A single-track vehicle is a vehicle that leaves a single ground track as it moves forward. Single-track vehicles usually have little or no lateral stability when stationary but develop it when moving forward or controlled. In the case of wheeled vehicles, the track of the front and rear wheel usually follow slightly different paths when turning or when out of alignment.
Single-track vehicles have unique dynamics that, in the case of wheeled vehicles, are discussed at length in bicycle and motorcycle dynamics, that usually require leaning into a turn, and that usually include countersteering. Single-track vehicles can roll on wheels, slide, float, or hydroplane.
- the bicycle and all its varieties, such as tandem, tall, and recumbent
- the motorcycle and all its varieties, such as scooter and feet-forwards
- the kick scooter and all its varieties
- the unicycle and monowheel
- the inline skate and roller ski when only one is in contact with the ground or when the second follows behind the first
- the snowboard and monoski
- the skirider
- the ice skate when only one is in contact with the ice or when the second follows behind the first
- the skateboard and all its varieties, such as the snakeboard
- the surfboard
- the caster board when the rear wheel closely follows the front wheel track
- the Uno dicycle