A new signalling system which could reduce overcrowding on the Tube is being tested on Tuesday.
Signals from cables would pinpoint trains to within millimetres
The system uses computer technology which, if successful, would allow trains to run closer together and therefore increase frequency.
It involves an antenna, fitted beneath each London Underground (LU) train, which send signals to the track via cables on the line.
This then allows position of the train to be pinpointed to within millimetres.
The system would first be used on the Jubilee, Piccadilly and Northern lines.
Dr Siv Bhamra from Tube Lines, one of the underground maintenance contractors, told BBC London: "When implementation is complete using modern technology it will be possible to substantially reduce crowding by allowing more trains to run together safely at much higher speeds than is possible within the constraints of existing signalling equipment.
"This is a proven, in-service technology and part of the testing we are doing today is to make sure it doesn't go wrong."