Why Are Street Names Stamped Into San Francisco Sidewalks?

If you look down while walking around Bay Area cities like San Francisco, Berkeley, Oakland and Alameda, you often see the names of the two intersecting streets stamped into the concrete where the sidewalks meet. It can seem … redundant. There are overhead signs after all.

Bay Curious listener Heidi Hagberg got to wondering why we do things this way: “I’ve heard that it’s because of earthquakes and the potential for street signs to fall. Is that true?”

Answering Heidi’s question took us into the weird world of sidewalk stamps, which, it turns out, can be full of mistakes!

And Heidi heard right — it’s because of earthquakes. In 1905, San Francisco officials passed an ordinance requiring that street stamps be used when new sidewalks were built. The ordinance passed before the 1906 earthquake and fire. There were quakes before the big one that probably influenced city lawmakers.

San Francisco’s streets were laid out just before the Gold Rush, but “there were not traditional street signs like we have today,” says Rachel Gordon, the director of policy and communications for San Francisco Public Works. People used buildings as landmarks back then, and city leaders worried that if the buildings fell down, people wouldn’t know where they were after an earthquake.

After the 1906 earthquake and fire, there was a lot of rebuilding to do and lawmakers made sure that all intersections got street stamps.

These days Gordon says San Francisco still stamps street names into sidewalks when intersections are changed or repaired. The Department of Public Works does some of the work itself, but also contracts out sidewalk construction. But there are about 18,000 intersections in the city and sometimes the installers make mistakes — or improvise.

“It’s a hard thing to get right,” says Erica Fischer, who likes to find and photograph quirky mess-ups around the city. “You’re putting the letters in mirrored when you’re trying to stamp it on the sidewalk.”

Some of the wonky stamps are just misspellings, but others show ingenuity. Stampers have used M’s with one arm brushed out for N’s, the number 1 for a lowercase L and so many other weird workarounds.

One of Fischer’s favorites is in the Haight, where whoever did the stamping must not have had an S on hand. Instead, the person used two J’s, one with the hook facing down, and one with the hook up. Meshed together, they make a slanted S.

“There’s lots of those sort of improvised pieces out there,” Fischer says. She became obsessed with them when she made it a goal to walk every street in San Francisco and take photographs of interesting things along the way. Once Fischer started noticing all the funny things stamped in the streets, she couldn’t stop looking for more oddities.

Rachel Gordon with the city’s Department of Public Works says there are fewer mistakes than there used to be. “What we’re supposed to do is have our inspectors go out and make sure that the name is spelled correctly,” she says. “That started to happen a little more frequently when people were making fun of San Francisco for not having all the names spelled correctly.”

Still, with 18,000 intersections there are bound to be some quirks, so keep your eyes peeled!