Highways Agency

The Project

The M25 Junction 28 / A12 / Brook Street Interchange carries very high volumes of traffic particularly during peak periods. The major flow is between A12 north-east and the M25 south-east and this leads to congestion within the junction and unreliable journey times. A major improvement to the junction involving dedicated free flow slip roads was one of the recommendations of the London to Ipswich multi-modal study which reported in November 2002.

Based upon this study, a scheme to improve journey time reliability and safety through the junction entered the government's Programme of Major Schemes in March 2005.

In November 2006 we published an Environmental Statement and invited comments about our proposed improvement. In February 2007 these comments were submitted along with the improvement proposals to the Secretary of State for Transport. On 4 April 2007 our Scheme was approved. 

What did the scheme involve?

We have now:

• Widened the slip roads on the approaches to the junction 
• Provided a new dedicated left-turn lane from the M25 clockwise exit slip road to the A12 entry slip road (towards Chelmsford and Ipswich) 
• Extended the A12 merge lane towards Ipswich 
• Carried out other minor works to improve safety

We are making these changes within the existing highway land. The improvements to the junction will complement the scheme for widening of the M25 between Junctions 27 and 30 from three to four lanes, which is also in the Programme of Major Schemes.

A map of the new planned layout is available in the Contact Information and Map page.

Where was the work carried out?

Work took place at Junction 28 of the M25 where it crosses the A12. The A12 is the main route linking Ipswich and Chelmsford to London. The junction also connects to the A1023 (Brook Street) which links traffic from the Brentwood area to both the A12 and M25.

What are the benefits?

Benefits from the scheme include:

• reduced congestion at the busy junction
• improved safety through the junction
• improved signing
• improved access to the local area, supporting regeneration and economic prospects
• improved visual aspects as a result of new planting
• all work to be carried out within the existing highway land (no changes to land use, no demolition of property and no loss of development land)
• coordination with the delivery of the future M25 Widening
• environmental improvements

When did the work take place?

The work started in late May 2007 and was open to traffic on the 10th of March 2008.

Why was it necessary?

During morning and evening peak hours over 7,000 vehicles travel through the junction each hour, causing major congestion.  Traffic joining the A12 towards Ipswich has difficulty merging with traffic already travelling on it. The schemes aim was to reduce congestion, improve journey reliability and improve safety at the junction.