Urban traffic engineering

James’ post about the Oxford Circus redesign fails to distinguish three very different ideas about managing movement in urban spaces, though if you follow his links you can parse it out.

The culture of traffic engineering is about moving cars (in parts of Europe, bicycles and trams also) quickly, and one of its tropes – James’ main target – is to get the damn pedestrians out of the way. Also the bicycles, in most of the US until quite recently: the Secretary of Transportation of Massachusetts said to me in 1981, when I asked what programs he was planning for bicycle commuting, “well, they mostly just interfere with traffic, right?”.   This leads to fences along curbs to prevent jaywalking and funnel pedestrians to approved crossing lanes, and some really appalling things like the two-story stair climb required to cross the eje’s (arterial through streets) on which Mexico City drivers drive park in ranks and files during rush hours, not to mention the quarter-mile hike along the eje to get to one.

The first big idea is the realization that cities are not about being easy to drive cars through; cities are about being easy to get about in by many modes, especially including feet (and wheelchairs), and having places that are nice to dawdle in.  Respect for modes other than cars has led to some quite amazing engineering, like the four completely separated  interlocking, light-controlled systems for pedestrians, bikes, cars and trams in the Netherlands.

The second idea is a fairly modest innovation, called the Barnes Dance when introduced in New York by Henry Barnes, the traffic commissioner: this is the four-way red for cars at orthogonal intersections and free pedestrian movement between any two corners.  It turned out to slow vehicle traffic very little and greatly eased walking; this is the idea introduced at Oxford Circus, where allowing people to walk in the direction they want to go allowed the removal of a bunch of fences and street junk.

The third idea is genuinely revolutionary.  Hans Monderman, one of my heroes, was the  champion of the astonishing idea that a lot of busy, complicated urban spaces work better for everyone if cleared of traffic lights, sidewalks, curbs, and crossing controls and turned into a free-for all (I also have to admire the courage of the elected officials who let him try this the first time).  It turns out that when they aren’t dependent on lights and lanes, and know that the right-of-way is full of pedestrians, bikes, and hot-dog wagons, drivers slow down, take care, and (this is one remarkable outcome) get through the space faster. Pedestrians step out of the way of the cars with modest inconvenience, and (this is the other remarkable outcome) accidents, including pedestrian accidents fall substantially. Obviously, there is an inescapable tradeoff between pedestrian and car convenience, and between safety and convenience, but these are two more of the many obvious things that are also false.

The recognition that behavior is not always improved by formal controls, but often by transferring decisionmaking back to people who can efficiently size up situations and will generally be polite and cautious, is quite important and much bigger than street  design.  In my business, to mention only one example, a lot of my colleagues seem engaged in a losing arms race with their students to control cheating by what seem to me to be infantilizing rules, requiring them to put their backpacks on the floor at the front of the room during exams, not letting them come back in the room if they go to the bathroom, and the like.  That kind of thing really grates on me; I don’t see how I can expect students to act like grownups if I treat them like children, much less juvenile delinquents.  It’s possible I’m being cheated blind, but I’m pretty sure I do better giving only open-book, open-notes midterms (this helps them not obsessively memorize stuff) that are all  essay questions (for which I tell them, stuff they bring along probably won’t be useful but might be comforting), but nothing electronic allowed.   They also grade each other on class participation, so I can expect a certain amount of peer control for which I don’t have to play Mommy; presumably most students will be inhibited about being seen to cheat by exactly the people they are cutting in line ahead of, and who will be registering consequential judgments about them.

Positive Train Control

Metro testing suggests that a single-point failure in the block control system caused Monday’s fatal crash. This is an unacceptable design and Metro should shift to a positive location model with the block control system as back-up.

It seems that Monday’s fatal metro train crash in Washington DC was caused by a failure of a block control signal that should have indicated the presence of a train in a block of track. It is incredible to me that in the 21st century that such a single failure point could result in a crash. Apparently Metro has two other train location information systems but neither has direct authority over the trains.

