Car being driven by a mum-of-two who worked in Bletchley was involved in a triple fatal crash and could have been travelling at around 102mph when it collided with a stationary lorry.
Driver Genevieve Reason, who was killed along with two teenagers, had small traces of alcohol and amphetamines in her system, an inquest heard.
Ms Reason, who was 32 and lived in Woburn Sands, suffered multiple injuries and died instantly.
She worked as a front of house manager at Formula Fast Karting based on Bond Avenue, Bletchley.
Also killed were her passengers, Lewis cook and Mary-Anne Wykes, who were both 16 and lived in Bedfordshire.
Witnesses told the inquest they saw the car catch fire after it crashed into the back of a lorry on the old A421 at Lidlington in May last year.
Road worker Lee Osborne saw the Scania lorry stationary on the wrong side of the road but “lit up like a Christmas tree,” he said.
“I saw a car approaching, in the time it took me to travel up the hill the car had passed me at speed,” he said.
“As the car passed me it I saw it go straight into the lorry and heard a bang.
“I felt sick to my stomach. I do not recall seeing any brake lights.”
Witnesses said the car was travelling at between 80-120mph but would have had plenty of room to pass the lorry
Lorry driver Mark Griffin said he was completing a legal u-turn at Sheep Tick End before resting up for the night when he saw Ms Reason’s Audi heading towards him.
The force of the collision meant he could not escape through the driver’s side and had escape through the passenger side door.
Two passengers escaped but the remaining three were trapped.
PC Ian Marsters said Ms Reason had picked up passengers in Marston Moretaine to head to a party in Woburn Sands. He said the driver “failed to react correctly to the lit Scania and that excessive speed, alcohol and drugs were the causes of the collision.”
Recording a verdict of deaths by road collision, assistant Beds coroner Ian Pears said Ms Reason was driving too fast and misjudged the lorry in her path.
She had a ‘recreational’ amount of amphetamines in her system and was not over the driving limit for alcohol,” he said.