11/20/2012 03:24 pm ET Updated Jan 20, 2013

Map: All The Billboards In Los Angeles (With Or Without A Permit) | Environment | SoCal Connected | Shows | KCET

Last week the Los Angeles Department of Building and Safety quietly posted the location and permit status of every billboard structure in the city, and an early analysis shows that nearly 10 percent have no permit on file.

In addition, roughly a third of the 5,874 billboard structures in Los Angeles were reported by the city's own inspectors to have possible code violations.