From Vuchic's Transportation for Livable Cities, what does it take to move 15,000 people/hour using different modes of transport:
The remarkable thing is that the 7 lanes of freeway in each direction have zero extra capacity at that bandwidth, while the single track of rail rapid transit has, theoretically, at least another 66% to spare (see whole table).
A fantastic interview with Fred Salvucci [PDF], one of the premier transportation engineers and policy-wranglers of the latter half-century (and a prof in the program at MIT that I'm applied to). The subject is the Big Dig, which, amazingly turns out to be an "anti-highway project." What I didn't know was that the massive upgrade to Boston's mass transit system was actually a key part of the Big Dig, in terms of funding, politics, and project sequencing. This is certainly one of the most clearly stated presentations I've read of why it doesn't make sense to rip highways through city cores or neighborhoods, and what it takes to implement alternative solutions. For example:
Q: Do you remember your major victory when Frank Sargent publicly reversed his policy on highway building?A: Yes, of course. In many ways the most thrilling moment in the history of the antihighway fight was when we won. And then Governor Sargent went on television and said, basically, he had been the public works commissioner who had fought for the inner belt earlier in his career and, as governor he said it was a mistake and "I'm going to admit that mistake and stop the program and we're going to shift towards public transportation." I mean it was thrilling. It was thrilling for us that had worked hard on it, but also, in fairness to Sargent how often do you see a public official who gets up and says, "I was wrong"? I mean it was an incredibly courageous hing for Frank Sargent to do, and I'm a Democrat. I don't say many good things about republicans. But he was a great man. I mean he had worked for this program. He always had an environmentalist bent to him. [A] lot of people do political analysis as to why he did this or that. I think he just believed what he said. "This was a mistake and we're going to go in a different direction." It was a thrilling moment in the history of it.
And then we actually moved in that new direction. I mean we shifted the funds, partly under Governor Sargent, partly under Governor ukakis. Those monies that were going to go into destroying those neighborhoods or building the highways were shifted into refurbishing the commuter rail system, extending the Red Line, relocating the Orange Line, basically rebuilding the public transportation infrastructure of the city. That came out of that decision and another component of the same decision -- you can go check that speech that Frank Sargent gave -- was that the only highways that would continue to be studied within Route 128 would be the depression and widening of the Central Artery and the extension of I-90 over to Logan in an additional tunnel, the two components that are today called the Big Dig. Those were really part of that, if you will, anti-highway -- "anti-highway's" probably the wrong name -- pro-city decision that was made by Frank Sargent to shift towards a transportation strategy that would build the city instead of destroying it.
And a major component of that was, stop building destructive roads. Another major component was, put a lot of money into improving public transportation, and the third component that we're seeing built now is, take the existing Central Artery that's there and fix it. I mean fix it both from a transportation point of view, because it doesn't work, but also fix what it did to the city by etting it underground and knit the city back together again. That was a very thrilling moment in my life, when Sargent did it. And I've always respected him a great deal because of the courage that it took to do that.
Also, an as-of-yet unread interview with David Luberoff [PDF], co-author of the as-of-yet read great book Mega-Projects: The Changing Politics of Urban Public Investment.
One key to the No. 7 extension’s fast progress involved the financing. Mayor Michael Bloomberg and Deputy Mayor Dan Doctoroff, champions of the project, recognized early on that the 7 extension would go nowhere if it had to compete for funding with the Second Avenue subway, connection of the Long Island Rail Road to Grand Central Terminal, airport rail access projects, a new tunnel from New Jersey, replacement of the Tappan Zee Bridge and other mega projects. Thus, they developed a novel funding method. The bonds issued last month, and another set of bonds to be issued in several years, will be paid off using payments made to City Hall in lieu of taxes by new residential, retail and office development on the West Side, payments for development rights in the eastern part of Hudson rail yards themselves, and from other taxes collected from the area. Having its own funding source was immensely important to bringing the 7 extension along.This isn't really that new a concept for transportation funding, just in America! It is generally referred to (eg in Cervero) as Value Capture. And what, putting the Gowanus Expressway underground?
Old school. What surprises me most is how equanimous it is towards all the modes -- car, subway, bus. Check the researchers at the end. Could be me some day...
As part of my internship at the Regional Plan Association I was asked to research the applicability of mesh networks to congestion pricing for New York City. What follows is the result of several days of reading, surfing the web, talking on the phone, and stroking my chin. It assumes some knowledge on the topic, most of which can be found in descriptions of London's Congestion Charge, upon which any scheme in New York is likely to be based.
