Daniel Parr, 25, admitted he was driving his Megabus too fast on the M5 in Gloucestershire, killing 30-year-old Raymond Vaughan.
The early-morning crash just before Christmas 2010 caused a horrific pile-up involving a lorry, a coach and three cars.
Gloucester Crown Court heard that other motorists were so concerned about the fog and icy conditions on the morning of December 12 that they had slowed down to 40mph.
Yet Parr, who admitted he could see just 72ft (22m) ahead of him, was driving at 62mph – the maximum speed under law for his coach.
Because of the appalling weather Parr did not see the articulated Sainsbury’s delivery lorry travelling at 40mph in front of him on the northbound carriageway.
The court heard that he tried to take evasive action but clipped the rear of the truck causing it smash through the central reservation onto the southbound carriageway.
Mr Vaughan’s black Ford Fiesta, which was coming the other way, then collided with the lorry and a Rover ploughed into his car.
The married father-of-two, an engineer from Birmingham, died at the scene of the crash near junction 8 of the M5, between Strensham and Tewkesbury.
Prosecutor Martin Steen told the court: “This is a tragic case in every sense of the word.
“In short Parr was driving a Megabus on the northbound carriageway in thick fog.
“He came to collide with a Sainsbury’s lorry in front of him causing that lorry to smash through the central reservation and onto the southbound carriageway with the result that much-loved Raymond Vaughan died.”
Mr Steen said that passengers on the coach felt Parr was “in a hurry” by the way he threw their luggage on the coach as they boarded and how quickly he pulled away from the pick up.
“A passenger described the conditions as cold, foggy and icy. She heard a loud crash and a continuous scraping noise,” he said.
“The noise was horrendous and the windscreen shattered and fell all over her. She said afterwards the driver looked scared and shocked.
“Other witnesses on the motorway described the vehicle driving fast in the conditions given the fog.”
Mr Steen said that Parr told police he could only see the length of a cricket pitch in front of him – a distance of 72ft (22m).
Parr, who was taking the coach with a co-driver from Cardiff to Leeds, told officers: “The wagon just appeared in front of me. I didn’t know it was there. If there were fog lights they were very dim.
“The back of the coach must have caught the truck and after that I don’t really remember anything.”
The court also heard moving statements from Mr Vaughan’s wife and mother describing how their lives had been devastated by his death.
Julie Vaughan, his mother, said she and her two daughters, Patricia and Chloe, were already coping with the death of their father and her husband when Mr Vaughan died.
“Chloe told me that everyone she loves dies,” Mrs Vaughan said.
“Since my son’s death I have not slept a full night. I cry every single day for my son. The thought of him not being around to speak to or hold him is tearing me apart.
“My last image of him was going to see him in the mortuary.”
Mrs Vaughan added: “I do want to see justice but nothing will bring Raymond back and that’s all I want.”
Mr Vaughan’s wife, Hayley, said she had been left to care for their two children, one of whom was disabled.
“Raymond was the best dad and husband you could wish for,” she said.
“My children find it difficult to sleep and cry at night.
“I desperately miss my husband. He was my rock and I thought he would be with me for the rest of my life.”
At an earlier hearing, Parr, of Penallt Estate, Llanelly Hill, Abergavenny, Monmouthshire, admitted causing death by dangerous driving.
Robin Shellard, defending, said Parr, a coach driver for five years and of previous good character, was truly remorseful for what had happened and had written of his regret.
“The death of Mr Vaughan is something that has haunted him every day,” Mr Shellard said.
“It is quite clear that he was driving too fast for the conditions.”
Mr Shellard said that since the crash Parr, a father of two boys aged six and two, had changed from an outgoing person to someone who stayed at home and drank heavily.
“I hope Mr Vaughan’s family accepts that whatever Mr Parr has been through in the last 18 months is of course nothing to what Mr Vaughan’s family has been through,” he said.
“No sentence of imprisonment can bring Mr Vaughan back.
“He just hopes Mr Vaughan’s family can accept the feelings he has towards Mr Vaughan and the great regret he has.”
Judge Susan Evans QC jailed Parr for two years, banned him from driving for three years and ordered that he take an extended driving test.
She said: “This case is tragic in every sense of the word.
“On December 12 2010 you were the driver of a coach on the M5 in very difficult conditions early in the morning.
“You had a responsibility to your passengers and to other road users. As you said in your interview your visibility was less than 22 metres just before the collision.
“It was apparent from your passengers that some of them were concerned at the speed of your driving in the prevailing conditions.
“You were driving at the maximum speed of 62mph and a collision with another slower vehicle was inevitable.
“Your coach collided with the rear of the lorry and began a chain of events which neither you or the lorry driver could have prevented.
“It led to the tragic death of Mr Raymond Vaughan and the loss to his family has been immense.”
Judge Evans added: “I know what happened that day will have a profound effect upon you for the rest of your life and that you wish you could turn back the clock.
“This court has to send out a message to those that drive dangerously in icy conditions and that is what you did.
“Nothing this court can do can repair the damage done to Raymond Vaughan and his family.”