National Highways Announces Major M3, M27 and M4 Closures

National Highways has scheduled a series of significant road closures and restrictions across several major motorways in the United Kingdom starting October 30, 2026. In Hampshire, overnight closures will affect the M3 and M27 through November 1 to facilitate reconstruction between M3 Junctions 8 and 12, maintenance at Junction 4a, and the removal of hazardous trees at Junction 1. On Sunday, the M3 will close in both directions from Junction 2 to Junction 3, with accompanying closures on the M25 between Junction 12 and the M3 for carriageway repairs.

Additionally, the M3 northbound entry slip road at Junction 9 remains closed as part of a £280 million project to improve links with the A34, which is slated for completion by 2028. The agency has advised motorists to follow signed diversions rather than satellite navigation systems to avoid unsuitable routes.

Simultaneously, National Highways is initiating a long-term geotechnical and maintenance project on the M4 between Junctions 16 and 17. Running from October 30, 2026, until October 4, 2027, the project includes daily overnight closures from 8 p.m. to 6 a.m. and a daytime 50mph speed limit. Certain lane restrictions are also in place for vehicles wider than 2.00 meters. Officials stated these measures are necessary to ensure the safety of the public and road workers.