Work began this week on a major upgrade to one of the busiest junctions on the M25.
Junction 28 features a roundabout mainly controlled by traffic lights and connects the orbital motorway with the A12, as well as providing local access to Brentwood via the A1023 (Brook Street).
National Highways said that up to 7,500 vehicles an hour currently travel through the roundabout at peak times and it is already operating at capacity, with motorists regularly experiencing congestion and delays.
Work on the 36-month scheme, which is costed at £120m to £150m, began on Thursday.
Main construction work will include:
- building a new two-lane loop road, for traffic travelling from the M25 anti-clockwise onto the A12 eastbound (towards Brentwood). This will include the construction of new bridges to take the loop road over or under the other road links, and the Weald Brook; new signage and changes to the landscape
- changing the position of A12 eastbound exit slip road and M25 anti-clockwise entry slip road to allow for the new loop road
- widening the M25 anti-clockwise carriageway to provide more space for traffic leaving for the A12 eastbound.
National Highways project manager Zach Pepper said: ‘These improvements will provide safer journeys for thousands of drivers, cyclists and walkers who use this route every day as part of our wider investment to enhance capacity at this vital junction.
‘Improving the flow of traffic and allowing more capacity on the exit slip roads will provide a safer and more integrated network for everyone. There will also be less likelihood of traffic queuing back onto the M25 once this upgrade and reconfiguration of the junction is complete.’
The then transport secretary, Grant Shapps, gave the scheme development consent in May, nearly two years after the government-owned company first submitted its application to the Planning Inspectorate, having delayed his decision since December last year.
The scheme is due to be complete by Summer 2025.
