After the Los Angeles artist Richard Ankrom missed his exit off California Highway 110 one too many times, he decided to indulge in a little "guerrilla public service." Ankrom crafted three reflective sign components—a number 5, the word "North," and an arrow—and artificially aged them. He also whipped up an authentic-looking California transit authority uniform. On August 1, 2001, he shimmied out over the freeway in broad daylight and used his unique artwork to tag the tricky left exit to Interstate 5 North.
For nine months, no one noticed that the change was the work of a private citizen. Ankrom eventually leaked the story to a local paper. The sign was reviewed in the Los Angeles Times as art, and the locals enjoyed its functionality. The most unexpected reaction came from the California transit authorities: They left Ankrom's civilian sign in peace for eight more years. It's a rare day when performance art yields something useful, rarer still when public officials leave such a thing unmolested.
In November 2009, the highway authority took down the whole structure during routine maintenance, tragically destroying the signed original piece in the process. But then it paid Ankrom's work the ultimate compliment, incorporating his edits into the new, official sign.
Katherine Mangu-Ward (email@example.com) is a reason senior editor.