Two wheel transportation is a term used to describe any form of transportation that uses two wheels. This includes bicycles, motorcycles, and scooters. The most common type of two wheel transportation is the bicycle, which has been around since the 19th century and is still widely used today. Motorcycles and scooters are also popular forms of two wheel transportation, with both being used for recreational and commuting purposes. The crossword solution for two wheel transportation is 'CYCLE, ' which is an appropriate term for all types of two wheel transportation.