Other critics claim that Metro Rapid is a triumph of marketing over substance. For many years, Metro and its predecessor, the SCRTD, operated "limited"-stop routes, which were similar to Metro Rapid service in the middle of their routes (serving only transfer points and major stops), but made local stops at each end. Rapid buses do not change traffic signals outside of the City of Los Angeles because only the City has tied the transponders to the signal network. The Los Angeles County Department of Public Works is working on rectifying the problem for all the other cities where Rapid buses pass through, but individual signals have to be reprogrammed to give signal priority to Rapid buses. In addition, only Rapid-branded buses have transponders, which causes problems when not enough Rapid buses are available (or conversely, when Rapid-branded buses are used on Local service).