The Segway claims to be the first self-balancing electric transportation device. Developed by inventor Dean Kamen, the two-wheeled Segway uses gyroscopes, tilt sensors, computer processors, and electric motors to remain upright while carrying a rider.
The technology grew out of Kamen's earlier iBOT mobility project, a self-balancing wheelchair. Segway Inc. was founded in 1999, and the device was publicly unveiled in December 2001 after a highly publicized period of secrecy surrounding its development. The first customer deliveries followed in early 2002.
Riders control movement by shifting their weight: leaning forward makes the Segway move ahead, while leaning backward slows or reverses it. Turning is controlled with a handlebar-mounted mechanism. The company's wording is important here: "first" is a corporate claim about its category, not a claim that no earlier balancing machines or electric vehicles existed. The Segway became the best-known example of a self-balancing personal transporter and inspired later scooters and similar devices.