Tuesday, May 4, 2010

New Divisadero With Inconsistent Crosswalk Design: Does SF Need "Great Crosswalks" Standards?


When motorists intrude into crosswalk: Divisadero and Fell Streets

BIKE NOPA note: Reader Jeff Gibson has conducted an impressive analysis of the new crosswalk designs along the Divisadero corridor. He focused on the pedestrian "refuges" or islands meant to give individuals a safe haven in the middle of wide streets. He is especially concerned that crosswalks like the east-west crossing at Divisadero and Fell actually remove full crossing space from pedestrians and that walkers often have to scramble around vehicles to walk through the designated passage. Individuals using wheelchairs or who have difficulty with curbs might find this situation more hazardous than before. Jeff agreed to share his review with BIKE NOPA readers. The descriptions and photos that follow are from his email message.

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I've photographed each crosswalk on Divisadero from Haight to Geary. I can't discern the guidelines under which these crosswalks were designed. There are a variety of configurations so it's obvious no single standard was applied -- not a bad thing necessarily but the logic for some of these designs escapes me. Below are a series of photos with my comments.

photo #1: looking East across Divisadero at Fell, from the SW corner

This prompted my initial query to Kris Opbroek @ DPW (Great Streets Program manager for the Divisadero improvements). I asked why the pedestrian pass-thru at the median was less than half the width of the crosswalk. Her response was that this was a safety feature to protect peds from left turning traffic (from Fell onto southbound Divisadero).

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photo #2: one block South, looking West across Divisadero at Oak from the NE corner

Here we have the exact same situation as at the Fell / Divisadero intersection: a one way street with cars in the left lane able to turn left onto Divisadero. Yet this crosswalk has no thumbnail and peds have the full width of the crosswalk from curb to curb. Why the inconsistency?

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photo #3: Divisadero at Oak (same intersection as #2), looking East from the SW corner

There is a thumbnail here where one wouldn't expect it, at least in the context of safety issues expressed by Kris Opbroek. Traffic on Oak is one way heading East, so there is no possibility of left turning traffic from Oak onto southbound Divisidero (the only scenario in which a thumbnail would come into play). Was this thumbnail supposed to be placed in the north crosswalk at this same intersection? (see photo # 2).

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photo #4: Again one block further South, looking East across Divisadero @ Page, from the SW corner
Here we have what I call a "floating" thumbnail. Is there some sort of design criteria that says a pedestrian pass-through must be no wider than 5 or 6 feet? (I actually did not measure, but they all looked to be the same width no matter the placement / configuration). Why could this thumbnail not be placed at the left margin of the crosswalk? Indeed, if these thumbnails are supposed to be a barrier against car traffic I don't see the wisdom of having half the available crosswalk space between the thumbnail and moving traffic.

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photo #5: looking East across Divisadero at Turk, from the SW corner

Here the thumbnail extends a bit outside of where the left crosswalk line will be painted, but the median somehow gets pulled to the left to extend into the pass-through. Why? As I said before, it seems the designers operated under the idea that pass-throughs can only be X number of feet wide and not an inch more. Another example of this can also be seen in photo #3. Very curious.

The examples above represent only a few of the intersections from Haight to Geary. Most to me have design quirks that have me wondering what the planners were thinking. Thumbnails, for example, appear in a variety of positions in various crosswalks, and the crosswalks at Fulton and O'Farrell are narrower than the rest. Given that every square inch of the final design was thoroughly considered, I wonder why the crosswalks turned out the way they did. There are of course far more egregious examples of poor pedestrian design throughout the city, but with the inclusion of Great Streets principles in this particular project, I would have expected better. Perhaps we need to ensure that "Great Crosswalks" criteria are integral parts of Great Streets.

5 comments:

  1. Actually, the draft San Francisco Better Streets Plan does have guidelines for "Pedestrain Refuge Islands" and it calls for the pass-through to be the entire width of the striped crosswalk and for the thumbnail to extend into the intersection outside the crosswalk area wherever possible. This is covered on pages 123-124: http://www.sf-planning.org/ftp/BetterStreets/docs/Draft_BSP_5_Street_Designs.pdf

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  2. Steve: This morning I sent an email to DPW supervisors of the Divisadero Corridor project with a link to the blog post. I look forward to their response and hope they will clarify the variations in crosswalk island design.Expect an update.

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  3. For Steve Smart from Jeff Gibson (from request to post to me): "Thanks for the link."

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  4. Although it is not necessarily an answer to your question about why the pass-thru distance varies between the different thumbnails, I would guess that the north crosswalk at Oak is missing the thumbnail because of turning radius issues from eastbound Oak to Northbound Diviz and from southbound Diviz to Oak. The thumb on the south side would still provide refuge for pedestrians (albeit an unpleasant one) in the case of s/he not having time to cross Divisadero before the north/south light turned green again.
    The set back of the other thumbs might also have to do with turning issues at the intersections.

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  5. Todd: that sounds very possible for Oak and Divis with the traffic configuration there; with so many variations on one street however it stretches any idea of a standard arrangement.

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