That means,for example, working to improve the city's transportation system with more wheelchair accessible taxis, and providing working elevators for the subways and motorized lifts for buses.

VOA: standard.2010.07.27

So it was the primary means of public transportation

所以它是这里最初的主要公共交通工具，

旧金山的公共交通 - SpeakingMax英语口语达人