A San Francisco MUNI "Trolly Coach", which is basically a stretch bus that uses the overhead power lines, and seats way the hell more than 20 people. (And these things have been in service since 1935.) AND YOU CAN SEE OUT OF THE GODDAMN THING IF YOU WANTED.
https://soc.jrconlin.com/system/media_attachments/files/113/297/483/380/559/763/original/a8894c81b100d595.png