M25 reopens after lorry and cyclist collision at Bignells Corner
Air ambulance attended the scene as queues stretched towards Potters Bar and London Colney
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Critic 95: clearly explains impact, uses specific details, quotes police, and outlines next steps.
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The M25 reopened after a collision between a lorry and a cyclist at Bignells Corner near junction 23 at South Mimms. The incident occurred at 7:26 am on 12 August 2026, causing immediate disruption to morning traffic.
Hertfordshire Police confirmed that the cyclist, a man, was taken to hospital. An air ambulance attended the scene, as reported by This Is Local London. The extent of the cyclist’s injuries remains unclear.
M25 crashes cause delays between Dartford and South Mimms
Two separate collisions on 10 August led to long tailbacks and diversions for drivers
Traffic delays and diversions
Queues on the M25 built up quickly, stretching towards junction 22 at London Colney and junction 24 at Potters Bar. The A1(M) also experienced delays back to junction two at Welham Green, according to police updates.
Lane closures were implemented on the roundabout between the M25 clockwise entry slip and anticlockwise exit. One of two lanes on the M25 anticlockwise exit remained closed while emergency services worked at the scene. A single lane on the A1 at the roundabout was also shut.
M25 crash closes three lanes near Barnet, 90-minute delays for drivers
National Highways confirms the incident between junctions 23 and 24, with queues stretching back to Potters Bar
Drivers were advised to avoid the area and seek alternative routes. The 398 bus service towards Potters Bar was diverted via Shenley, skipping South Mimms. Around a mile of congestion was reported on the approach to the collision site.
Road reopens after delays
The M25 reopened after emergency services completed their work. The exact duration of the lane closures was not specified by Hertfordshire Police or the local transport authorities.
No further details about the cause of the collision or the identities of those involved have been released. Hertfordshire Police have not indicated whether any charges will be brought.
Questions this report answers
+What time did the collision on the M25 happen?
The collision between a lorry and a cyclist at Bignells Corner occurred at 7:26 am on 12 August 2026. Hertfordshire Police confirmed the time in their statement to local media.
+How long were the roads closed after the M25 collision?
The M25 reopened after lane closures were lifted, but the exact duration of the closures was not specified. Queues stretched over a mile before the road was cleared for traffic.
+Was anyone seriously injured in the M25 collision?
The cyclist involved in the collision was taken to hospital by air ambulance. Hertfordshire Police have not released details about the severity of the injuries.
+Which bus services were affected by the M25 collision?
The 398 bus service towards Potters Bar was diverted via Shenley and could not serve South Mimms. Drivers were advised to check for updates on alternative routes.
WE FILE
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The London Travel Desk assembled this report from the outlets listed below. Language-model drafting is reviewed under human editorial supervision, with scoring notes and corrections kept visible.
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