measure of access that could be reduced to a two digit number — one that would actually mean something.
(1) Yes this is an inexact analogy. Transit Score does begin with frequency, which matters a lot, and the impossibility of translating frequency into automotive terms is one of the main reasons it’s so poorly understood, especially in North America.
In 2012, I worked with the transport authority of New Zealand’s largest metro area to design a new bus network for the fast-growing region. A key idea was to replace a tangle of infrequent services with a simpler, more frequent network. People would need to change buses a bit more, but they’d be able to get to more places sooner
Small parts of this network were implemented in 2015-16, but the first big slice was the South Auckland portion, which I discuss in detail (with maps) here.
South Auckland is about 1/5 of Auckland. North Americans would recognize it as “inner ring suburbia”. It has areas of very significant low income and disadvantage, but there are many barriers to walking, and the maddening, discontinuous street pattern makes it hard to draw remotely straight bus lines.
Auckland Transport implemented the South Auckland network at the end of October 2016, so it’s been running for just over four months. Many network changes don’t show any benefits that early, but we’re getting a significant surge here. From the March 2017 Board Report (starting on page 32):
Total South Auckland boardings in February (the number of times someone got on a bus or train) were up about 19% from the previous February, when normalised — that is, adjusted to reflect different numbers of weekdays per month (and days in the month, in February’s case). In this chart, the bars are raw data but the lines are normalized.
But this chart is more helpful:
Again, the new network went in at the end of October, so it’s clearly the cause of the sudden jump.
The growth in transfer boardings is almost 3/4 of the growth in boardings, so only about 1/4 of the growth in boardings is the growth in new passenger journeys [“normalised trip less transfer growth,” the yellow bars]. So the growth in passenger journeys is around 4%, not 19%.
(Yes, the lack of consistent counting of passenger journeys [“linked trips” in US parlance] is one of several things wrong with most ridership reporting. A big jump in boardings can be just the jump in transfers, which means the network isn’t really serving more passenger trips. Many transit systems have trouble counting transfers — indeed, some fare systems leave no record of them — and there are many estimation methods out there, s0 the reporting is hard to standardize.)
Note, too, that passenger journeys are growing at a steady clip after dipping down in the first month of the new network. This is routine. It takes time to discover the new network’s benefits, and for new passenger trips to appear as a result. However, the need to transfer to complete formerly direct trips happened at once, so a sudden jump in transfers, and thus boardings, is understandable.
So if you were comparing this to other ridership figures, which tend to be about boardings, we’d say we’re up about 19% just four months in. By contrast, the regional model in Houston suggested our redesign there might achieve +20% in boardings after two years (and net of external effects that have, in fact, utterly confounded the numbers.)
Four months in, a 4% growth in passenger journeys is spectacular. This is the sort of growth I might hope for after a year. And the trend-line is very promising!
Our tiny firm is delighted to announce that we’ve hired our first East Coast senior planner and project manager.
He’s Scudder Wagg, a versatile transit planning consultant formerly with Michael Baker International. Scudder has been embedded with us for a year, working on the Richmond Transit Network Plan, so he already knows everything we do better than we do ourselves.
He is based in Richmond for now but he expects to move up to the DC area to establish a full East Coast office.
It’s now pretty clear that transit ridership is falling in many US cities. Why?
I don’t know. (Don’t trust any pundit who never says this.)
But journalists are asking me this and I need an answer. Laura Bliss’s recent piece in Citylab really captures the problem. It’s a smart read, but in short: Bliss interviewed a bunch of experts on this, including me, and she got lots of smart speculation, mostly grounded in anecdotes. (“Pick a Culprit” was her sub-headline).
Everyone seems to agree on the same long list of culprits.
And I would add a couple of others to the list.
The problem is, we really don’t know the relative importance of these things, and neither does anyone else who’s speculating in the media.
Bottom line: We need research! Not the sort of formally peer reviewed research that will take a year to publish, but faster work by real transportation scholars that can report preliminary results in time to guide action. I am not a transportation researcher, but there are plenty of them out there, and this is our moment of need. Here are my research questions:
One more note: It’s easy to analyse this “bus vs rail,” because that’s how the National Transit Database is structured, but nobody knows if that’s the real distinction that matters. As Laura Bliss’s piece notes, rail ridership and bus ridership are not trending any particular way relative to each other — a good hint that this is just the wrong place to look for an explanation.
I don’t pretend this is easy, but it’s needed. Scholars! Come to our rescue!