The campaigners say vulnerable people are housed in HMOs and they attract anti-social behaviour.
Henri Nikolli, 19, from Welwyn Garden City, is jailed for multiple drugs and firearms offences.
The cast say they made friends for life during the filming of the new BBC One series.
Specialist contractors are sent to the scene to clear a "significant oil spillage".
Passengers are being advised to check before they travel as major engineering work takes place.
National Highways says there are delays of up to 30 minutes in the area.
All lanes are reopened at about 07:00 BST
A non-league club hopes to reach League Two by 2034 - despite having only been founded in 2023.
National Highways is urging drivers to be patient while efforts are made to deal with the incident.
