Police were called to reports of a traffic incident involving one vehicle on the northbound side of the A19 near Hartlepool at about 2:40pm today (Thursday).
The northbound carriageway has been closed at the A179 junction to allow access for the Great North Air Ambulance.
The male driver has been taken to Hartlepool General Hospital with serious injuries.
Motorists are advised to avoid the area and find an alternative route.
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