Drivers lost almost £60 million last year by failing to appeal against unfair parking tickets, according to a survey.
In 2010, around 5% of motorists in the UK received a parking ticket where they had grounds for appeal, paying out an estimated £58.5 million, the poll by car insurer LV= found.
Of these, only 22% bothered to contest the ticket but of those who did, 88% were successful in their claim.
More than half (53%) who chose not to appeal said they assumed they would lose, while 8% did not know how to initiate a claim.
The poll of 2,003 adults, including 1,728 drivers, showed that the majority of unfair parking fines are issued in areas were parking signage is unclear.
A total of 2% of drivers said parking attendants had fabricated evidence to support the issuing of a ticket.
Nearly half (49%) of tickets issued unfairly are given out on public roads, while 10% are issued in car parks of public buildings managed by local councils, including libraries, hospitals and doctors' surgeries.
Also, 182,000 tickets issued unfairly last year came from unregulated private parking operators.
As many as 10% of motorists given an unfair ticket on privately-owned land said they had been threatened with court proceedings or debt recovery action if they did not pay up.
The average cost paid by motorists given a ticket in unfair circumstances was £42.