A “significant defect” has been fixed on the A1(M) in Hertfordshire, says National Highways. The northbound stretch of the road between the Welwyn and Stevenage junctions reopened at about 06:00 GMT on Saturday after being closed since 21:00 on Thursday for repairs.

The 5m (16ft) dip was identified after 45 core-probe tests were carried out and a design solution organised to fill the 4m-wide (13ft) void and to resurface the road.

The road was now open “following the works to repair the road due to a significant defect”, it said on social media.

(Picture – National Highways)