For the second day running, motorway drivers have been delayed at the busy South Mimms junction, apparently because of a traffic light problem.

Several drivers have complained on Twitter about delays at or near the A1(M)/M25 junction, and queues have been reported on the A1(M) southbound carriageway back to Hatfield.

Highways England has warned drivers to be careful in the fog, which according to the Met Office could effect the evening rush hour and persist until tomorrow morning.