After you call your councilmember and report your concern, try the Los Angeles Department of Transportation, as well as the only 2 female members of the Los Angeles City Council.
Los Angeles Department of Transportation (213-580-1177). You can press "0" to speak with an operator and have the opportunity to leave a voice mail.
Councilmember Jan Perry's office (213-473-7009) was extremely friendly and helpful. I strongly recommend that you additionally call this office.
Councilmember Janice Hahn's office (213-473-7015). After being put on hold, I was told that these signs are no longer used. After replying that these signs are up right now, I was told to talk to my own member. Obviously, I have done that, but I felt female councilmembers might care more about this issue.
Read about the Workers Ahead Campaign