When Thomson then got out of the car, which he had taken without the owner’s consent, public-spirited James Staley took the keys from him before waiting for the police to arrive.
Thomson (29) of Lythalls Lane, Holbrooks, Coventry, was jailed for a total of 20 months by a judge at Warwick Crown Court who also banned him from driving for four years.
He had pleaded guilty to charges of aggravated vehicle taking, driving with excess alcohol, having no insurance and driving while disqualified.
Prosecutor Delroy Henry said that at 5.30pm on June 18 Mr Staley saw Thomson driving a black Vauxhall Astra in a dangerous manner along a number of road.
Such was his concern that he called the police and then gave them a commentary as he followed the Astra on a ten-minute journey over several miles along a series of roads.
Thomson was driving at speed, skidding round corners, and went the wrong way round a roundabout, hitting a parked car before continuing on his way.
In Belgrave Road he rammed a car in front of him in which a couple were travelling with their two young children, as a result of which the mother needed treatment for a neck injury.
He then went onto the wrong side of the road to get past a line of queuing traffic and then drove through a series of red traffic lights, said Mr Henry.
Eventually Thomson stopped in Luscombe Road, and Mr Staley also pulled over and informed the police where they were.
“Such was his concern that when the defendant came to a stop and got out of the Astra, it was Mr Staley who took his keys from him pending the arrival of the police.”
When Thomson, who was ‘somewhat aggressive’ when the police arrived, was breath-tested he was found to be almost three times the legal alcohol limit.
And Mr Henry pointed out that Thomson had a conviction in 2013 for excess alcohol and convictions in 2011 and last year for failing to provide a specimen of breath for analysis.
David Jackson, defending, said Thomson, who has written a letter for the family in the car he rammed, had been remanded in custody for eight weeks.
Arguing that he could be given a suspended sentence, Mr Jackson said: “He is of course realistic about his position, and he expresses genuine remorse.
“This is the first time he has been responsible for such a bad piece of driving, even though his record for driving is appalling.
“He has realised this is a significant escalation in his offending, and he has sought to address the drinking which is the root of his problems.”
He pointed out that Thomson, who was driving a friend’s car he had taken without permission, had stopped of his own accord, rather than crashing or being forced to stop.
But jailing him, Judge Sylvia de Bertodano told Thomson: “You had had a great deal to drink and you were driving a car you had taken from a friend through Coventry.
“At that busy time of day you drove for a number of miles for a period of ten minutes, and so concerned was another driver that he followed you and described your driving to the police.
“When you drive like this you can kill someone; and week after week I am dealing with a grieving family in the public gallery because of someone driving in the way you did.
“It was pure good fortune that no-one was killed or injured. Of course, no-one was injured, but that was not down to you; it was pure good luck.
“The message must go out to others that if you get drunk and drive dangerously and cause damage, you must go to prison.”