S-curve light: meet a chicane

Traffic calming measures can take many shapes and have varying results. 

  • Classic speed bumps slow cars down, but only at the bump. Speed humps do the same but have a slightly higher maximum speed limit, and are easier on your derrieres.
  • Bulbouts or curb extensions slow traffic due to a perceived street narrowing. (they also shorten the crossing for pedestrians.
  • Chicanes achieve traffic slowing like a speed bump or speed hump, but through staggered mini curb extensions that force cars to turn slightly. The slight turning requires slowing down.

New chicane on Elgin Park Street just north of Duboce Street (looking north).
We've seen very few in America and none in San Francisco until now. Elgin Park Street, a narrow one-way street between Market Street and Duboce Street in Mint Slope (or Northwest Mission or Mint Heights, or Deco Ghetto) now has a new and modest chicane. After nearly 10 years of discussing the idea through planning associated with Octavia Boulevard and the Central Freeway, then neighborhood has successfully advocated a traffic calming wish enough for the city to implement it.

The chicane was added due to concerns and the street attracts many drivers "passing through" trying to get from Market to the Freeway, and use the street in hopes of entering the freeway via Duboce. As shown in the photo, the street only has parking on one side, and is posted at a 15 mph speed limit. Our experience shows that many cars travel over the 15 mph limit on these streets, so a chicane is a very good thing.

If only traffic calming wishes and advocacy didn't take 10 years to enact, our city would be in a much "calmer" and safer state.  Let's see how well it calms.


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