English councils generated £819m from parking fees and fines in 2016-17, an increase of 10% on the previous year, a study has suggested.
This figure represents income from parking charges and penalty notices with running costs deducted.
The RAC Foundation, which carried out the research, said motorists should ask how their council spends the cash.
The Local Government Association said parking charge surpluses were spent on "essential transport projects".
Income collected by the 353 English local authorities was up 6% and costs rose 2% compared with 2015-16, when the surplus was £744m.
Many of the highest totals were seen in London, with the largest in Westminster, which had a surplus of £73.2m.
Outside the capital, big surpluses were recorded in Brighton and Hove, Milton Keynes and Birmingham.
RAC Foundation director Steve Gooding said the rise in profits reflects the "record number of cars and volume of traffic".
"We welcome the fact that councils are increasingly investing in technology to help make parking easier and less stressful," he added.
Westminster Council has created an app to direct drivers to free parking spaces.
Martin Tett, the Local Government Association's transport spokesman, said parking charges keep the roads clear, help pedestrians, motorists and cyclists safe and enable people to park near their homes.
They also go towards tackling the UK's £12bn roads repair backlog, he added.
An annual report from the Asphalt Industry Alliance this year found that almost a fifth of roads in England and Wales were in "poor" condition.
Councils were almost £730m short of what was needed to keep the road network in "reasonable order", it said.
Top 10 councils in England with the largest parking operations surplus:
- Westminster £73.2m
- Kensington and Chelsea £32.1m
- Camden £26.8 m
- Hammersmith and Fulham £23.1m
- Brighton and Hove £21.2m
- Wandsworth £20.5m
- Islington £19.1 m
- Haringey £14.6m
- Hackney £14.5m
- Hounslow £12.0m
Source: the RAC Foundation