Autumn on Lake Audobon

Autumn on Lake Audobon
Autumn on Lake Audubon, Photo by Alison Kamat

Monday, December 27, 2010

Gridded Streets, Fred Costello, November 15, 2010

Reston Task Force member and engineer Fred Costello tackles the mantra by TOD proponents that gridded streets in TOD areas improve traffic flow.  He finds otherwise:

The conclusion is that, except in unusual circumstances of small block sizes and a short distance from origin to destination, a grid of streets cannot be justified on the basis of traffic flow.  The disadvantages of a grid of streets, as compared to a grid of walkways (between buildings), are the greater space between buildings and the greater hazard to the pedestrians.  Greater distances between buildings result in less efficient land use and longer walking distances
For the details of his analysis, read the two-page analysis below.
Gridded Streets, Fred Costello, November 2010                                                                   

1 comment:

  1. "except in unusual circumstances of small block sizes and a short distance from origin to destination, a grid of streets cannot be justified on the basis of traffic flow"

    I think you need to build a more sophisticated model and take into account some additional factors. Obviously a highway to a parking lot is the fastest method to travel from point A to point B, but the objective is not pure speed here. The goal is to create an environment in which both cars and pedestrians can co-exist. In that case, the artery creates a big disadvantage.

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