Around 10,000 more tube passengers per hour will be carried on the District Line when work to improve frequency and reliability is completed by Transport for London (TfL).

TfL engineers reached a milestone at the weekend when they completed a major test of a new computer-based signalling and control system between Hammersmith and Edgware Road.

The system will allow trains to run closer together, meaning a more frequent service and shorter waiting times for customers on the District Line.

Mark Wild, London Underground’s managing director, said: “Great progress is being made and, as early as next year, customers will start to see improved reliability and the most up-to-date customer information as the signalling is introduced.

“This programme is an important part of our multi-billion-pound investment to overhaul some of the oldest parts of the Tube and improve journeys for our customers.”

Similar technology - enabling thousands more passengers can be carried each hour - is already used on the Jubilee and Northern lines and the famously fast Victoria line had its signalling system improved last May.

The signalling upgrade will eventually bring more frequent and reliable journeys to forty per cent of the London Underground network, including:

• 17,500 more customers per hour on the Circle and Hammersmith & City lines,

• 10,000 more customers per hour on the District line

• 9,000 more customers per hour on the Metropolitan line

French engineering company The Thales Group was also involved in the works at the weekend.