In other words, so far as positive train control is concerned, trains can just disappear from the system if a block sensor is defective. Instead, Metro should have a system that maintains continuous knowledge of where a train could be based on the totality of information from various sensors (including GPS when trains are in the open and other positive location techniques when trains are in tunnels), and this picture should be extended by physics to provide a range of uncertainty about where trains could be based on the information in the system. The block control information should serve as a back-up to this positive control picture, stopping trains as necessary but only once the primary system has failed to provide adequate control.

All trains that could possibly overlap in space should come to a stop when the block control information diverges from the positive control model. The block control information and the identified train location information should be continually checked against each other, triggering train stoppages and immediate repair to resolve any discrepancy.

Disclaimer: I am not a transit engineer and am relying solely on information published in the Washington Post.


This is written as the Dow is sinking almost 7% through about 9600, after a similar day on foreign markets. The judgment of investors isn’t the rousing endorsement of the bailout some had hoped for. And Floyd Norris passes on the following CNN poll result:

As you may know, the U.S. went through a depression in the 1930s in which roughly one out of four workers were unemployed, banks failed across the country, and millions of ordinary Americans were temporarily homeless or unable to feed their families. Do you think it is very likely, somewhat likely, not very likely, or not likely at all that another depression like that could occur in the U.S.?

Very likely, 21%

Somewhat likely, 38%

Not very likely, 29%

Not likely at all, 13%

Hmm. The 59% in the first two categories, think they’re headed for the mall and the car dealer and the Sunday open houses?

Time for some old-fashioned 1930’s stimulus: every day of unemployment by every willing worker is a day’s value creation lost forever. Forever. Not to mention underemployment. The good news in this state of affairs is that it’s occurring at a time when investment in the kind of thing government is good at buying, especially infrastructure, is just the ticket. It will never be cheaper to buy houses for transit right-of-way, and the construction workers not building tract houses and office buildings will never be more grateful for jobs.

This piece of good fortune is aligned, with more luck than we deserve, with a whole expensive shopping list of stuff we need to do to slow, and adapt to, global warming. This shopping list is a fantastic Sunday supplement insert of bargains, things that are such a great deal we should happily go into hock for them (unlike a house with two bedrooms for every occupant and a three-car garage). We need transmission lines to get electricity from where the wind blows to where people live. We need high-speed rail to connect the downtowns people are moving back to. We need nuclear power plants. We need a lot of expensive research on stuff like vehicle batteries, geoengineering, and carbon capture and storage. We need a lot of cheap research on how to teach people that driving a big car is just rude.

Of course, with credit locked down and the private sector on a gurney with a drip, these are only possible if government steps in. If that happened, it would mean that the smug philosophers of “small government and low taxes forever and no matter what” would have been wrong. If it happens in an Obama administration, it would probably mean that the opportunities for no-bid cost-plus ripoffs by friends of imbecile appointees would be greatly constrained. Perhaps these are good reasons to hunker down and have the depression; a slogan is a terrible thing to throw away just to save an economy, and anyway the people who matter have already socked away enough to be set for life.

In fact, a lot of nice things will be cheaper with breadlines keeping the labor force docile…now that I think of it, a carpenter building a school is one less waiter bringing a drink to poolside.

Why Everyone is Wrong About the New LA Fast-Food Ordinance

Lots of chatter over the last few days in the blogosphere about Los Angeles’ new ordinance banning new fast-food restaurants in south LA. (Not “South Central”: we don’t call it that anymore). And everyone is wrong.

My friend and colleague Steve Bainbridge, whose picture is in many dictionaries next to the word “curmudgeon“, sees it as not-so-creeping nanny state-ism. So does Will Saletan.

Matt Yglesias and Ezra Klein have gaskets of their own to blow: arguing, where have you guys been all these years? That’s what land use regulations do. That is true but I think somewhat overstated: there is a difference between a land use regulation purportedly designed to block externalities, and a land use regulations purportedly designed to help those who won’t help themselves. That’s more paternalistic, and many might find it wrong.

But here’s why they are all wrong.

There is a more moderate way to protect public health: full disclosure of the health harms of certain kinds of food. One might argue that people still won’t protect themselves, but before getting there, and engaging in the philosophical question of whether it is then okay to intervene, it makes much more sense to try truth-in-labeling first.

