Fewer Muni Stops
Muni is the slowest bus system of any major city in the US. This contributes to the high cost of operating the system. One potential solution is to reduce the number and density of stops on some lines. I think a lot of SF residents would be willing to walk one extra block if it meant Muni ran much faster and cost less money to operate. If you've ever ridden the 5 or the 21 towards downtown, you know how ridiculous it is to have to stop at every block. Just reducing stops to every other block would make a huge difference.