Matthew Stockdale claims he was repeatedly cut up and shunted three times by the other motorist.
He said he made six 999 calls and was connected to three police forces.
Northamptonshire Police, which took the first call, has apologised for the communication failures, saying it plans to interview the lorry driver.
The force says it is carrying out a "live investigation", but no arrests have yet been made. Bedfordshire Police is due to interview Mr Stockdale.
Dashcam footage of the encounter, recorded on the M1 near Northampton on 11 November, shows the lorry hitting Mr Stockdale's car.
"I honestly thought I was going to die," he wrote in a police statement.
"My life literally rushed before my eyes. Whilst that sounds dramatic, I can honestly say I have never felt fear like it. I began shaking uncontrollably."
The former special constable said he was driving southbound towards his home in Northampton when a lorry began flashing him, sounding its horn and driving up to the rear of his car.
Footage shows the lorry apparently bashing his car as it passed at about 20:40 GMT, and repeating the action 14 minutes later.
Mr Stockdale then called 999 and was connected to Northamptonshire Police. After the second incident, he was connected to Thames Valley and then Bedfordshire Police.
Despite assurances from all three forces that help was on the way, he said no-one arrived.
Mr Stockdale, who runs a dashcam company, followed the lorry to a depot in Dunstable where an ambulance took him to hospital with neck and shoulder pain.
Bedfordshire Police had called the paramedics and one of its officers arrived at the hospital nearly three hours after the first call was made.
Footage shows Mr Stockdale stayed in the middle lane for some time, which motorists can be fined for, but he said he was about to move over when the lorry driver began to "intimidate" him.
The Northamptonshire force said it could not attend because officers trained to deal with such incidents were in pursuit of a stolen car. The force has seen the footage and an investigation is under way but no arrests have been made yet, a spokesman confirmed.
Supt Dennis Murray, who is in charge of the force's control room, said: "What we should have done was contact the other forces... that's a failure on our part, for which I apologise to the driver of that vehicle."
The lorry driver, who lives in Bedfordshire, was employed by Wincanton hauliers through an agency. A spokesman confirmed he is "no longer conducting deliveries".
Liability for the car damage has been accepted by the firm's insurers.
A driver who says he was "deliberately and repeatedly rammed" by a lorry has criticised police for failing to respond to his calls for three hours.