Why isn’t Los Angeles doing that? There’s a pretty straightforward explanation: they might very well get sued and lose if they do, because food labeling might be pre-empted by state and federal law. So they use their land use authority, which isn’t pre-empted, even though it is a more blunt and problematic instrument. This happens a lot: cities can’t tell certain kinds of stores to unionize, so they just make sure that they don’t get permits until they do. Then businesses complain about the difficulty of getting permits.

Progressives are gradually waking up to the real potential of local governments in advancing the progressive agenda. But in the fast-food case, it’s one that many conservatives might endorse as well, because it is less paternalistic. Restaurants, of course, will sue to stop the new regulations, but that’s why cities are jumping on the bandwagon of the LA ordinance. They are telling the fast-food places: okay, fight us in court on this, but don’t be surprised if in the future you can’t get a permit at all. (And the existing stores will be amortized out of existence in a few years). That’s the way the game gets played. And in any event, that’s no reason for the rest of us to try to get better legislation at the state and federal levels to allow localities to regulate their own communities (assuming that they can’t now, which is still an open question.).

Steve says that fuller disclosure is silly, too, since “if markets demanded that sort of behavior, we would observe it. We don’t.” I think he was in a bad mood: even libertarians (which Steve is not) might concede that you can’t really have a market demand if the information isn’t there. Moreover, if you are someone in south LA, and you want more market information, it is very difficult to take your business to more transparent restaurants if there aren’t any–not to mention the transaction costs of getting lots of other folks to do the same.

All of that said, however, there is one other overwhelming reason why the charge of nanny-state-ism doesn’t work very well here: children. Fast-food places market to children. They make themselves attractive to children, including playgrounds, marketing with popular movies etc. Particularly as children get just a little older but still under 18, they have some disposable income. But it’s perfectly legitimate to be paternalistic toward children. As for the younger kids, as the father of a four-year-old, I can tell you that lots of us wouldn’t necessarily regard it as paternalistic for the government to help us out and take away some of the many opportunities for fast-food restaurants to give our children an excuse for a crying fit.

One last thing: there is one possible externality here. To the extent that low-income people eat more fast food, that also means that they will be placing a greater burden on the public health system and making big insurance pools riskier. So on that basis, I suppose you could say that this isn’t nany-state-ism at all, it’s protecting the public fisc (and what we hope will be the public fisc.). I’m not sure that this works because it might prove too much. John Edwards’ health plan wanted to require people to have health exams as part of it, I imagine mostly for fiscal reasons. But many people saw it as too intrusive. You can’t just slap the label of “externality” on something. This is a broader issue, probably for other posts (and other writings).

End of Land Use 101.

Highways of metallic isolation

L.A. would be great if not for the billboards. That, and teenagers driving Hummers. Oh, tourists, also.

Los Angeles is blessed with a stupendous natural environment, and a somewhat-less-so built environment. I don’t have a ready solution to the blight of Tuscan-style corner malls, but when I am named Grand Vizier of Westwoodistan my first edict will be to abolish billboards* (I’m sorry—”outdoor advertising”).



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The homeowner and the fire

The homeowner whose house four firefighters died protecting in the Esperanza fire has a profile in the LAT today. It’s a second home, in which he invested years of work and where he stored a collection of Indian artifacts and antique cars even though, in his words, “there are quite a few fires up there”, one of which was stopped only 800 feet from the house.

What’s really wrong with Wal-Mart

I have to weigh in to the Wal-Mart discussion, because if we only talk about the retail and labor economics of this institution, we are missing something that may be even more important. I’m thinking about the degradation of everyday life Wal-Mart, and all big-box stores and malls, enforce as an inseparable condition of their ability to provide a lot of stuff at a low cash-register price. I use that awkward phrase to emphasize that things we pay less money for may still be expensive in other ways: getting stuff at places like Wal-Mart is a transaction in which we sell our humanity for money. The reasons are a little complicated, and have more to do with automobiles than employment practices; bear with me.

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