Thursday, May 27, 2010

Traffic irony

If you believe, as many do, that well-planned, well-conceived density around transit nodes -- like Newton Centre -- will reduce overall car use, then savor the irony that a large obstacle to more development in Newton Centre and thus reducing traffic is ... traffic impact.

That it is ironic doesn't mean that traffic impact isn't a valid concern or that those worried about it are wrong to worry. It's just ironic.


Anonymous said...

That's true about pretty much any development near where people already live, and explains why it has been so much easier for developers to build on the urban fringes... no NIMBYs.

dr2chase said...

We have pretty much the same problem in Belmont.

I don't think that "the worried" are necessarily wrong to worry (it makes sense to think that adding people is likely to add at least some cars, and adding cars increases traffic, right), but consider the other rule that we have learned empirically; if you add capacity, you get more traffic. (See, for example, Houston.)

People looking to get from point A to point B will take the new, larger road, as long as it is less clogged than the alternatives. If a large fraction of your traffic is cut-through, I think a reverse corollary ought to hold -- if you add more local traffic, it will displace cut-through traffic onto other less-clogged roads. You will still get a net traffic increase, but it ought to be a smaller increase than simple car arithmetic would predict.

The other thing to do, is try to shape the traffic so it is ped and bicycle friendly, so that good alternatives exist, at least for people with a local destination.

Note, in particular, that Cambridge is dense and developed, and they cheerfully muck up traffic with all sorts of one-way streets and no-turn intersections, and provide grossly insufficient parking. As a result, if I am traveling to Cambridge, whenever possible I ride my bike (which, as it turns out, is just as fast as the T, and within a few minutes of car time, with no risk of traffic jam delay, and no parking problems).

dr2chase said...

PS - the goal is to achieve Yogi Berra density: "Nobody goes there anymore, it's too crowded."