The SFMTA installed some green-backed bike stencils and upgraded ladder-style crosswalks at Market Street and Octavia Boulevard, the intersection that sees the most pedestrian and bicycle injuries in San Francisco.

Mark Dreger and I were pleasantly surprised to stumble upon the improvements yesterday while riding home from an awesome Sunday Streets in the Mission. The markings should help call attention to people walking and biking through the intersection and reduce crashes while San Franciscans wait for camera enforcement against drivers who make illegal right turns on to the freeway (the use of enforcement cams there was deemed legal in January).

This particular use of green-backed stencils paired with dashed lane markings may also be a sign of the SFMTA’s continued experimentation with intersection markings to improve bike safety. Though the agency has used these types of markings at Market and Van Ness Avenue, 17th and Church Streets, and several intersections along the Wiggle, SFMTA staff has said that their primary purpose is not to make people on bikes more visible to drivers, but to help guide bike riders through intersections. The reason, an SFMTA staffer told me, is because the agency doesn’t have sufficient data to show that bike markings stenciled through intersections are effective at reducing crashes.

The two Market and Octavia stencils are placed only in the eastbound direction at the spot where illegally-turning drivers would intersect with bike traffic, and they seem designed specifically to call drivers’ attention to passing bicycle riders, much like crosswalks do for pedestrians. Or, as Mark put it, the new markings are “cross-bikes.” Perhaps we can expect to see more of this treatment throughout the city.

Update: According to a Facebook comment from a staffer who runs the SFMTA Livable Streets page, the bike markings are intended for both visibility and guidance: “One key goal here is to further discourage illegal right turns by providing an additional visual clue to any motorist contemplating the illegal turn.”

After the jump, photos of another bike upgrade at Baker and Oak…

At Baker and Oak Streets, another SFMTA work-in-progress, Mark and I also spotted a new green bike box on Baker. It was placed at the front of the left-turn lane where eastbound bike riders make the turn on to Oak, where a protected bike lane is in the works. The left-turn lane also has a new buffer zone, apparently to provide some space between passing motor traffic and bike riders waiting to make the turn.

In the few minutes we were at the intersection, Mark and I noticed a distinct change in bicycle riding behavior compared to the previous configuration. Whereas many people on bikes used to prefer making the left turn by illegally riding onto the sidewalk on the left-hand side of Baker, every rider we saw pass by used the newly configured turning lane properly.