Generally, the short bus is a smaller version of a regular school bus that carries mentally challenged students to school. On rare occasions, if your school board is a bunch of assholes (like mine), you will be forced to ride in a short bus for field trips if you class contains less than 18 students.
Teacher: We'll all be going on a trip to the art museum Friday!
Class: Hooray!
Teacher: And we're taking a short bus!
Class: ............
Time: Passes
Class: *is riding the short bus on the highway*
Other cars: *point and laugh*
Class: *is mortified*
The bus i rode to school. Its a little bus for the special kids. We had lots of fun on that bus and you make good friends. People sometimes make fun of it but its really a cool bus. Its yellow.
"The short bus picks up my neighbour's kid every morning. He looks like that banjo boy from 'Deliverance.' In other news, I have a first-class ticket to hell."
The idea of 'riding the short bus' is used in American English in much the same way that 'æåëòûé äîì' (yellow house) is used in Russian as a reference to mentally retarded children. United States public school systems have an extensive bus program to transport children to and from school. Regular buses hold large amounts of children. Shorter buses are typically used for "Special Education" (i.e., the mentally retarded) public school students who are typically educated in different facilities.
Oh don't mind Jimmy here being late - Marina and I took a cab, but Jimmy's a little slow so he had to wait for the short bus.
Dave rode the short bus to school, and got to use the PA system, until he barked at one girl, who was a total dog. He was then told to sit in the back of the short bus, which in all actuallity wasn't that far back.