Probably a Blue Bird body with a GMC or Chevrolet chassis. Blue Bird used to put their badge on the hood sometimes, in place of the GMC or Chevy badge. I don't think the hood slopes enough for it to be a Vision.
edit- and the "Gasoline Only" confirms this as I dont think the Blue Bird Vision is availble with a Gasoline engine... the GMC and Chevy chassis I think is the only chassis with a Gasoline engine after 1990 or something.
also the stop sign on the right side is a mistake (or actually a joke used for the movie)
Yes it's a joke in the movie.
The peter parker type character in the movie called 'Rick Riker', runs for the bus, bashes his head into the mirror, get's up and get's hit by the stop sign and is then knocked by the doors opening.!