M25 J28 Improvement

Scheme outline

Improvements to M25 junction 28, the interchange with the A12 and A1023 west of Brentwood, to alleviate congestion that is currently a frequent problem. The existing junction is a Three Level Stacked Roundabout but extremely high volumes of turning traffic make the signalised roundabout a serious problem.

The preferred route, announced in summer 2017, is option 5F which will provide a very large looped sliproad from the anticlockwise M25 to the eastbound A12. New bridges will allow it to cross the existing sliproads to and from the roundabout.

Other options for the junction included a second new free-flowing sliproad from the A12 westbound to the M25 anticlockwise, which would have removed the other problematic right-turn movement from the roundabout, but it's predicted that the one loop now proposed will remove sufficient conflicting traffic flows from the roundabout that the other sliproad will not be necessary for some time. If traffic levels continue to rise, the present works would not prevent it being added later.

In preparation
Junction improvement
with parts under motorway restrictions
Highway authority


23 January 2018

Between November 2016 to January 2017, a public consultation was carried out to gather feedback on proposed plans to improve junction 28 on the M25. Following an in-depth analysis of the work, Option 5F has been selected as the preferred option.

Works are to commence either in 2021 or 2022.

More information


With thanks to Sam West for information on this page.