National Highways has detailed the third planned M25 closure of the year, as the government organisation continues work on its £317 million scheme to improve junction 10. 

The closure will last a full weekend from junction 9 (A243 Leatherhead) to junction 10 (A3 Wisley), starting at 9pm on Friday, 12 July and ending at 6am on Monday, 15 July. 

Two more closures will take place at unspecified dates later this year, bringing the total to five. 

It will allow National Highways to install a new bridge on the roundabout at junction 10, having already closed the stretch of road twice to remove a bridge and install a gantry.  

National Highways has warned drivers in the area to expect delays, particularly if heading to Gatwick or Heathrow airports, festivals, concerts or travelling on holiday. 

The junction, which leads drivers onto the A3, is a key road out of London to the south coast and is expected to impact drivers heading to the 2024 Goodwood Festival of Speed. 

In a statement sent to Autocar, organisers of the Goodwood Festival of Speed warned drivers to check their routes before departing for the world-famous motor show. 

“In our pre-event customer communications, we will be advising ticket buyers to check their route before travelling, to follow local road diversions and visit the National Highways M25 Junction 10 website. It may be wise to allow a little more time than planned,” the organisers said.

National Highways says its two previous closures of the M25 have been a “great success”, which is “largely thanks to many drivers avoiding the area and making other travel plans during the closure”. 

Jonathan Wade, National Highways senior project manager, said: “We would urge all drivers to follow the official diversion route as this is the best chance of reaching your destination in good time. Please ignore your sat-navs and follow our diversion route instead.”

Diversion routes for the July M25 closure

National Highways outlined a series of diversions for the July M25 closure. Read on to see the official diversions:

Junction 10 to junction 11

Northbound A3 to Painshill junction, A245 towards Woking, and then A320 to M25 junction 11.

Junction 11 to junction 10

A320 south towards Woking, A245 towards Byfleet and Painshill junction, southbound A3 to junction 10. 

National Highways has also advised drivers that avoiding the closure by taking the M25 via the Dartford Crossing may also be quicker.