This is Bill White with the VOA Special English Science Report.

　　An American inventor, Dean Kamen, says he has invented the world's first self-balancing individual transport vehicle. It is called the Segway Human Transporter.

　　The Segway looks like a long stick with two wheels. The stick has handles for a person to hold. The wheels are connected by a platform. The person stands on the platform and holds the handles. The vehicle moves forward or backward when the person moves his body in that direction. The driver turns the handles to go left or right.

　　The Segway has computers and gyroscope devices to make it move and balance. It is powered by batteries that can be re-charged in a few hours by using an electric outlet. It can travel at a speed of nineteen kilometers per hour. It costs less than ten cents a day to operate. It does not produce pollution.

　　Mr. Kamen says the Segway could replace cars in crowded city centers. He says it was designed to reduce pollution and solve other environmental problems in cities. However, it was not designed to travel on roads.

　　Mr. Kamen is a successful inventor and president of the DEKA Research and Development Company near Manchester, New Hampshire. He has invented about one-hundred other devices. Some are important medical devices. These include an insulin pump for people with diabetes, a device to open blocked blood vessels in the heart and a wheelchair that can move up steps.

　　The Segway will be for sale to the public next year. It will cost about three-thousand dollars. Several businesses are testing the vehicle now. These include the United States Postal Service and the bookseller Amazon.com. Some letter carriers will try riding the vehicles to deliver the mail. Amazon workers will use them to find books in their huge storage buildings. Police in two cities also will test the vehicles to see it they can be used for law enforcement.

　　Some technology experts have criticized the Segway vehicle. They say it could be dangerous to ride. It does not protect the rider from bad weather. They say it holds only one person while other small vehicles can hold three people. They also say people may use the vehicle to avoid walking and getting exercise. However, other experts say the vehicle is interesting and could be used in many ways in the future.

　　This VOA Special English Science Report was written by Nancy Steinbach. This is Bill White.