M4 junction 12 at Theale

Published: 12 March 2026

National Highways will be carrying out essential bridge repairs to junction 12 of M4 Theale Interchange in March.

Works will require overnight closures to both east and west of the junction including the on slip/off slip roads to the M4 between the hours of 9.00pm and 6.00am.

• Thursday 19 March for two nights – eastbound exit slip closed
• Monday 23 March for two nights – westbound bridge and entry slip (lane closure on eastbound exit slip)
• Wednesday 25 March for two nights – eastbound bridge and entry slip (lane closure on westbound exit slip)

A fully signed diversion will be in place during the closures.