July 28


Shared Space Roads – A Primer

By Mike Spack

July 28, 2011

Shared Space Road

Sharedspace1 The "Shared Space" road is a throw back concept in which pedestrians, bicyclists and vehicles are equals in using a road space.  There are a few proposals for Shared Space roads being brought up in the U.S.  (Shared Space immediately makes me think of the 19th/20th turn of the century photos of New York City.  I don't think proponents of Shared Space want to invoke that image though.)

By removing curbs and traffic signs, we expect motorists to be more cautious because the environment isn't giving them the impression that they're superior.  At least that's what Hans Monderman found with his experiments in Europe.

As I have written many times before, I am a minimalist when it comes to signs and other traffic control devices.  Only install them where they're needed.  So I somewhat agree with the Shared Space (or living street as others have called it).

The key with Shared Space is to keep the number of vehicles on it low (as my mentor Shelly Johnson taught me – all traffic designs work great as long as there aren't any cars, but your design better be very good if you have heavy traffic).  Here's my checklist if I was brought a Shared Space road to review:

  • Designed so vehicles would have a very difficult time going over 20 mph.
  • Need fantastic gateways into the street segment letting motorists know they are entering a different kind of road.
  • I don't think I'd want transit on it because designing for LRT or buses would open up the road and make it easier for cars to go over 20 mph.
  • Heavy landscaping and sight lines designed for the 20 mph speed (or 15 mph).  No over-engineering.
  • Better be an area that will have a lot of pedestrians.  Otherwise, don't bother.
  • No curbs.
  • No signs.

I'd be open to a Shared Space road in my neighborhood, but it definitely shouldn't be on an arterial street.  The concept should start on neighborhood roads or in commercials zones that are a destination.  Don't bring the concept of Shared Space to the U.S. on roads that are meant to move motorists regionally.  And vehicle speeds MUST be kept low on them so they don't become a safety problem.  The traffic engineer would have to throw out their expectation of limiting the amount of delay motorists experience.

  • Many communities already have what they consider to be shared space roadways. I once made a recommendation to a suburban community that wanted to improve walking conditions that they should construct sidewalks along all their local streets. They balked at the idea, and said that residents always walked in the streets just fine. Of course, there was nothing special about the roadways that made them any different than any other residential roadways, and they weren’t particularly interested in doing any substantial traffic calming either…

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    Mike Spack

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