Tasmania Police said the Launceston man in his early 20s was killed when his Holden Commodore ute crashed head on into a Toll semi-trailer.

The vehicles erupted in flames on impact.

The truck driver, aged 45 and also from Launceston, was taken to the Launceston General Hospital.

Police could not confirm the condition of the man last night.

The man in the ute was travelling west on the Bass Highway at Christmas Hills when police say it appeared he crossed to the wrong side of the road and collided with the truck.

The truck veered off the side of road after the impact and ploughed into trees where the truck hit a 30-centimetre diameter tree.

Police said the truck driver was lucky to be alive.

The ute driver's next of kin last night had yet to be notified of his death.

Tasmania Police attended the scene at 5pm yesterday.

The highway was blocked at Bengeo Road and the east-bound road was blocked at the slip lane into Deloraine on the highway.

There were police vehicles at the corner of Mole Creek Road and Emu Bay Road redirecting traffic around the incident.

Police earlier advised motorists to avoid the area.