A long, green Big Apple

I was not browsing the Christian Science Monitor the other day.  I did not find the following article on it:

http://features.csmonitor.com/books/2009/09/16/green-metropolis/

(Ok, ok.  I was, I did, and then I lied about it. I’m sorry.  Hush now.)

It’s an article about how New York City is environmentally friendly.

‘But it’s covered in concrete!’ The article is about how a tightly packed, dense city can change people’s behaviour. You spend less time buying exotic flatpack furniture and own less cars if you have a tiny studio apartment.

The constraints of the city mitigate residents’ environmental impact. While many environmental effects (litter, pollution, concrete) are visible in NYC because of their concentration, they are probably lower on a per capita basis compared to, say, Greater DC.

One Christian Scientist commenter said he was moving out of NYC to start a family.

It is commonly said that the best thing to do for the environment is to refrain from reproducing. I wonder how many New Yorkers have actually limited not only their consumption but also their families to a size accommodated by their petite apartments?!

Why?

I have thought a lot about how New York survives and thrives.  What makes an efficient city? Density, no doubt, but also shape.  A long thin city won’t minimse the distance to the center, but it efficiently arranges the transport system.

Once your city is too big to walk round, distance is not so important as an efficient transport system.

Think about a small country town, arranged along a single road.  Or  a city office block, which has a central block of elevators.  In the same way, a city with a single central arterial will be efficient. You can run a really good road and a really good tram, train or bus up it.

I think Manhattan’s density is made bearable by the fact that it is north-to-south long and east-to-west skinny.

This means you can have well built transport corridors running along its length. In a long city, riding the subway requires less interchanging than a grid city. And in the road network, the lengthways roads are more important than the crossways roads, meaning that the most important roads needn’t cross.

Intersections are inefficient. I reckon there’s game theory in this.

Imagine a city has a centre. I want to live as close to it as I can. If I have to live off the main road and merge on to it, there’s a time cost for me there that I will take into account. But there’s also a time cost for the people I merge with. I’m not going to take that into account. By putting a city on a long thin piece of land, it curbs the extent to which I can impose costs on others.  (‘Bridge and tunnel people’ obviously don’t fit into the theory too well.  Maybe that’s why they’re unpopular in Manhattan…).

A linear roadway is good, but would end up being big, heavily trafficked and not too nice for pedestrians.  The cool thing about a linear subway would be if it could coexist with a tangled, walkable, dynamic surface level, by snaking back and forth under the surface.   I reckon New York has a bit of both.

Thoughts?