Do Game-Theory-Playing Traffic Lights Reduce Congestion?

That is what the headline of this fascinating article says. Here is a quote from the news report:

In lay language," [Samah] El-Tantawy said in a U of T news release, "the [traffic lights] act as a team of players cooperating to win a game — much like players in a soccer match, where each player endeavors to score, but at the same time considers the ultimate goal of the entire team which is winning the match.

According to the article, travel times were reduced by 26 percent, which is fantastic, and which is what matters.

This doesn’t, however, seem to have much to do with game theory. Game theory is about one of two things: strategic behavior or finding sustainable equilbria. But the traffic lights don’t care about their own private utility.  There is no sense in which they are actors at all, as traffic lights just do what you tell them to do.  In economic terms, there is a central planner who sets the rules which the traffic lights obey. This new scheme provides a new and better set of rules (which, again, I emphasize is great), but I don’t think game theory should get the credit!

(Related: see our "Jane Austen, Game Theorist" podcast.)

Why My Favorite American Cities Have a Chinatown

Relatives from South Africa were visiting and we got to talking about which cities to visit in America. I shared my list: San Francisco, New York, Boston, Washington, DC, Seattle, and Philadelphia. Each city has a Chinatown. Coincidence? Or maybe the connection is just that I like Chinese food. Indeed, our family has been going to a favorite dim-sum restaurant most every week since moving to Boston seven years ago.

Then the larger connection came to me. Chinatowns were made by Chinese laborers building the railroads (when the laborers had finished this vast public-works program, the Chinese Exclusion Act barred most Chinese from emigration to or citizenship of the United States). Having a Chinatown marks a city as of the railroad era, built up before the wide deployment of the automobile. As Lewis Mumford said, "The right to have access to every building in the city by private motorcar in an age when everyone possesses such a vehicle is actually the right to destroy the city." Cities with Chinatowns had enough roots to escape carmageddon.

The Cities of America's Future

Writing in Foreign Policy, James Manyika, Jaana Remes, and Javier Orellana of the McKinsey Global Institute argue that cities in general and particularly smaller cities will power the new U.S. economy:

It is America's large cities, and particularly the broad swath of middleweights, that will be the key to the U.S. recovery and a key contributor to global growth in the next 15 years. Large cities in the United States will contribute more to global growth than the large cities of all other developed countries combined. We expect the collective GDP of these large U.S. cities to rise by almost $5.7 trillion -- generating more than 10 percent of global GDP growth -- by 2025.

The Controversial Legacy of Slum Clearance

A new study by Vanderbilt economist William J. Collins and Ph.D. candidate Katharine L. Shester looks at the long-term economic impact of the ambitious (and highly controversial) Housing Act of 1949, which used federal subsidies and the powers of eminent domain to "revitalize" American cities, i.e., to clear out the slums. By the time the program ended in 1974, 2,100 distinct urban renewal projects had been completed using grants that totaled about $53 billion (in 2009 dollars).

In one of the rare papers to collect and analyze data related to the program, Collins and Shester come up with a positive picture of its effects - at least in some ways. The authors are clear that the ugliness involved with pushing people out of low-income housing was the reason the program was shut down, and that their results do not “imply that the dislocation costs for displaced residents and businesses were unimportant.” From the abstract:

We use an instrumental variable strategy to estimate the program’s effects on city-level measures of median income, property values, employment and poverty rates, and population. The estimates are generally positive and economically significant, and they are not driven by differential changes in cities’ demographic composition.

Does Destroying Highways Solve Urban Traffic Congestion?

Strange how the traditional laws of supply and demand go out the window when it comes to traffic. Studies over the last decade (like this one, this one, and this one; plus the book Suburban Nation) have pretty much dismantled the theory that more roads equal less traffic congestion. It turns out that the opposite is often true: building more and wider highways can increase traffic congestion. If only people like Robert Moses and Le Corbusier had known this before their grand urban plans left our cities clogged with traffic, and carved up by ugly, value-destroying highways.

Urban Planning, Animal Style

Southern Sudan recently unveiled plans to remake its ten state capitals, with an interesting twist: "The $10.1 billion plan proposes remaking cities in Sudan's south into shapes found on regional flags. Blueprints and maps illustrate Juba in the shape of a rhinoceros, Yambio fashioned after a pineapple and Wau as a giraffe."

The Antiplanner

Few figures polarize the planning profession like Randal O'Toole, a senior fellow at the libertarian Cato Institute. As far as I know, O'Toole has never attempted to steal Christmas and was nowhere near the grassy knoll, but nevertheless if you're going to bring up his name at a gathering of transportation planners you'd better have a defibrillator handy. In part, the outrage O'Toole provokes is due to his sometimes colorful mode of self-expression, but basically it comes from the fact that he is one of a handful of planners (or, as he calls them, "antiplanners") who take issue with the prevailing orthodoxy in the field.

Who Joins Zoning Boards?

People with something to gain.

Step Up With Your Best Urban-Transportation Ideas

Nimble Cities at Slate.

A Shining City on a Spreadsheet

A spreadsheet models all New York City transit.