Two years of frustrating speed limits and roadworks will end after this weekend, when drivers are allowed to use the former hard shoulder of the M25 motorway past Potters Bar.

The Highways Agency has announced that the M25 section between junctions 23 (South Mimms), and 25 (A10 /Enfield) will open as a four-lane motorway on Monday morning.

The agency started working on the Potters Bar section in February 2013, as party of a long term plan to convert almost all the orbital motorway to four lanes.

Senior project manager John Martin said: “Around £1.7 billion is being invested into roads in the South-East by 2021 with 145 new lane miles of capacity added.

“Most of the work to improve journeys on these stretches in Hertfordshire and Kent/Surrey is complete and we are now testing the new technology.

“We are delighted to be able to open the first part of the northern section ahead of the planned full completion in December 2014.”

The work includes installation of technology to improve traffic flow, which the agency describes as a “smart motorway”.