Police are investigating the death of a person after a light truck struck a barrier on the entrance to the North-Western Motorway at Te Atatu Peninsula. Credit NZPA/Bradley Ambrose

A truck driver is dead after his vehicle crashed through a safety barrier on Auckland's north western motorway today.

Police said that the accident happened near Te Atatu about 7.30am but details of the victim were not yet known.

Motorists heading into Auckland City from the west were warned they could face long delays as police closed a motorway on-ramp and off-ramp to clear the site.