cheese bus

noun2

1. •
   A bus that transports cheese from the factory to retailers.

   • Distribution and sales are maintained with the help of a "cheese bus", which covers eleven routes, each of which take two days. — 1955
2. •
   (slang, offensive) A yellow school bus, especially the smaller kind that is used to transport students with special needs.

   • He was singing what he had been humming earlier that morning, first quietly, then as loud as he could: If you ride on the short bus clap your hands If you ride on the cheese bus, clap your hands. — 2007