Monday, June 6, 2011

Improving Pedestrian Design

A couple resources for planners and engineers hoping to improve roadway design to better accommodate pedestrians and bicyclists:

First, from the Journal of the American Planning Association, Designing for the Safety of Pedestrians, Cyclists, and Motorists in Urban Environments. In this article, the authors probe at one of the underlying premises that leads to today's emphasis on "vehicle-oriented" roadway design: wide roads are safe roads. Opening with this disturbing quote, "...every effort should be made to use as high a design speed as practical in the interests of safety," from the 2004 AASHTO "green book" (one of the primary guides for American roadway design), the article proceeds to debunk the theory that vehicle crashes are the result of random error and thus roads should be designed to be as forgiving (read: fast) as possible. Obviously such an attitude presents some concerns for vulnerable road users like pedestrians, who are much more likely to be killed or injured on high-speed roads than those where supposedly "dangerous" speed treatments are in place.

While the JAPA article explains why the old theories of roadway design should be thrown out, that doesn't solve the problem of what to do with all the high-speed, pedestrian-unfriendly roadways that have already been built. Enter Caltrans, and its newest complete streets resource, Complete Intersections: a Guide to Reconstructing Intersections and Interchanges for Bicycles and Pedestrians. In it, Caltrans walks through (sorry, the ped puns are hard to avoid) appropriate treatments for each type of intersection, including three- and four-leg intersections, as well as more unique situations like mid block crossings and roundabouts. I particularly appreciate the "Guiding Principles" that Caltrans lays out for intersection design. So often in the past these appear to have been missing from the engineering thought process. Hopefully the new guidance from Caltrans marks a change for the better:
  • Observe (watch how the intersection is currently used)
  • Pedestrians and bicyclists will be there (people will walk, regardless of whether or not an engineer thinks walking is unsafe at a particular location)
  • Maintain and improve (instead of removing pedestrian facilities)
  • Tee it up (to 90 degrees, which forces motorists to make slower turns at intersections)
  • One decision at a time (don't force people to worry about too many things at once)
  • Slow it down
  • Shorten crossings
  • Improve visibility
  • Clarify the right-of-way (because not everyone has memorized the vehicle code like some of us have)
  • Keep it direct (pedestrians won't walk out of their way to get somewhere)
  • Light at night
  • Access for all (including young and old pedestrians, and people with disabilities)

1 comment:

  1. In addition to that,let it be known that it is the law for cars to stop for a pedestrian at a crosswalk. Here in Portland, there are very occasional stings, but the fact is that people are actually blissfully unaware that they need to stop for pedestrians at a crosswalk. They also don't understand what constitutes a crosswalk; many people think it must be striped to qualify. A little bit of education would go a long way to supporting good design and improving crossings where circumstances are less than ideal.