The video shows Carragher aiming a mouthful of spit at from the window of his auto into another vehicle driving alongside him, from which the teenage fan's father had been ribbing the Sky Sports pundit over his former side's 2-1 defeat at Anfield.
The incident took place after the game on Saturday and Carragher spat at the man and his 14-year-old daughter, who was also in the auto.
He said it was "totally out of order", adding that he'd apologised to the girl's family.
"I was goaded three/four times along the motorway while being being filmed and lost my rag". I thought it was a Liverpool fan at first wanting an autograph at first so I stopped.
Carragher was caught on camera as he pulled over to spit on the fan and his daughter.
Sky Sports have now responded to the incident, a spokesperson said:"It's unacceptable behaviour and we will be addressing it with Jamie".
In the footage, shot by the girl's dad, it begins with him goading the footie pundit by chanting "2-1, 2-1" and shouting "unlucky Jamie lad".
Carragher is now facing a fight to keep his job at Sky Sports, who will hold talks about the incident this afternoon.
When Carragher was a Sportsmail columnist, he wrote a column in March 2015 recounting an incident in which he was spat at during his playing career - but he insisted it was not worse than having his leg broken.
The report states that Carragher called the fan and his daughter to say, "I just want to apologise and I hope you are OK". I lost my head.
"She was crying. She said, 'I'm embarrassed, he has just spat in my face".
I was shocked more than angry when he did it because I couldn't believe what had happened'.