A Segway is a two-wheeled, electric-powered personal transporter unveiled about ten years ago.
Gyroscopic sensors are used to detect when it is tilting and motors then rotate the wheels to keep the Segway upright.
The vehicle is controlled as the rider simply leans forwards or backwards for acceleration and left and right on the handlebar to steer.
Segways are driven by electric motors and can hit up to 12.5 miles per hour.
They are virtually silent, emission-free and can be charged from a wall socket.
In the UK, it is illegal to drive a Segway on the road or even on pavements or cycle paths. They can only be used on private property, despite campaigns to let them be used on cycle paths.
In the U.S., the Segway can be driven on pavements in 30 states. Some states also allow them to be used in bicycle lanes or on roads with speed limits of up to 25mph.