A driverless vehicle, which will be used to ferry holidaymakers and luggage around at Heathrow airport, has been unveiled. The personal rapid transport (PRT) which will start service at Heathrow Airport next year, is a four-passenger vehicle that can reach speeds of up to 25mph. Advanced Transport Systems (ATS) in Bristol developed the system with 500,000 passengers expected to use it every year. The PRT, which can make the journey from Heathrow's Terminal 5 (T5) business car park to T5 in three to four minutes, was on display at the Science Museum. Professor Martin Lowson, the inventor of the PRT, said: "We believe that our PRT system can transform cities in the 21st century to provide the optimum form of environmentally friendly urban transport, relieving congestion and reducing emissions."