A crash involving five heavy goods vehicles has led to delays on the A55 and the temporary closure of A483 Chester to Wrexham road.
One driver was cut free and airlifted to hospital in Liverpool where he is critically ill.
The crash happened between the Posthouse roundabout and Rossett junction of the A483 Wrexham bypass at 0719 GMT.
By mid-afternoon 20 minutes delays were reported as recovery work continued.
Diversions were put in place as emergency services dealt with the incident which led to the closure of the Wrexham bound section of the dual carriageway between Belgrave roundabout and Rossett.
It then caused traffic delays on the adjoining A55 near the Chester business park turn-off with reports traffic has backed up towards the M53.
The National Traffice Control Centre said motorists affected by mid afternoon were those travelling between Chester and Wrexham.
Both sides of the carriageway remain closed, and there are roadworks and temporary traffic lights on the diversion route in Rossett.