Comments on: When Santa Monica Takes Traffic Surveys, They Slow Streets Down

By: ubrayj02

ubrayj02 — Thu, 20 Aug 2009 18:08:21 +0000

There are many reasons for this mandate from God: cheap and abundant domestic oil in the early 20th century; the intention of spurring on consumerism (auto based areas spend a lot of cash); and generally just greed by land speculators and auto industry titans.

I read through the Institute for Transportation Engineers self published history to understand where these folks come from with this car-centric bias to road design. It was quite informative:

http://www.ite.org/aboutite/History.asp

“The Early Years: Establishing an Identity” describes how this trade group has really built itself around making roads for cars. They are, I think, intentionally misleading us by calling themselves “transportation engineers”. Motoring psychologists would be a better term – since the medium they engineer is humans in motor cars.

We would be well served to complement our “engineers” with a smattering of sociologists and anthropologists who can measure the direct impact (safety, community livability, quality of life, economic sustainability) much more efficiently and effectively.

By: angle

angle — Wed, 19 Aug 2009 22:26:15 +0000

So the LADOT staff designs ever bigger and faster roads, planning for a future that has a growing population using more and more private automobiles. I think most people would say that this is a natural state of expansion, an unavoidable, self-evident condition of progress. What I wonder is… where does this mandate actually originate from?

By: ubrayj02

ubrayj02 — Wed, 19 Aug 2009 18:39:03 +0000

angle,

Who is deciding the speed limits we have?

In LA it is the proviso of the LADOT’s operations staff. They design roads for higher than posted speeds and jump at the chance to increase speed limits when they do their surveys.

By: Reply to Winston

Reply to Winston — Wed, 19 Aug 2009 18:04:24 +0000

Winston, you got it right. Studying traffic engineering and driving on both narrow and wide streets have taught me many things. One, if the street is wide, you’re more likely to drive fast. If the street is narrow, you’re very likely to slow down. I live in Valley Glen, in a neighborhood with streets of various widths. My neighborhood council is advocating for a street widening to accommodate just 80 vehicle trips from an infill apartment housing project. That project’s curb cut is on a narrow street that isn’t quite classified as a one-way so people have to show courtesy and yield. The point is, people are freaking out over traffic and noise. I pointed out that widening the street will make the fire chief happy and make it more appealing for people from that new building to drive, and drive faster. By keeping the street at its current width, cars will have to travel more slowly, which will also generate less noise, fewer fumes, and allow us to maintain the intimacy of that street.

But the talk of a traffic engineer/urban planner probably didn’t sit with them very well.

By: angle

angle — Wed, 19 Aug 2009 02:18:58 +0000

“It is a much better idea to modify a street to encourage the kind of traffic flow you want than it is to post an artificially low speed limit and create dangerous differences in speed.”

So who is deciding what kind of traffic flow we want?

By: NoHo Mom

NoHo Mom — Tue, 18 Aug 2009 22:20:05 +0000

There is a huge speeding problem in the valley. That compounded with the red light running issue is making the streets very unsafe for pedestrian and bicycle traffic.

By: jay

jay — Tue, 18 Aug 2009 20:04:48 +0000

The problem is light timing. If, for example, you are driving down Wilshire, the lights should be timed such that if you drive the speed limit, you almost never have to stop at a light, but if you drive faster you do. If that were combined with people actually following the “left lane is only for passing and turning” convention, traffic would flow much more easily.

By: Winston

Winston — Tue, 18 Aug 2009 18:33:24 +0000

The California law that mandates that speed be set at the nearest 5 MPH increment to the 85th percentile speed (with a couple of exceptions) is a very good law because it turns out that the speed limit doesn’t affect how fast people drive very much but the design of the road does. It is a much better idea to modify a street to encourage the kind of traffic flow you want than it is to post an artificially low speed limit and create dangerous differences in speed.

Remember the problem isn’t the speed limit, it’s the design of the road.