M25 (J14–17) & M4 (J1–7) – Temporary Road Closures due to Maintenance Works

national highways
M25 (JUNCTIONS 14 TO 17) AND M4 (JUNCTIONS 1 TO 7) MOTORWAYS TEMPORARY TRAFFIC RESTRICTIONS

Notice is hereby given that National Highways intends to make Orders on the M25 and M4 Motorways in the Unitary Authorities of Slough, Windsor & Maidenhead, and Buckinghamshire Council, and the London Boroughs of Hounslow and Hillingdon, under Sections 14(1)(a), 14(1)(c) and 14(7) of the Road Traffic Regulation Act 1984 because works are proposed to be executed on, or in the vicinity of, the road.

The effect of the Order in this area would be, in phases, to:–
1. authorise the overnight closure of –
(a) sections of both carriageways of the M25 between Junction 14 (A3113/Heathrow Spur Road) and Junction 17 (A405);
(b) both carriageways of the M4 between Junction 1 (A4/A205/A315/A406) and Junction 7 (A4);
(c) both carriageways of the M4 between Junction 5 (A4) and Junction 8/9 (A404(M)/A308(M));
(d) all slip and link roads leading to and from the lengths of carriageway described in 1. (a) to (c) above;
(e) the circulatory systems at M4 Junction 3 (A312) and M4 Junction 4 (Heathrow Spur Road/A408), and M4 Junction 8/9;
(f) the hard shoulder adjacent to the lengths of carriageway and slip roads described in 1. (a) to (d) above;
(g) any emergency refuge area adjacent to the lengths of carriageway described in 1. (a) to (c) above; and
(h) the bus lane on the southbound Heathrow Spur road.
2. authorise the overnight use of the hard shoulder adjacent to the lengths of carriageway and slip and link roads described in 1. (a) to (d) above.
3. permit HGVs in the outside lane of the lengths of carriageway described in 1. (a) to (c) above, during inside-lane closures.
4. suspend the bus lane on the southbound M4 Heathrow Spur road to allow the lane to be used by all traffic.

These measures would be in the interests of road safety while contractors undertake maintenance and renewal work of a cyclical nature and M25 and M4 project works.

The duration and scope of each closure or provision above would vary depending on the nature of the maintenance work being undertaken on each occasion. The programme of works would start on or after 2nd January 2026.

Overnight closures on the M4 and connecting roads between Junctions 5 and 8/9 would be in operation between 21:00 and 06:00 (maximum period).

There is a process which would extend the hours below on the M4 between Junctions 1 and 5, and the M25 to between 19:00 and 06:00 (maximum period) on any day, subject to traffic counts and the standard local authority permissions.

The overnight closures for M4 between Junctions 1 and 5, and the M25 would otherwise be in operation between:

Monday – Thursdays: 22:00 – 05:30
Fridays: 23:00 – 06:00
Saturdays: 22:00 – 06:00
Sundays: 22:30 – 05:30

Planned maintenance work would be scheduled to avoid disruption during known peak periods, although essential maintenance may be necessary during these periods to prevent the need for emergency works. Please see National Highways website for specific details on any upcoming closures.

The Order would come into force on 2nd January 2026 and shall remain in force until 24th December 2026.

Traffic affected by the closures would be diverted via other junctions of the M25 and the M4, or by using the M40, A4, A41, A308, A308(M), A312, A355, A404(M), A404, A405, A406, A412, A414, A3044, and A3113. The diversion in operation would vary according to the closure in force, and the diversion roads listed above are the agreed routes, but these may change depending on local conditions.

The temporary closures, hard shoulder and HGV outside lane running, and diversion routes would be clearly indicated by traffic signs when they are in operation during the works period.

I Rosendaal, an Official of National Highways
Ref: NH/SE/2026/M25/RNO, M4/RNO
National Highways, (Company No 9346363).
Registered Office: Bridge House, Walnut Tree Close, Guildford, Surrey, GU1 4LZ. A company registered in England and Wales.
For enquiries, please contact the Customer Contact Centre on 0300 123 5000 or info@nationalhighways.co.uk
www.nationalhighways.co.uk