Concerns Raised Over Capacity of Key A12 Junction Near Colchester

National Highways has warned that there are very few viable options to upgrade a critical junction on the A12 near Colchester, as plans for significant housing growth in the area move forward.

The comments come as part of consultations on the borough’s emerging Local Plan, which outlines proposals for development between 2033 and 2043, including the delivery of more than 22,000 new homes.

According to National Highways, Junction 26 at Eight Ash Green is already operating close to its maximum capacity. The organisation indicated that any additional development in the area would likely require major upgrades to both the A12 and the A120 corridors.

However, the report suggests that opportunities for physical improvements at the junction are highly constrained. As a result, future development may depend on whether traffic queues—particularly on slip roads—can be effectively managed.

If suitable mitigation measures cannot be identified, National Highways has indicated it could formally object to the plans on safety grounds.

The concerns extend beyond a single junction. The strategic road network around Colchester, including the A12 and A120, is described as already heavily constrained, with limited ability to accommodate further demand without significant intervention.

The report also highlights that planned housing allocations, particularly around Marks Tey, could further restrict the potential for future infrastructure upgrades by limiting available land and reducing operational flexibility.

These issues are expected to form part of ongoing discussions as Colchester Council continues to develop its Local Plan.