A man threatened two men with a knife after walking in the middle of a Wisbech road and forcing their car to swerve around him.
Benjamin Hammond, 23, was walking in Market Place on the afternoon of February 2 when the victims approached in a Seat Leon.
As they narrowly avoided him, Hammond slapped the car windscreen, shouted and swore and then opened the passenger door and pulled a small knife on the passenger, a man in his 30s.
Realising he wasn’t speaking to the driver, he went and confronted the other man, also in his 30s, who had already got out of the car.
He took the car keys and threw them away further along the road but then picked them up and offered to give them back in exchange for an apology.
The driver refused but Hammond handed them over anyway before making off.
Hammond, of Mill Close, Wisbech, was arrested and admitted being involved but denied having the knife.
However, he was found guilty of making threats with a knife in a public place following a trial at Cambridge Crown Court earlier this month and on Friday 20 July he was jailed for 18 months at Peterborough Crown Court.
He received 16 month sentences for both offences, to run concurrently, and a further two months for breaching a suspended sentence for an offence of grievous bodily harm.
DC Simon Rust, who investigated, said: “The victims in this case feared for their safety and were understandably shaken.
“We take all knife crime seriously. It can have devastating consequences and the sentence given today should act as a deterrent to others carrying weapons.”