SMOKE could be seen from kilometres away as a truck was engulfed in flames on the Capricorn Hwy late Wednesday afternoon.
Emerald police were called to the site about 20km east of Emerald shortly after 5pm after reports a B-double towing two trailers of machinery had caught fire.
Blackwater police was the first of emergency crews on the scene as Emerald police, QFRS and QAS arrived shortly after to find the truck well ablaze.
Officer-in-charge Snr Sgt Peter McFarlane said the fire appeared to have started in the engine area.
Initial reports indicated the 56-year-old truck driver was alerted to the fire by a passing motorist who used a CB radio to contact him.
The truck driver pulled the B-double over to a safe place on the side of the road and was able to retreat to a safe distance from the blaze which caused a small grass fire nearby.
The highway was cut while the fire was being extinguished and had to be deemed safe by RoadTek personnel.
Blackwater residents Kurt Newman and Jesse Beak were heading home with a busload of apprentices following a day at Emerald's TAFE campus and were delayed by the fire.
"We were here before emergency services… As we approached we could see a big black cloud of smoke in the air," Mr Beak said.
"It was raging by the time we got out there."
Mr Newman said the truck driver had exited the cab and rushed east along the highway, away from the flames.
"Stuff kept blowing up - there were tyres and other things on the truck exploding," Mr Newman said.
Police are treating the fire as non-suspicious.