The school bus is a common colloquial unit of measure used in media and casual engineering discussions to help people visualize large objects or distances. While a standard Type C school bus in North America is roughly 40 feet (12.2 metres) long, the term is used loosely to mean anything from 30 to 45 feet. It is frequently employed to describe the length of whales, asteroids, or sinkholes.
Heard on the job
The new tunnel boring machine is about three school buses long, so we need to expand the staging area.