A family of four were travelling in their ute south along the Bruce Highway at Raglan, near Gladstone, about 11pm on Tuesday when they slowed down behind another car with a wide load.
A prime mover truck failed to slow down and crashed into the ute, forcing it into the back of the other car.
A 40-year-old mother and her 13-year-old son died at the scene.
The 42-year-old father and a 15-year-old boy were taken to Rockhampton Base Hospital with non-life-threatening injuries.
"This crash has torn one family apart and has traumatised numerous others," Acting Inspector Ben Wiltshire told reporters on Wednesday.
Two people in the third car suffered minor injuries.
The 30-year-old truck driver was charged with one count of dangerous operation of motor vehicle causing death or grievous bodily harm.
He will face Gladstone Magistrates Court on December 9.
The forensic crash unit is continuing to investigate.
The Bruce Highway is a notorious road for crashes with dozens so far this year, sparking the Queensland government to commit to getting it up to scratch.
"I just say that every time an incident like this happens on Bruce, it just it just sends regional communities into a real sense of despair, and our hopes and thoughts are with the families and with that community as well," Premier David Crisafulli told reporters.
"We have to do more on the Bruce and no one is suggesting that on a long road like that that you won't have incidents but we can do much better for Queenslanders who drive it."
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