I remember one time on the bus a commuter had his full sized bike in the bus. This was a full sized with plenty of space bus, so it wasn't really in the way at all. The bike rack was full and it was a summer day. So probably the guy figured he may as well just try bringing it on instead of waiting another hour for a bus and hoping there's space.

Anyway one busybody got all uppity. But the driver and rest of the passengers didn't care. So it was fine.