The old Marmon trolleybuses in SF were big, slow (probably topped out at no more than 25mph), rough (felt every bump in the road) beasts but worked fine for stop n go routes. Typically used on the Market, Mission District, and Van Ness lines (Twins went elsewhere). They had a fun feature: a "booster" button. From the way it worked, it probably hooked the motor up temporarily in series (normally series-parallel or parallel). With some drivers: as everybody's piling on during the afternoon school rush, "move to the back of the bus ... move to the ..." etc. Close the doors, push the button (had to hold it; not latching), and floor it. 0-5 in one big jerk. You are now in the back of the bus.