Highways England has closed a northbound section of the A1 near Newcastle and Gateshead after a hole appeared in the carriageway on Saturday (25 June).
By Monday morning the Government-owned company had put a contraflow in place on the southbound carriageway as it carried out repairs.
The hole was at least 3m deep and around 6.5m diameter
Highways England said the northbound carriageway would remain closed between junctions 67 and 68 until Wednesay (29 June), causing disruption. The road carries an average 90,000 vehicles a day.
Rob Beckitt, duty operations manager at Highways England said: ‘Safety is our top priority; we have to ensure the carriageway is totally safe before drivers use it.’
Highways England said the hole was at least 3m deep and around 6.5m diameter and was believed to be related to old mine workings.
The hole was filled with specialist concrete
By Monday afternoon, the hole had been filled with a specialist concrete mixture and Highways England contractors had begun to drill holes to pump more material underneath the repair to prevent a repeat collapse.
Other measures put in place to minimise disruption include lifting toll barriers for the Tyne Tunnel and suspending roadworks on routes that are likely to be affected by diverted traffic.
Highways England said there would be extra traffic officer patrols and recovery vehicles on standby to quickly remove any breakdowns in the contraflow.
The hole was discovered by Highways England when a slight dip in the road surface became apparent. Workers then cut around the dip to investigate and discovered a large void underneath the road surface.
It was in a coned-off stretch of the A1, so there was no traffic using the road at the time.