All traffic has stopped both ways on the M1 since around 2.20pm today (January 13).
Motorists have been urged to avoid the area and find an alternative route as the incident is being dealt with.
The incident is causing miles of traffic and 30 minute delays in the area, according to National Highways.
#M1 between J4 (#Elstree) and J5 (#Watford) is closed in both directions due to @HertsPolice led incident.
More details to follow. pic.twitter.com/nWX69ffudU
— National Highways: East (@HighwaysEAST) January 13, 2025
It is unknown when all closures will be lifted.
A spokesperson for Hertfordshire Police said: “Police were called at 2.21pm today (Monday 13 January), following an incident on the M1.
“Police attended the scene, and closures have been put in place between junctions 5 and 6 (Watford and North Watford) in both directions to allow for enquiries to be carried out.
“Closures are also in place at Bucknalls Lane and diversions are in place.
“Motorists are urged to avoid the area and to seek an alternative route.”
