Comments on: Downtown and the geometry of cities

By: hamilt0n

hamilt0n — Thu, 19 Apr 2012 15:56:00 +0000

“I think it’s also worth pointing out that the vast majority, if not all,
cities in capitalist countries have a wedding-cake style design. The
ones that don’t are largely cities built by communist dictatorships –
cities like Moscow, Beijing, and Pyongyang.”

This is really offensive. You should have included DC and Arlington in that list.

By: DYSPEPSIA GENERATION » Blog Archive » Downtown and the geometry of cities

Wed, 09 Mar 2011 03:34:32 +0000

[…] Read it. While mass transit technology has improved (though not nearly as much as it would have had we not regulated the private companies out of existence and replaced them with sclerotic publicly-managed shitholes), I doubt it will ever get to the point where extra density downtown is not the market equilibrium. Without access to lucrative jobs in Midtown and Lower Manhattan, would Scarsdale still be able to support all its local jobs? Without the R5 bringing people from Philadelphia’s Main Line into Center City, would all those local jobs still exist? Probably not. […]

By: Bill Nelson

Bill Nelson — Sun, 27 Feb 2011 22:24:00 +0000

As a city sprawls outwards, the average difficulty of going from one random point to another grows exponentially, while the difficulty of commuting directly to the center increases linearly. (I’m not the best at explaining mathematical concepts, so if someone could formalize this in the comments, it might help others understand.)

I think what you mean to say is that if an urban area spreads like a circle, than the area (= pi * r^2) will be the square of the radius. So, if you’re traveling randomly in that area, your trip will grow with the square of the radius. But if you are going to the center of the area, then your trip will be along the radius.

But these days, there are two sorts of “downtown” jobs. One is the “old” downtown, which is typically comprised of government workers, non-profits, and the like. This downtown is what used to be the main downtown, which the high-value “Midtown” jobs have long-deserted. In fact, it’s curious that you use Lower Manhattan as an example of a place with “lucrative jobs”. They’re lucrative if you count the DMV, the DOT, the MTA, and so forth, Otherwise, the financial firms have largely left; a walk down Wall Street will pass more residential conversions than anything else.

Try this: Go to Google Maps and a do search for “financial” in the Wall St zip code, 10004. Yes, you will see many results. Now zoom out a bit and scroll to Midtown, and you’ll see how tiny the downtown “financial” district is. A strong possibility for this is that the people in finance are pretty likely going to live in Westchester, New Jersey, and Long Island — for which Midtown is much more convenient.

New York is an exception, though. In other cities, these sort of businesses did not leave downtown for midtown; they entirely left the city itself. But they left for the same reasons that created the exodus in Manhattan.

That is: In almost every city, the new downtowns have shifted their locations (generally to the north and the west) and offer jobs that are not intended for people living everywhere. Instead (as in Chicago, Dallas, Atlanta, Detroit, Memphis, etc., etc., etc.) these new downtowns are quite convenient to their workers — who generally live nearby. Yes, the janitors have to sometimes have to travel a bit — but a good deal of the janitors’ neighbors (except for the civil servants) aren’t working in any downtown anyway. The construction workers, home health attendants, supermarket employees, etc. work where people live — so their “downtown commute” is not relevant.

Perhaps the “wedding cake” still exists, but it’s no longer in the geographic center — especially if you examine the density of high-value jobs as opposed to population densities. (And of course, in cities like Detroit and Cleveland, the “business district” is neither the center of population, high-value jobs, low-value-jobs, or even the geographic center.)

By: Rationalitate

Rationalitate — Sun, 27 Feb 2011 18:53:00 +0000

But it is at the center of its transportation network, which is what really matters here.

By: Marcin Tustin

Marcin Tustin — Sun, 27 Feb 2011 13:35:00 +0000

Counterpoint to a city with its CBD in the centre: New York. Manhattan isn’t remotely in the centre of the the city.

By: Leo Robin Shine

Leo Robin Shine — Sun, 27 Feb 2011 13:15:00 +0000

How can it be exponentially harder to go from one random point to another but only linearly harder to go to the centre?
If it’s only getting linearly harder to go to the centre then going to the centre then back out will also be linear?

By: Alon Levy

Alon Levy — Sun, 27 Feb 2011 05:16:00 +0000

For mainline rail, sure. For urban transit, not really. Tokyo Metro and the MTR are being successfully privatized, but Japanese subways other than Tokyo Metro and a few lines owned by the private railroads remain municipal; in Europe, the last attempt to privatize, in London, ended in disaster and the public sector had to take over again at a loss.

(On another note, privatization means two separate things in Europe and most of Asia. In Europe, rail privatization means open access. In Japan, it means going back to the private systems used in pre-Amtrak America – i.e. the tracks are privatized and companies run trains on their own tracks, with through-service to other companies’ tracks baesd on bilateral trackage rights agreements. In Asia ex-Japan, mainline rail is public, but subways can be private or public; if a subway is operated by multiple operators, like in Singapore or Shanghai, transferring from one company to another will be seamless, unlike in Japan.)

By: Rhywun

Rhywun — Sun, 27 Feb 2011 03:52:00 +0000

The trend now almost everywhere except the US is privatization, at least of the operation of the vehicles. The main benefit is to lower the cost of such operations by removing the power that public-sector unions have amassed for themselves over the years, which has resulted in grossly outsized salaries and benefits in comparison to the private sector – costs which are simply not sustainable in the long run as we are beginning to see here in America as cities and states across the country are slowly admitting how broke they are.