Just before 2am, emergency services were called to the Hume Highway near Rock Lodge Road, Lade Vale, after reports a Mazda 6 and a Pantec truck had collided head-on.

Police inquiries suggest that after the initial collision between the two vehicles, a passenger in the Mazda got out and was struck by a second truck, travelling northbound.

The man, aged in his 20s, died at the scene. He is yet to be formally identified.

The Mazda driver, a 23-year-old man, was treated at the scene before being airlifted to Canberra Hospital in a critical condition.

The two truck drivers, aged 32 and 65, were uninjured and taken to Yass Hospital for mandatory testing.

A crime scene was established, which will be examined by specialist police from the Crash Investigation Unit alongside an investigation into the circumstances surrounding the crash.

Northbound lanes of the Hume Highway are closed, and local traffic diversions are in place.

Just before 9am, the Live Traffic website reported that northbound traffic was still affected, with both northbound lanes closed and motorists using the rest area to pass the incident site.

Emergency services and Transport for NSW crews were still on scene.

Travellers are advised to expect delays, reduce speed and exercise caution in the area.

Check livetraffic.com for the latest information on the traffic conditions.

Anyone with information about the incident should contact Crime Stoppers on 1800 333 000 or https://nsw.crimestoppers.com.au.

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