M3, A34 and A33 closures

National Highways is carrying out essential works that will affect the M3, A34 and A33 as part of an improvements programme.

M3 – full weekend closures

To enable the safe installation of steel beams for the new M3 roundabout bridge decks, the M3 will be fully closed in both directions between junctions 8 and 9 on the following weekends:

9pm Friday 30 January to 6am Monday 2 February 2026

9pm Friday 13 February to 6am Monday 16 February 2026

Local diversion routes can be found here: M3 junction 9 to 8 northbound and southbound diversion.

Strategic diversion for freight, large vehicles and coastal flows

Operators of HGVs, large vehicles and freight travelling to or from the coast are strongly advised to use the designated strategic diversion via the A3. This route is designed to avoid congestion on local roads and reduce delays for long‑distance and commercial traffic.

A34 and A33 – 24-hour southbound closure

Following November’s successful removal of the northern beam at Kings Worthy Bridge, the replacement beam will now be installed. Due to the size and reach of the crane required, a full southbound closure is necessary on:

9pm Saturday 7 February to 9pm Sunday 8 February 2026

A34 southbound from Three Maids Hill

A33 southbound from the Cart and Horses junction

A signed diversion route will be in place via the A34, A303 and M3: A34/A33 southbound diversions.