Motorists travelling on one of the busiest sections of the M25 are facing long delays this morning after a crash at the Swanley Interchange partially blocked the A20. The collision happened on the roundabout that links the M25 with the M20, and drivers have been warned to expect hold-ups of around half an hour.
Congestion built up quickly on the approaches to the junction. Queues on the M25 stretched back towards Dartford, while London-bound traffic on the M20 was left crawling for miles through Kent as vehicles funnelled towards the partly blocked roundabout.
Part of the A20 remains shut at the interchange while the scene is dealt with. Drivers heading into south-east London are being urged to allow plenty of extra time and to check the latest conditions before setting off.
The Swanley Interchange is one of the most important junctions on the London orbital motorway, where the M25 meets the M20 and the A20 in north-west Kent. It sits just south of the Dartford Crossing and serves as a major gateway for traffic moving between London, the Kent coast and the Channel ports.
Thanks to its position, the junction carries a heavy blend of commuter traffic, freight and long-distance travellers throughout the day. It is routinely busy during the morning peak, and even a minor incident can send queues spilling back along both the M25 and the M20 within minutes.
The M25 is among the busiest motorways in Europe, with the stretches around Dartford and Swanley regularly carrying well over 150,000 vehicles a day. Breakdowns, roadworks and collisions are a frequent source of delays here, and the section between the Dartford Crossing and the M20 turn-off is regarded as one of the most congested on the whole orbital.
The interchange itself is a large roundabout woven around the motorway slip roads, with the A20 running through it on its route between London and Dover. That makes it a critical link for anyone travelling to and from the capital’s south-eastern suburbs, as well as for lorries heading to and from the Channel Tunnel and the Port of Dover.
Disruption here tends to ripple outwards. Traffic bound for central London can back up along the M20 deep into Kent, while drivers approaching on the M25 from Surrey and the south can also find themselves caught in the tailbacks. With the Dartford Crossing nearby, delays at Swanley often add to the pressure on one of the country’s busiest river crossings.
Anyone planning to travel through the area is advised to check live traffic information before leaving and to build extra time into their journey. Those who can be flexible may want to delay setting off until the scene has been cleared and the road fully reopened.
Drivers already approaching the junction should stay in lane, keep a safe distance from the vehicle in front and be ready for sudden slowdowns. Overhead gantry signs and traffic updates can help you judge whether to press on or divert onto another route.
Possible alternatives into south-east London include the A2 corridor or routes via the Blackwall Tunnel, although these roads are also likely to be busier than usual while the disruption lasts. For commuters who can switch, public transport may be the more predictable option this morning. TfL is also consulting on a Superloop extension for Wood Wharf.
We will keep this live blog updated as the situation develops, including when lanes reopen and the queues begin to ease.
Traffic officers and recovery crews will work to clear the carriageway as quickly as possible, but drivers should not expect conditions to return to normal straight away. Even after the road fully reopens, it can take an hour or more for the residual queues to clear, particularly during the morning rush.