Continue reading "Congestion Pricing, Positioning, and Meshed Wireless Networks" »
In its 1996 Third Regional Plan, the Regional Plan Association describes a rapid transit line in Brooklyn, Queens, and the Bronx that could be built almost entirely on pre-existing rail rights of way and would connect with at least twenty existing subway lines. The so-called ''Triboro RX'' (''TRX'' for short) presents a unique opportunity to provide mobility and accessibility to New Yorkers living or working within these three boroughs, at a fraction of the cost of most transit projects of similar size. In my part-time internship at the RPA, which ends today, the lion's share of the work I have done has focused on fleshing out the idea of this line.
Working with the singular Jeff Zupan and his former sidekick Alexis Perrotta, I helped to develop a possible alignment for the Triboro RX, and a crude estimate of what levels of initial commuter ridership one could expect to see if it were built. The fruits of this labor can be seen on the web at http://transit.frumin.net/trx/TriboroRX (including sections on the alignment, our data sources, the demand model, and detailed results). There I describe in detail how the line and its stations are laid out and how we made our estimates. At the end of the day, we can comfortably say that at least 76,000 New Yorkers (including 32,000 diverting from other modes of transportation) would use the Triboro RX to get to and from their jobs every day. This number that is quite competitive with many existing lines, and without ever touching the island of Manhattan.
At the heart of our ability to make this estimate is the Journey-to-Work data published by the census -- counts of commuters between every census tract and every other census tract in the city. Given these flow data, the shape of the subway network with and without the Triboro RX, and a rough model of how people make travel decisions on public transportation, it's not so hard to guess which subway riders would use a new transit line if it were built. Estimating new transit riders is more nuanced, but we did our best with limited resources.
This study of the Triboro RX has, for me, been much more than a semi-traditional transportation modeling exercise. I took it as an opportunity to get intimately familiar with the state of the art in Open Source mapping and GIS software, including PostGIS, GeoServer, and OpenLayers. These pieces represent a full network-enabled stack for, respectively, storing and manipulating, mapping and presenting, and client-side interfacing of spatial data. I don't think they are quite yet usable by the non-hacker, but I wouldn't be doing this work if I didn't think that my computing skills brought something special to the table. That said, I encourage you to check out the following:
Now, it wouldn't be a perfect project to do, for free, when I should be saving money for school, if it didn't also involve getting my hands dirtier than they already do from all the crumbs in my keyboard. It seems absurd to talk about planning a transit line without actually having visited the areas it would connect. Having synced the clocks on my GPS device and digital camera, I twice explored the Triboro RX right-of-way and its environs from Flatbush to Bay Ridge, in Brooklyn. The results are viewable either in Google Earth or directly on the web. What really struck me was the diversity of neighborhoods -- Flatbush, Ocean Parkway, Borough Park, Sunset Park, Bay Ridge -- traversed by the Triboro RX in less than a third of its length. Continuing on, it runs through East New York, Brownsville, Cypress Hills, Middle Village, Jackson Heights, Astoria, and Mott Haven. You could eat your heart out while getting from Brooklyn to the Bronx, skipping "the city" entirely.
Finally, no contemporary New York transportation project is complete if it doesn't some how tie into Congestion Pricing. In terms of providing mass transit to unserved communities in the outer boroughs, methinks this graphic speaks for itself:
PS Please forgive me, I know these maps need legends for the quantitative parts. It's all a big hack, trust me!
PPS The interactive web maps work much better in FireFox than Internet Explorer. Save your soul and get a real browser.
[err, so now NY may get it together on congestion pricing, but the train of thought is relevant nonetheless]
While usually calling something a zero-sum game is a bad thing, in this case I mean it positively. The $500M for a congestion pricing pilot that New York has lost may still lose would go to somewhere else like Dallas, San Diego, Atlanta, San Francisco, Denver, Miami, Seattle or Minneapolis. I am a New Yorker born and bred, and am as disappointed as anyone about this, but I think in this case we all may be suffering from a slight case of New-York-is-the-center-of-the-world-itis.
None of these other cities have nearly the mass transit system that New York has. Probably combined their mass transit systems don’t carry half the passengers ours does, and most people living in those places think of cars as an absolute necessity for practically everything they do. In a broader sense, it could very well be an overall net positive that the congestion pricing pilots happen in other cities. Perhaps those places will make incremental progress in shifting people out of cars and more importantly, changing peoples' value systems when it comes to cars vs. other modes.
If we are really lucky, this could be the first wave in a national shift towards more rational thinking about transportation, which would definitely benefit NYC in the long term. In truth, I'm a lot less worried about NYC than I am about other cities and the country/world as a whole, so I wonder if it doesn't hurt to at least imagine the possibility of some greater good coming from Albany's (seeming) ineptitude.
Or at least, the capacity?
The first strategy for adding additional housing outlined in Mayor Bloomberg's 2030 plan is to pursue transit oriented development. In simple terms, dense development around transit stations and hubs. However, the plan also describes capacity issues that our transit system faces today and will face in the future. So, we should build all our new housing clustered around a transit system already reaching capacity? Hrmmm...
