Airports of London runways. Due to the location in London's western suburbs, Heathrow has had trouble trying to expand, with various expansion projects being cancelled.) As a result, the airport consistently runs at over 99% capacity and is often included on lists of the worst-rated airports in the world. However, on 1 July 2015 Heathrow's expansion plan was suggested as the best option by the Airport Commission and on 25 October 2016 a new northwest runway and terminal was approved by the Government. The airport is connected to Great Britain's motorway network via the M4 and M25 motorways, to London Paddington station by
Automation of the London Underground to open and close doors, and to assist in case of emergency. This method of working will be extended to the other lines by 2022 and will also be used on Thameslink and Crossrail. There are already driverless trains in operation on London second rapid transit system, the Docklands Light Railway (DLR), although this is a relatively newly built system. Boris Johnson promised in 2012 that there would be driverless Tube trains within 10 years. During his campaign to be re-elected as London Mayor, he said "TfL (Transport for London) will rapidly establish a timetable for introducing the first driverless