One person has been critically injured after a crash on State Highway 16 in rural northwest Auckland.

Police said emergency services were called to the single-car crash on the Kaipara Coast Highway near Tauhoa at 12.13pm.

The driver, the car’s only occupant, was taken to hospital in a critical condition, police said.

The crash has closed SH16 and diversions are in place.

Police asked motorists to avoid the area or expect delays.

The NZ Transport Agency said the crash happened near Boler Rd. SH16 was closed between Tauhoa and Wharehine Rds, the agency said.