Looking at subway ridership in a long term context, it's pretty clear however that while some lines may be quite crowded today, the system as a whole is substantially below the highest usage levels it has supported historically. On the whole, we have recovered from a nadir of 915 million trips in 1977 to 1.5 billion trips in 2006 -- about the same as in 1952.
We all know that commuters from Williamsburg and the Upper East Side are suffering, but the question remains -- are there parts of the city where subway usage is substantially below levels that have been supported in the past? Comparing each station's 2006 annual ridership to levels in 1952 yields the following map, where red indicates a net decrease over the last 54 years (and thus, theoretically, excess capacity):
This analysis of course doesn't account for the fact that bringing the South Bronx back to historical levels would make the problems on the Lexington line even worse than they are today, but it at least gives a sense of what areas could accept housing growth around subway stations if the most pressing line-level capacity issues were resolved.
What if we want to look at each station's or line segment's pattern over time? As they say here in London -- "watch this space" (and think sparklines).
[Technology Shoutout: most of the work for making the above map was done by the ever-more-brilliant open source PostGIS and GeoServer packages.]
A genius I know once wrote an article that some say brought the distinction between packet-switched and circuit-switched networks into the popular consciousness. In the decade or so since, we have seen packet-switched networks take over the world, and unfortunately some people find themselves tempted to abuse this bit of history in arguing related points. The gist of it will always be something to the effect of: "the thing I support is like Packets, the other thing is like Circuits, and since we all know that Packets beat Circuits, I must be right." (This is not unlike how many in my extended family will take anything they think is sufficiently bad and compare it to Hitler.)
For example, a recent piece (of what I don't know) by Stephen Fleming of the Georgia Public Policy Foundation, entitled In Transportation and in Technology, Packets Beat Circuits, starts off "Why are so many mass transit policies doomed to failure? Because packets beat circuits. Let's explore an analogy."
You can imagine where it goes from there ("cars are like packets, mass transit is like circuits, so cars are better"). The guy claims to have worked in digital communications for 10 years; I wonder if he's just bitter because he was on the wrong side of the packets vs circuits debate.
For the sake of all 6 people likely to read this, I hereby debunk this terrible analogy:
The fundamental aspect of a circuit-switched network, as stated in the first sentence of the Wikipedia article on Circuit Switching is that it "establishes a dedicated circuit (or channel) between nodes and terminals." That is, the bandwidth for the flow is reserved end-to-end for the life of the circuit. Traditionally, when I make a phone call, part of the 'space' on a bunch of copper wires connecting where I'm calling from to where I'm calling to is reserved even if no one is saying anything over the line.
Clearly a road network is not circuit-switched -- when you start out from your house you don't have a dedicated lane all the way to your destination (if you did, I might just own a car). In a circuit-switched transit network, not only would I have a seat on one R train from Union Street to Union Square, I would have a seat on every R train over the same route for the duration of my trip. Realizing this, the analogy breaks down completely.
Fleming's main argument as to why Transit is like Circuits is that the bandwidth hierarchy, in traveling by train, then bus, then feet, is like the digital transmission hierarchy of telephone (i.e. circuit-switched) networks. Perhaps he lives and works directly on top of an interstate and has never driven by highway, then arterial, then local street in his car. Or never noticed that the bandwidth on his home broadband connection is orders of magnitude smaller than the trans-Atlantic fiber lines that connected me in London to his web server in Georgia.
In a circuit-switched network, I only use as much bandwidth as I need at that moment, and only on the single link I'm currently traversing. When I get to the end of that link, I am put in a queue until the next link on my path is ready to receive me. It's true that it's a bit more obvious to see a road/auto network as analogous to a packet-switched network, but only because of the apparent simplicity of the rules of the system. Transit networks are of the same nature, it's just that the way packets (i.e. people!) are queued and switched where links connect is more complicated and constrained than on roads.
Speaking in data-network terms that we are all familiar with, transit mops up auto when it comes to bandwidth (total bits, or people, per unit time). The problem with transit is, in some circumstances, higher end-to-end latency (the time it takes for the first bit, or person, to get where they're going). But once you get the flow started, we all know that one track of even light rail service can carry the same number of passengers per hour (or was it bits per second) as 7 lanes of freeway or 17 lanes of street (see here).
Unfortunately, people actually read and believe this kind of proof-by-bad-analogy thinking. In a recent newsletter from the Reason Foundation, Robert Poole, Reason's Director of Transportation Studies, claims to have had his "Aha!" moment when reading Fleming's piece. Too bad for him the "Aha!" wasn't a realization to be much more careful with his analogies.
This page contains an archive of all entries posted to Frumination in the transit category. They are listed from oldest to newest.
subway is the previous category.
transport is the next category.
Many more can be found on the main index page or by looking through the archives.
