The Gates public art exhibition in February 2005 closed the Loop Drive of Central Park to automobiles and attracted millions of visitors to Central Park (and spawned at least one other public art idea pictured above). But it did not cause the kind of traffic calamity that Starquest expects a Loop Drive closure would.

Starquest, better known as Henry J. Stern, is a thoughtful person who not only wishes the best for the city, but has dedicated enormous amounts of energy in his former job as the New York City Parks Commissioner and more recently as an urban philosopher to improving the city's built environment. Having seen him deftly moderate a contentious public panel on the possibility of reopening a waste transfer station on the Upper East Side, I have grown to respect his abilities to navigate the city's political landscape and I enjoy reading his columns, which he kindly e-mails out to me (and anyone else who signs up to receive them).

He recently wrote a surprising column on the idea of banning cars from Central Park that appeared in the New York Sun and shows a misunderstanding of the results of a full closure of the Loop Drive (which would go beyond the partial closure announced last month). He wrote: Although banning automobile traffic in Central Park would be pleasant from a park point of view, it would be disastrous for neighborhoods on both the East and West Sides of Manhattan. The cars prohibited from using the park at rush hour would not simply disappear; their drivers would use alternate routes, going south on Columbus and Fifth Avenues, north on Amsterdam and Madison Avenues, and both ways on Central Park West and Park Avenues.As a former Parks Commissioner, one might hope that Mr. Stern would take the "park point of view," and let the Transportation Commissioner worry about the traffic impacts outside of the park. A parks commissioner should perhaps be advocating for better parks. But he's no longer in that role, so this isn't the main point of my criticism of Mr. Stern's opinion.

His view that rush hour traffic "would not simply disappear," for which he provides no supporting documents, is a hypothesis contrary to history. The more surface area of the planet that you devote to the movement and storage of automobiles, the more traffic you have. Adding lanes upon lanes to Los Angeles freeways has not helped that city avoid traffic congestion. It has encouraged a built environment that requires the car for all trips, thus boosting traffic congestion there. In L.A. and elsewhere, when you build lanes, cars will fill them. People are induced to drive by through public investment. This is called the "induced traffic effect." Central Park's use as a major traffic artery encourages people who would otherwise take the subway to drive instead.

The converse is also true. When you reduce the roadway space given over to automobiles, you discourage driving, causing traffic to disappear by squeezing it out of existence. We're not talking about Los Angeles here. This is New York City, where people evaluate each trip they take before they take it and select a mode according to a host of factors. Of course, closing the Loop Drive would eliminate a great deal of the north-south traffic at 59th Street's intersections with Sixth and Seventh Avenues. (Ditto for 110th Street's intersections with Lenox and A.C. Powell.) The benefits of this would radiate north and south from the park for many blocks.

But beyond these localized benefits, closing the loop drives would cause a percentage of the people who formerly would have driven to take the subway instead. Nobody is talking about closing the depressed east-west transverse roads. The loop drive is a north-south route that is parallel to no fewer than 10 subway lines, namely the A, B, C, D, 1, 2, 3, 4, 5 and 6. The air quality benefits of this modal shift are enough to make this a valid public policy decision, regardless of the improvement "from a park point of view," reduced asthma cases, better social interaction of the people who will come out of their metal-and-glass shells, fewer traffic deaths and injuries, a lowered demand for parking spaces south of 59th Street and increased revenue for the MTA.

The Gates went off without a traffic nightmare, and a regular closing of the loop drive will not either. History is filled with dire predictions of traffic nightmares that would result from street closures but that have failed to materialize. Why not test it out with a trial closure and see what happens?

- Horseless Carriages [NY Civic]
- Disappearing Traffic? The Story So Far []
- 'The Buckets' [S&F]
- Partial Car-Free Trial in Central Park [S&F]