Stuart Mackenzie was four times over the limit when he ignored nine warning lights before crashing into five cars at temporary traffic lights.
A 16-year-old girl in one car suffered brain injuries in the collision on the A90 Dundee to Perth road.
Driver Max Stobbs, 19, also suffered serious head injuries.
Perth Sheriff Court heard how Mackenzie, or Airdrie, North Lanarkshire, had been drunk the night before the crash.
He then had more alcohol before getting behind the wheel of his work's van on 20 February last year.
Sheriff Gillian Wade told Mackenzie: "You deliberately decided to consume a significant quantity of alcohol which impaired your ability to drive.
"You failed to observe the reductions in the speed limit and failed to observe warning signs ahead of you, and you failed to observe the vehicles which had seen the warnings and stopped.
"You caused multiple injury and there is no alternative to custody."
Fiscal depute Carol Whyte told the court roadworks were being carried out on the dual carriageway and there was a convoy system in force.
She said: "Vehicles travelling east were slowed in a gradual manner from 70mph to a complete stop at a traffic light. In total there were nine different road signs advising of this, starting a mile prior to the red light.
"At 10.55pm four vehicles were stopped at the red light waiting for the convoy and the accused was seen to drive towards them. It appeared he had failed to notice the line of vehicles."
Mackenzie slammed into the back car in the line, trapping the two occupants, and causing it to hit three other cars "in a domino effect".
The court was told that his official alcohol reading was more than double the limit when taken five hours after the crash, but that he had been more than four times the limit at the time of the incident.
Solicitor David Holmes, defending, said his client expressed "genuine remorse" for those who had been affected by the crash.
Mackenzie admitted failing to reduce his speed and causing a five-car accident. He was also banned from driving for five years.
A drunk driver who left two teenagers with serious head injuries after smashing into a line of traffic has been jailed for two years.