M25 delays could last hours after van crash in Hertfordshire

Herts Police were called to the anticlockwise carriageway, near junction 18 (Chorleywood interchange), at around 10.35am today (May 20) following the smash. The van was the only vehicle involved. Traffic has now been released on the #M25 anti-clockwise between J19 (#Watford) and J18 (#Rickmansworth).

Please note, the J18 anti-clockwise exit slip road remains closed whilst emergency services remain in attendance. pic.twitter.com/evHi1RPyS4

-- National Highways: East (@HighwaysEAST) May 20, 2025

"Emergency services are at the scene," a police spokesperson said. "Road closures are in place and motorists are advised to seek an alternative route." It was initially confirmed that the exit-slip was blocked, before National Highways shared that all anticlockwise traffic had been stopped.

Motorway traffic has now been released, while the slip road remains shut, but knock-on queues back to the M1 and half-hour delays anticlockwise remain.

There are more minor delays travelling clockwise.

Emergency services are continuing to work at the scene as of 12.04pm, with Google Maps warning of delays potentially lasting up to the evening rush hour.