M25 Junction 12: the M3 at Thorpe
Junction 12 is where the M25 meets the M3, at Thorpe near Chertsey in Surrey. It is a large interchange of sweeping link roads, built so that traffic can move between the two motorways in every direction without stopping at a roundabout.
Live traffic speed flow: M25 Junctions 11 to 13
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Where the roads go
Take the M3 west for Woking, Basingstoke, Winchester and Southampton, or east for Sunbury, where the motorway ends and the road continues into south-west London as the A316. On the M25 itself, the next junction clockwise is Junction 13 for the A30 and Staines-upon-Thames, and anticlockwise it is Junction 11 for Chertsey.
Why it matters
Junction 12 sits just south of the busiest stretches of road in Great Britain. When the Department for Transport counted every stretch of road in 2025, the M25 between Junction 13 and the Heathrow boundary at Junction 14 took the top places. A hold-up here can back up towards those stretches quickly, so it is worth checking before you set off.
For news about the M3 itself, see our sister site M3 Traffic.
M25 Junction 12 at a glance
| Junction | M25 Junction 12 |
| Meets | the M3 (M3 Junction 2) |
| Near | Chertsey and Staines-upon-Thames |
| Next junction clockwise | J13 (A30, Staines) |
| Next junction anticlockwise | J11 (A317 and A320, Chertsey) |
| Traffic news for the M3 | M3 Traffic |
Live traffic news at M25 Junction 12
Live traffic news at M25 Junction 12
Incidents and roadworks between Junction 11 and Junction 13 that we are aware of.
M25 Anti-clockwise Jct 11 exit slip road closure
02:543 Oct 2026reported 2 min ago
- Location
- M25 J11 anti-clockwise exit
- Direction
- Anticlockwise
- Lanes closed
- Carriageway closed
- Reason
- Road improvement or upgrading
- Schedule
- 23:00 Fri 2 Oct 2026 → 05:00 Mon 5 Oct 2026
+ 2 more near Junction 12 - see all the M25 traffic news →
This is the news for Junction 12 only, not the whole M25. For the rest of the motorway see all the latest M25 traffic news, the overhead signs and the speed limits in force now.
Updated 02:57 Sat 3 Oct 2026