Latest trends suggest councils in England could be set for a £1bn parking income by the end of the decade.
Research suggests councils expect to make a record surplus of £885m from parking fees in 2018-2019, with some areas doubling charges.
Previous analysis by the RAC Foundation found the combined surplus made by English councils in 2017-18 was £867m, compared to £658m in 2013-14.
Steve Gooding, director of the RAC Foundation, said: 'Official data shows councils in England have consistently under-estimated how much surplus they will make from their parking operations and on that basis they appear collectively to be on track to hit a £1bn profit in the coming financial year.
'Parking charges are there to manage traffic, not raise revenue, with any money left over after costs ring fenced for spending on transport, including extra parking provision.
'With sums this large in play, the question must be whether they are actually helping our town centres and high streets to thrive, or whether it feels more like motorists being targeted to help increasingly cash-strapped councils balance their books.'
Cllr Martin Tett, transport spokesman for the Local Government Association, said: ‘Councils have to strike a balance when setting parking policy, both on street and off street, to make sure that there are spaces available for residents, high streets are kept vibrant and traffic is kept moving.
‘Any income raised through on-street parking charges is spent on running parking services and any surplus is only spent on essential transport projects, such as tackling our national £9bn roads repair backlog and other transport projects that benefit high streets and local economies.’