Scott Eisen/2013 AP file photoSan Francisco cyclists can take advantage of green bike boxes at intersections to help protect themselves from vehicles.

Dolan: Green bike boxes make intersections safer for all

Bike To Work Day is today and, according to the San Francisco Bicycle Coalition, Market Street is the most heavily bicycled road west of the Mississippi River.

In 2013, four bicyclists were killed on the streets of San Francisco, the highest annual figure since 2001, while 21 pedestrians were killed in 2013. In 2014, 18 pedestrians were killed as well as three bicyclists. In continuing efforts to make San Francisco roadways safer for pedestrians and bicyclists, in 2011 the San Francisco Municipal Transportation Agency began installing green bike boxes at some intersections along Market Street that are meant to safely separate pedestrians, bicyclists and motorists.

Originating in Europe during the 1980s, the green bike boxes are placed at the front of a lane immediately before the crosswalk at an intersection, providing a priority red light waiting area for bicyclists between the crosswalk ahead of them, and motor vehicles behind them. The boxes are meant to provide bicyclists with a safe zone, or buffer, where they can safely wait for red lights to turn green. There is a solid white line at the front of the box and at the rear. When the traffic signal is red, bicyclists approach the bike box from the adjoining bicycle lane along the right-hand side of the roadway and stop within the bike box, before and outside of the crosswalk. By intentionally placing bicyclists at the front of these intersections, bicyclists also become much more visible to the motorists directly behind them while also providing an additional buffer from motorists encroaching into crosswalks.

The theory is that by giving bicycles priority at intersections, in a space not occupied by motor vehicles or pedestrians, bicycles can proceed safely through the intersection when the light turns green, before any motor vehicles pass through the intersection, thus reducing opportunities for bicyclists and motor vehicles to collide with one another. The boxes are intended to fully segregate pedestrians, bicyclists and motorists at intersections and reduce the possibility for accidents and collisions resulting in injury.

When approaching an intersection with a bike box on a red light, motorists must come to a full stop behind the solid white line at the rear of the bike box, and without entering the bike box. Motorists must remain clear of the bike box for as long as the light remains red. Right turns on red are prohibited at these intersections. Once the light turns green, motorists must wait for all bicycle traffic ahead of them in the green bike box to safely clear the intersection and then are permitted to proceed.

After installing four green bike boxes along Market Street in 2011, the SFMTA issued a press release wherein it noted that the boxes were coated with a thermoplastic material instead of regular paint. The thermoplastic material has the added benefit of being reflective, thus making traffic-control devices easier for all to see at night.

San Francisco's bike boxes were the first of their kind in California and the SFMTA continues to conduct studies related to their effectiveness. In the meantime, we must all continue to raise our awareness of pedestrians, bicyclists and motorists, for our safety as well as theirs.

Christopher B. Dolan is owner of the Dolan Law Firm. Email questions to

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