M25 Traffic Lane Closure: Severe Weekend Delays Expected As Major Upgrade Works Enter Critical Phase
Drivers on the London orbital motorway face significant travel disruption this weekend as a critical m25 traffic lane closure goes into effect. National Highways has issued an amber traffic alert, warning motorists to expect severe delays between Junction 10 (A3/Wisley) and Junction 11 (Chertsey) due to essential bridge deck installation and resurfacing works. The targeted restrictions are expected to cause tailbacks stretching several miles, impacting outer London commuters and those heading toward Heathrow and Gatwick airports.
| Affected Stretch | Closure Type | Start Date/Time | End Date/Time | Expected Delay |
|---|---|---|---|---|
| M25 J10 (Wisley) to J11 (Chertsey) | Multi-lane closure & slip road shut | Friday, Aug 7, 10:00 PM | Monday, Aug 10, 6:00 AM | 45–60 minutes |
| M25 J25 (Enfield) Clockwise | Single lane restriction | Saturday, Aug 8, 8:00 PM | Sunday, Aug 9, 6:00 AM | 15–20 minutes |
| M25 J5 (Sevenoaks) Slip Road | Full overnight closure | Sunday, Aug 9, 10:00 PM | Monday, Aug 10, 5:00 AM | 20–30 minutes |
The Wisley Bottleneck: Driving Force Behind the August Restrictions
The current lane closures are part of the ongoing £317 million Wisley Interchange upgrade scheme. This massive infrastructure project, designed to improve safety and increase capacity at one of the UK’s busiest motorway junctions, has entered its final major phase in August 2026. Contractors are utilizing this weekend's window to install critical gantry structures and complete vital resurfacing across the newly configured lanes.
National Highways project managers estimate that once completed later this year, the upgrade will reduce accidents by up to 30% and significantly smooth the daily flow of over 300,000 vehicles. However, reaching this milestone requires temporary pain for drivers, with lane capacity reduced by half on the clockwise carriage between Surrey and the Thames crossing points.
Navigating the Disruptions: Key Diversion Routes and Peak Hours
To minimize time spent in gridlock on Saturday, August 8, 2026, and Sunday, August 9, 2026, transportation analysts advise avoiding the southwestern quadrant of the M25 entirely if possible. Peak congestion times are projected to fall between 10:00 AM and 6:00 PM on both days.
For those who must travel, the following official diversion routes have been established:
- Clockwise Diversion: Exit at J10, follow the A3 northbound to the Painshill Interchange, take the A245 toward Byfleet, and rejoin the M25 at J11 via the A320.
- Anticlockwise Flow: Though remaining open, this direction will be down to two running lanes, creating secondary bottlenecking near the Cobham Services.
- Airport Travelers: Passengers heading to Heathrow Terminal 5 or Gatwick should allow an additional 90 minutes of travel time or utilize the rail network.
Why is the M25 closed again this weekend and how bad is the traffic ...
The Road Ahead: Next Phase of M25 Infrastructure Upgrades
As the current weekend closures wrap up on Monday morning, focus shifts to the remaining autumn schedule. National Highways has confirmed that further overnight lane closures will be required throughout the rest of 2026 to finalize the safety barrier installations and complete the local environmental planting schemes.
With the Wisley project nearing its slated December completion, drivers can expect a gradual reduction in scheduled weekend closures. However, localized maintenance schedules will continue to target resurfacing needs across the northern stretches of the M25 through the winter months. Commuters are highly encouraged to check real-time telemetry updates before starting their journeys.
