West Midlands PC Zaid Malik was off duty when he got into an argument with another driver in Birmingham.
He convinced friend Roger Baker, 50, to provide a false alibi. Both denied a charge of conspiracy to pervert the course of justice.
Malik, 51, of Sparkhill and Baker, 50, of Acocks Green, were jailed for 21 months and 12 months respectively.
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West Midlands Police said the incident took place in Stechford on 26 February 2015.
The force said witnesses accused the former Coventry-based PC of being the aggressor, but police decided not to press charges when a seemingly independent account from Baker backed Malik's claim he was the innocent party.
Police said investigators became suspicious after revealing inconsistencies in the men's statements. They discovered the two were friends and Baker, of Westfield Road, had not been at the scene of the dispute.
Both men were found guilty following a trial and sentenced on Tuesday at Birmingham Crown Court.
Malik, of Durham Road, continued to work for West Midlands Police in a role outside the evidential chain up to his court appearance.
The force said a special case hearing would be held with Chief Constable Dave Thompson to determine his future.
Ch Insp Brian Carmichael, from the Professional Standards Department, said: "We demand the highest standards from all our officers. The public should expect to be treated fairly and respectfully."

The drone - dubbed Aquila -  flew for one hour and 46 minutes in Arizona.
On Aquila's maiden voyage last summer, the autopilot system was confused by heavy wind and crash-landed.
This time, the drone flew at an altitude of 3,000ft, a long way from Facebook's intended 60,000ft goal.
The social network has ambitious plans for its drone fleet and eventually wants to have them communicating with each other via lasers and staying in the air for months at a time.
The test - which took place in May but is only now being made public - went "perfectly", according to a blog post detailing the flight.
Facebook had initially heralded its June 2016 test a success but later admitted the drone had crashed on landing.
The crash was only revealed when it emerged that it had been investigated by the National Transportation Safety Board.
This time, the engineering team added "spoilers" to the wings to increase drag and reduce lift during landing. They also modified the autopilot software and applied a smoother finish to the craft.
The team filmed the landing and included the video in the blog post.
Director of aeronautical platforms Martin Luis Gomez said the drone had suffered "a few minor, easily repairable dings".
Aquila - which has a wingspan of a Boeing 737 - is part of Facebook's ambitious plans to connect the world to the internet.
This week, it announced that it has two billion users, more than a quarter of the world's population.
A police officer has been jailed for lying about his part in a road rage row.
[NEXT_CONCEPT]
Facebook has completed a second test of a solar-powered drone designed to bring internet access to remote parts of the world.