Councils are making huge profits from parking charges while cutting road safety spending, according to new figures.
Councils in England took more than £411m in parking charges in 2011/12 - an increase of almost 15% on 2010/11, the Institute of Advanced Motorists (IAM) said.
Yet at the same time, the amount spent by councils on road safety, education and safe routes to schools, decreased by 18% to £105m, the IAM said.
It added that overall revenue spending on highways and transport reduced by 6% between 2010/11 and 2011/12, while capital expenditure (on construction, tarmac etc) reduced by an estimated 13%.
Peter Box, a councillor and chairman of the Local Government Association's economy and transport board, said: "With the number of cars on our roads increasing, it's more crucial than ever that parking is properly managed.
"Councils spend billions of pounds a year on transport services and are currently facing general budget cuts of up to 33% and a £442m reduction in their highways maintenance budget.
"This means they have far less to spend on roads and transport initiatives."
Local Government Minister Brandon Lewis said: "The analysis by the Institute is wrong.
"Income from on-street and off-street parking only rose by 3.7% in the last year, which is lower than the prevailing rate of inflation.
"The Institute have failed to adjust for the fact that councils have cut costs through efficiency savings."
Westminster Council said the £37.1m surplus was all spent transport improvements in 2011-12 .
"Even if these figures were right, which they are not, Westminster’s parking surplus is spent entirely on improving roads, transport and infrastructure – for motorists that this group claims to represent," Cllr Daniel Astaire said.
"Westminster must manage the kerb space properly so that it is accessible to residents, visitors and businesses, all of whom have competing needs to park in one of the busiest cities in the world."
The IAM said the top council "earners" from parking in 2011/12, all in London, were:
:: Westminster - up 8.7% from 2010/11 to £38m
:: Kensington and Chelsea - up 31% to £27.5m
:: Camden - up 18% to £25m
Outside London the biggest earners were:
:: Brighton and Hove - up 18.9% to £13.7m
:: Milton Keynes, Buckinghamshire - up 9.3% to £6.5m
:: Newcastle upon Tyne - up 51% to £6.2m