There are 138 types of fines for parking offences in NSW, ranging from $108 for parking longer than is allowed to $541 plus a demerit point for using a disabled parking space without a permit.

New York motorists face fines ranging from $US35 ($45.51) to $US180 ($234.71) for similar offences.

Fines for other offences in New York - parking longer than is allowed, stopping in a bike lane and stopping on a crossing - are also lower than in Sydney.

The cost of on-street parking in New York tends to be cheaper than Sydney, with fees of $US3.50 ($4.55) per hour in Manhattan and $US1 ($1.30) elsewhere in the city. On-street parking in central Sydney is $1.70-$7 per hour.

Motorists in London, Toronto and Hong Kong - cities with arguably better public transport than Sydney - also face lower parking fines. London drivers also receive a 50 per cent discount for early payment of a fine.

Parking fines in Victoria are lower than in NSW, ranging from $78 to $155, but the City of Melbourne collects more revenue from parking fines.

In the 2016 financial year, the council raised $41.57 million - compared to the City of Sydney's $30.5 million.

"Half of the net parking fine revenue, after deducting the costs of enforcing and processing the fines for the Sydney CBD and southern areas, is shared with the government," according to a council spokeswoman.

More than 1.2 million penalty notices for parking infringements with a total face value of $185.4 million were issued in NSW in 2015-16, according to the Office of State Revenue.

However, the City of Sydney's net revenue from fines was only $9.7 million, the spokeswoman said.

"Penalty notice fines, including those with demerit points, are an effective deterrent to those who fail to comply with the law," said a Transport for NSW spokeswoman. "The penalty level of an offence is determined through consideration of the impact to road user safety, the management of traffic and the environment."

The NRMA's Parking Strategy report, published in 2015, found the City of Sydney collected more revenue from parking fines than the combined take of Waverley, North Sydney, Woollahra, Marrickville and Fairfield local government areas.

Seven Sydney councils, led by Marrickville and Rockdale, increased parking fine revenue by more than 20 per cent in one year.

"Currently there is no legislative or administrative requirement for local councils to reinvest revenue collected from parking fines back into local road infrastructure improvements," the report said.

The NRMA noted that councils may lack the financial resources to fix roads: "However, a shortfall in revenue must not be addressed by unfairly targeting motorists as 'cash-cows'."

NRMA spokesman Peter Khoury??? said parking signs were often confusing, with "five or six signs piled on top of each other".

"By the time you've read them all, most people are guessing unfortunately as to whether or not they're parking illegally," he said.

"There is no doubt that the nature of signs - especially in the Sydney CBD - is a concern." ???

A parking fine is more than an inconvenience for people on modest incomes, according to Gerard Hayes, the NSW secretary of the Health Services Union.

"It can devastate their finances for months," he said. "Many of our members lead busy, stressful lives and occasionally they take a gamble and park somewhere they shouldn't. Unfortunately, revenue-hungry governments don't consider the social consequences of big fines for people on low incomes. Parking fines should definitely be reduced."

Many clients of the Redfern Legal Centre struggle to pay fines of all types.

"For people living week to week, large fines can leave them in a position where they may not be able to pay for their rent or put food on the table," Laura Bianchi, a solicitor specialising in credit, debt and consumer law at Redfern Legal Centre, said.

NSW's State Debt Recovery Office has "procedures" to help pay fines including work orders, time to pay arrangements and payments by instalments.

However, some people experiencing financial hardship or who have a mental illness or serious substance addiction may apply for a Work and Development Order, she added.

"If approved they can satisfy their fines through unpaid work with an approved organisation or through certain courses or treatment," she said. "It is possible to ask the State Debt Recovery Office to postpone enforcement of a fine or waive the fine in its entirety."