Tuesday, January 24, 2023

A Caution on Roundabouts, Avoiding Culture War on Vision Zero - Bits

There's been a flurry of posting and enthusiasm for roundabouts on social media, and they were even mentioned a little last night at Council in the conversation about Vision Zero.

Getting on 20 years ago now, Springfield installed what might be the first modern roundabout in Oregon. It is terrible! More contemporary designs avoid some of the problems with it, but it is worth looking at as a caution. 

Roundabouts fundamentally are designed for car flow. One slide in the social media posts even highlighted "no stop." 

Roundabouts offer convenience and improved safety for those inside of cars, but they still too often make insufficient provision for the walking and rolling public. They also do not fit very well into a genuinely urban fabric.

An early roundabout in Springfield, c.2006

The one in Springfield:

  • Uses a huge amount of space. Space in the center is unused. Space on the rounded corners have very large setbacks with landscaping. It's in a mode of very suburban land use.
  • Slip lanes lengthen the crosswalks and make for chunks of out of direction travel in multi-phase crossings. Pedestrian travel is inconvenienced.
  • Bike lanes just simply disappear, and to continue a person on bike has to use the sidewalks.
Bike lane ends on the approach to the roundabout

People arguing for roundabouts are often - not always, but often - still arguing from a fundamentally autoist perspective: The roundabouts keep car travel flowing, get pesky people on foot and on bike out of the way, and make the driving more convenient. Consider the way they are featured in the OR-22/OR-51 proposals from ODOT, as well as the one for 99W and Clow Corner Road near Independence. Even the lauded roundabouts in Bend force people on bike up onto the sidewalk and into crosswalks, for a real deflection from straight-line travel.

ODOT's formal assessment found more speeding

Not all roundabouts are bad, but they are not quite the panacea people might want them to be. They require careful deployment and design in order to meet the needs of all users, not just those in cars.

A Unifying Case Study?

December 2020

Last night at Council in the conversation about Vision Zero, Councilor Gwyn mentioned the loss of Selma Pierce, whom a driver had struck and killed when she was out for a walk a couple of years ago.

As a way to bridge non-partisan and bipartisan conversation, and a way to side-step or even persuade people who might like to make Vision Zero a contested site in our ongoing culture wars, Council and the City could consider talking about how a more thorough Vision Zero approach might have saved the life of Selma Pierce. In some conversations, not necessarily all of them, centering her loss might be helpfully advance understanding and support.

Claims for a Vision Zero Success

via Twitter

Finally, it has seemed like Vision Zero was very often more talk than walk, a definite kind of performative signalling over substance.

A CityLab story from last month, "How Jersey City Got to Zero Traffic Deaths on Its Streets," identifies a partial success.

There's not enough of a track record there to say how persistent this one year of zero fatalities will be. It could just be random variation and not quite durable. But it does count as a partial success.

And in the piece are tips and hints that could strengthen Salem's effort. Even if it's not an unambiguous road map, it's a resource.


Salem Breakfast on Bikes said...

[Moderation note: Don posted this as a comment on a different post, and I am certain he meant for it here.]

An increase in mean speed is not necessarily an increase in speeding.

If the junction they had was frequently overloaded and thus cycles of lights would go through without movements of cars, the better flow of traffic would be seen as an increase in mean speed.

Multi lane roundabouts do have more challenges then standard or "mini" single lane roundabouts, but often single lane roundabouts slow drivers down enough to make bike travel much safer, as well as the increased complexity making pedestrian and bikes safer as drivers have to pay attention to traffic flow.

Center areas of round about also provide green space and permeability to otherwise solid asphalt and concrete roadways, particularly in downtown areas where permeability can be difficult to come by.

Are roundabout a placenta? No. There are times where platooning cars can be more effective, or controlled access highways ect.

Walker said...

I’m so glad that roundabouts aren’t a placenta, that would be gory and smelly after a while.
They aren’t a panacea either.