Thursday, November 20, 2008

Newton Centre Traffic Study

Missed last night's Public Safety & Transportation meeting last night. Among other things, missed the presentation of Traffic Solution's study of Newton Centre.

Lots to digest, but loving the roundabout proposals!


Denis said...

Those two proposed roundabouts sure would be game changers. A constant flow versus stop and go would be nice. I'm doubtful about cars actually stopping for pedestrians, especially at peak times.

Adam said...

Hey, I'm a big roundabout fan, but I'm a bit skeptical about how it would work in such a high traffic situation, especially with two lanes. Also, pedestrian crossings just outside the roundabout scare me. If people actually have the mental capacity to see pedestrians and stop for them after going through the roundabout, wouldn't that likely back up the traffic into the roundabout and cause it to fail?

The stop on Cypress would likely cause huge backups on Parker Street and make it extremely difficult for cars coming from Newton Center to Cypress which no longer have the right of way. It's hard to see the right of way changing without adding signals to that intersection.

Steve Runge said...

I'd be interested in seeing some research that would support mixing rotaries with high pedestrian traffic. My experience as a driver and pedestrian & intuition combine to say "Very Bad Idea."

The generic "and add a bike lane" in each section was a little irritating, as well. No specifications about where or how. Just, "Oh, right, and we're supposed to recommend bike lanes."

It seems as if their lower-impact recommendations (signal timings, etc.) would clear up most of the traffic problems on the cheap.

Does anyone have an insight into the rhetorical strategy of recommending rotaries? Do you not get this kind of work without recommending some kind of major engineering boondoggle?

Steve Runge said...

Hi, again.

A Dutch study of rotaries finds that rotaries with a tight diameter and 90-degree entrances/exits slow traffic enough (20 mph) to make for safe pedestrian crossings.

Incidentally, the study pointed to FHWA & Dutch data that says lowering traffic speed from 30 to 20mph reduces the likelihood of death in a car-pedestrian collision from 45 percent to 15 percent. So that 20mph threshold is pretty damn important. I can't really tell if these rotaries achieve that.