Adrian Moir, spotted the accident down an embankment of the southbound carriageway just after junction 33 at around midnight on Wednesday, February 21.
The 47 year-old has described how his training kicked in as he daringly scrambled into action to set about freeing the injured man. The HGV driver from Bedfordshire said: "I was a passenger in a car driving down the M6 with my work colleague and I saw this light shining out from the embankment.
"I'm an ex-police officer and I just thought, that's not right. I looked again and saw a car down there and it was smoking.
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"By the time we managed to stop safely we were about 200 metres along the hard shoulder.
"I dialled 999 and requested all three of the emergency services.
"I asked if it was ok for me to go and help the driver and the handler said yes.
"I went to the scene with my colleague and saw a HGV driver had already stopped and gone down.
"He shouted up to me, there's one person in the vehicle and he's still alive. We then scrambled down the embankment and tried to get into the car.
"I picked up a large piece of concrete and tried smashing the windows but it just bounced off. I managed to get in using a piece of signage that had broken in the accident.
"We got him out of the car and dragged him up the embankment and put him in the recovery position.
"He was in complete shock. He was very upset and didn't seem to realise what had happened.
"I asked him how old he was, he said he was 49. I said, 'mate you're going to see your fiftieth birthday - you're the luckiest man alive'."
Fire, police and ambulance services arrived at the scene shortly after.
Four fire engines from Lancaster, Garstang and Fulwood were called out to the incident.
A spokesman for the fire service said: "The car left the road and crashed into a tree down an embankment.
"This was a high speed accident and the man had an extremely lucky escape."
The man was taken to hospital with what were believed to be non-life threatening injuries.
Crews remained at the scene for around 40 minutes.