North Circular crash shuts A406 for seven hours near Brent Cross
Drivers diverted after collision at Chiswick Roundabout on 20 August 2026
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A collision on the North Circular Road near Brent Cross closed both carriageways for seven hours on 20 August 2026. The incident occurred at Chiswick Roundabout, where the A406 meets the A41. Police confirmed the closure began at 08:30 and the road did not reopen until 15:30.
Transport for London, which manages the North Circular, set up diversions along local routes in Brent, Hendon and Golders Green. Drivers reported long queues on the A5 Edgware Road and A1 Great North Road. The Metropolitan Police directed traffic at key junctions, including Brent Street and Finchley Road.
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Emergency response and delays
London Ambulance Service and London Fire Brigade attended the scene. A spokesperson for the Metropolitan Police told *This Is Local London* that officers were investigating the cause of the collision. No details of injuries or the number of vehicles involved have been released.
Transport for London advised drivers to check its traffic news website before travelling. A spokesperson said: "We are working with emergency services to reopen the road as soon as it is safe to do so." The closure coincided with the morning peak, extending delays into the afternoon.
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What happens next
The Metropolitan Police said its investigation into the collision is ongoing. No arrests have been reported. Transport for London has not announced any plans to review road safety measures at Chiswick Roundabout. Drivers are advised to allow extra time for journeys in the area while residual delays clear.
Questions this report answers
+How long was the North Circular closed after the crash?
The North Circular Road at Chiswick Roundabout was closed for seven hours on 20 August 2026. The closure began at 08:30 and the road reopened at 15:30, affecting morning and afternoon traffic in north-west London.
+Which areas were most affected by the diversion?
Traffic was diverted through Brent Cross, Hendon and Golders Green. Long queues formed on the A5 Edgware Road and A1 Great North Road, with delays reported at Brent Street and Finchley Road junctions.
+Were there any injuries in the crash?
Emergency services attended the scene, but the Metropolitan Police and London Ambulance Service have not released details of injuries or the number of vehicles involved in the collision on 20 August 2026.
+What should drivers do now the road has reopened?
Transport for London advised drivers to expect residual delays and check its traffic news website before travelling. The Metropolitan Police is investigating the collision, but no further road closures have been announced.
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