SFMTA Adds Two Left Turn Bike Boxes in SoMa

New left-turn bike boxes at Eighth and Folsom Streets (top) and 11th and Howard Streets (bottom). Photo: SFMTA

The SFMTA installed left turn bike boxes at two SoMa intersections this week. This type of bike infrastructure, new to SF, debuted at Market and Polk Streets last month with the new contra-flow Polk bike lane.

The new green-backed bike boxes were placed at two intersections where bike commuters often make “two-stage” left turns between bike lanes: Eighth Street for turns on to Folsom Street, and Howard Street for turns on to 11th Street. They provide guidance and visibility, to show where people on bikes should stop and wait for traffic signals to change.

“Making a left turn across several lanes of traffic isn’t always the easiest thing to do, especially for people who are less confident on their bike,” said SFMTA Livable Streets spokesperson Ben Jose. The turn boxes should make two-stage turns “more easy, safe and comfortable for people of all ages and abilities.”

The SFMTA said the boxes were funded by a grant from People for Bikes, a national bike advocacy organization. Left-turn bike boxes are featured in the SFMTA’s “Innovative Bicycle Treatment Toolbox,” drafted two years ago, and largely based on the National Association of City and Transportation Officials’ Urban Bikeway Design Guide.

Jose said the SFMTA “will be evaluating the measures on the ground, and observations will guide future implementation.”

A left turn at Eighth and Folsom in action. Photo: SFMTA
  • Matt Laroche

    I commute down 8th to Folsom, usually making a box turn, and this is a nice addition.

    (Of course, I wouldn’t mind actual protected bike lanes on 8th & Folsom, but I’ll take this paint for what it is)

  • BBnet3000

    Meh. They dont encourage two stage turns in bike friendly countries.

  • Gezellig

    Two-stage turns are well-known as part of the toolkit in bike-friendly countries. It’s just they should be better protected than Copenhagen Lefts, which leave much to be desired. It’s all about the Dutch Left!


    When appropriate cycletracks at roundabouts eliminate the step 1/step 2 thing, though that requires a greater reworking of streets:


    But with good design and smart signalization even the protected 4-way intersection flows pretty nicely for bikes. Also note that in such designs your right turns are always a freebie right-on-red which is not the case with standard designs. In standard US designs even right-on-red turns currently require a step.

  • BBnet3000


    Id be glad to accept the junction in the video though if they bothered with the light timings.

    This box though, is really quite poor.

  • Gezellig

    Yup! The box leaves much to be desired.

    David Hembrow’s assertion that the most common intersection treatment in the NL is no treatment at all (due to the many many minor residential intersections) is factually correct but of course the matter at hand is how to treat big-road busy intersections, which are a minority of intersections overall anywhere but have disproportionate importance.

    I see the 4-way protected intersection as a more attainable goal for many American cities and have to say that having lived in Amsterdam where 4-way protected intersections are quite common (roundabouts are relatively rare in Amsterdam except for newer outlying suburban areas) they still work great overall. The smart signalization component is key.

    Thanks for the link–also love the Before and After of Assen from the 70s and Now!


    I think it’s often too easy for people to dismiss the Netherlands as Well That’s Exotic Medieval Europe It’ll Never Work Here when actually they’ve changed their environment from one that often looked quite car-crazy American in the 70s (and had even worse fatality rates at the time) to what they have today.

  • Those photos of Assen are great. Thanks for sharing.

    I will use those box turns (I already have been doing that exact maneuver informally — I guess this makes me “legal”) but also will keep pushing for the Dutch Junction to become the norm.

  • coolbabybookworm

    I’ve been doing this without the box when there’s have traffic and some times right-on-red turners get mad at me if i’m in the way, but now it’ll have more legitimacy. Nice to see.

  • Gezellig

    Thanks to BBnet3000 for the link! We should save those Before and After pics for the next time someone pulls the Well That’s Exotic Medieval Europe card. Btw, living there I found a few Befores which are still, well, Befores:

    The attached image is a freeway-esque road which to this day slices through a very central Amsterdam neighborhood, cutting off quaint residential streets from each other. It’s not fun to cross. To my annoyance it was an impediment to getting to the street I lived on by foot or bike. I’m sure it’ll be road-dieted at some point but to do this day occasionally you still do come across relics like this of their very real 50s-70s-era Cars First era.

    Some more evidence:

    –> Central Utrecht parking crater in the 70s:


    –> The central square in Delft was a parking lot until as recently as 2004:


    –> Big box stores and shopping centers with huge setbacks and abundant parking alongside freeways are still a thing today in the Netherlands:


    I could go on and on but all this is to point out that the process is still going on in the Netherlands and development-wise they’re still pretty crazy about their cars–a lot of these images could be from the US. They’ve just found ways to adapt the street level to bikes by cycletracks and the like. This is especially encouraging for US infrastructure because there are actually a lot of similarities.

  • Gezellig

    For some reason this image didn’t stick in the post above. Also excuse the fact that some of the images in the post above seem to be out of order–Disqus sometimes does that for attached images.

  • Gezellig

    That’s in the Netherlands, btw, *not* the US (!).

  • Andy B from Jersey


    Believe or not we teach two-stage left turns in the Traffic Skills classes. I always say discretion is the better part of valor.

  • rlrcoaster

    WTF?! Only someone who is suicidal would do that. I use the crosswalk.
    I also see idiots riding the wrong way on Folsom. Folsom is now so congested you can see enraged drivers. Way to go, to create even more road rage and animosity towards cyclists.

  • Uh…only someone suicidal would make a square left?? You’ll need to explain the immanent dangers.

  • Uh. Except everywhere there’s a separated bike path in Copenhagen, Arhus, Scanderborg, Amsterdam, Rotterdam, Antwerp, Ghent, Bruges, Kortrijk, and Brussels?

  • SFnative74

    Did you read this blog? The person is actually very skeptical of the design! From the blog you link to: “Versions of this junction “design” now pop up everywhere. They’ve even
    reached the opposite side of the planet.. Unfortunately, as the idea
    that this is somehow a good design has taken hold, many of the key
    points of the real design and of Mark’s argument were lost.”

  • murphstahoe

    Folsom is now so congested you can see enraged drivers

    Anyone who reaches “enraged” because of congestion should head over to the DMV and turn in their license.

  • Gezellig

    I think BBnet3000’s intent in posting the link was in fact to point out David Hembrow’s thoughts on the design. For what it’s worth I responded to those points below.


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