M25 closures: Junction 10 shut all weekend with no M25/A3 access

Roadworks on the M25 once again threaten chaos for travelling motorists this weekend, as National Highways implements a full closure of Junction 10 on London’s orbital motorway.

Drivers in Surrey will be unable to leave or join the M25 at junction 10 from 9pm on Friday (June 13) evening until 6am on Monday (June 16) morning. The same applies to those using the A3 as the junction for those wishing to join the M25 will also be closed in both directions. 

Both the M25 and A3 will remain open as usual for traffic passing through at junction 10 with only the entry and exit slip roads affected. Diversion routes will be signposted but heavy traffic along them is expected. Associated congestion is also likely to affect other routes close to the affected junction and the diversion routes.

The closure this weekend is the latest in a series that has included five total closures of the M25 in a project costing almost £320m. The works are designed to improve safety and travel times around junction 10 where the M25 motorway meets the A3. No further total closures of either the M25 or the A3 are currently planned. 

The work has involved numerous bridge demolitions, one of which is being replaced with a thoroughfare billed as the UK’s first ‘heathland bridge’ which will be planted to accommodate wildlife as well as pedestrians.

The M25 works were previously planned to end this summer, but National Highways recently announced that the completion date for the Junction 10 project has been pushed back by around nine months to spring 2026.

Why is the M25 closing?

The project at Wisley is set to be completed by spring 2026 at a cost to the taxpayer of a staggering £317million (or perhaps even more now the project’s been delayed), and this series of M25 closures is to allow works that will completely reconfigure the troublesome Junction 10 roundabout where the M25 and A3 meet. 

These closures are the first time the M25 has shut during the daytime since it opened almost 40 years ago in 1986. However, National Highways says the improvements will not only “reduce congestion [and] provide safer journeys for thousands every day”, but also allow the installation of a nature bridge (also known as a heathland bridge) which will let wildlife cross from one side of the motorway to the other safely.

Where is the M25 closure?

National Highways provides official diversion routes for each M25 closure; these will be signposted, with full directions listed on the official project website. If and when a diversion takes drivers through London’s Ultra-Low Emission Zone (ULEZ), those not behind the wheel of compliant cars will not be charged.

Do not use sat-nav to avoid M25 traffic problems

Many motorists worried about traffic problems resulting from the M25 closures will be tempted to use their sat-nav systems to try and find a quicker route, but the official advice is not to do so. Jonathan Wade warned that a previous closure on the A3 had resulted in major traffic build-up in local villages as drivers tried to find their own diversion routes.

"We can't influence people in terms of taking the initiative themselves and just simply following what a sat-nav says, but please follow the signs." He said, going on to explain that there was "probably a greater risk of congestion by people just doing their own thing and thinking they can perhaps beat the signs and find a shorter or quicker route".

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