Public transport fare evaders cost NSW about $120 million a year, according to the first detailed survey of Sydney's bus, rail and ferry passengers.

The survey of almost 70,000 people found more than one in 10 on public transport in Sydney dodged fares - a much higher percentage than previously thought.

Fare-evasion rates in Sydney are comparable to rates reported by other states 

Gladys Berejiklian, Transport Minister

Bus commuters were the most likely to evade fares, often by travelling further on tickets they had paid for.

Fare evasion

Just the ticket: Transport officer Arron Cutugno checks on bus passengers at Bondi Junction. Photo: Ben Rushton

But train passengers cost the state the most. This is because train travellers who evade fares tend not to buy a ticket at all, and because train fares are more expensive than buses.

In response to the survey, conducted in November 2012 for the Bureau of Transport Statistics and released following inquiries by Fairfax Media, the state government has started to change the way it tackles fare evasion.

Last year it started to refuse to sell concession tickets from vending machines at multiple Sydney railway stations. This prompted a 10 per cent drop in concession ticket sales.

It has also directed a new division of 150 transport officers to check on concession holders, and bus passengers who travel for longer than their tickets allow.

The survey found the Carlingford line had the highest rate of fare evasion among trains in Sydney, although that line is lightly used. Among heavily used lines, the eastern suburbs has the highest rate of fare evasion.

Bus passengers in the inner west are most likely to evade fares, followed by those in the eastern suburbs and north Sydney.

This suggests it is harder to dodge paying the correct fare on bus routes operated by private companies, most of which are in Sydney's west.

Transport Minister Gladys Berejiklian said the measures the government had taken in response to the survey had started to work. The government expects to sell 4 million more adult tickets on public transport this year, and 4 million fewer concession tickets, because of its focus on people buying concessions.

''Fare-evasion rates in Sydney are comparable to rates reported by other states which have similar public transport systems and equally vigorous assessments of fare evasion, although there is certainly room to drive the rate lower and I am determined to do that,'' Ms Berejiklian said.

''The rollout of the Opal card will have a significant impact on fare evasion, because people pay for exactly the distance they travel and there is a penalty if they don't tap on or off.''

On Oxford Street on Wednesday night, Alicia, 27, from Newtown said she had been fined $200 by transport officers after she was caught without her concession card at Bondi Junction.

''I'm pretty annoyed,'' she said. ''I've missed my bus. I can understand why they pulled me up … but its more than a parking ticket - double.''

Derrek, 27, from Ireland was also hit with a fine for "overtravelling". He used a MyBus 1 when he needed a MyBus 2.

"I didn't know how many sections I was going," he said. "It's confusing."

James, 33, sees the transport officers often on his route to the city through Bondi Junction. He has been caught out a few times in the past.

"I’m more careful now,’’ he said on Wednesday night. "But from my point of view, it’s not worth paying full price - [the service] is really expensive for what it is."

About 8 per cent of train passengers evade fares, costing the state about $70 million a year. About 15 per cent of bus passengers evade fares, costing $50 million, and about 5 per cent of ferry passengers evade fares, costing about $2.5 million.

Ferry passengers on routes that do not run through Darling Harbour and Circular Quay have high rates of fare evasion, but most passengers enter or exit through those wharves. People are also more likely to evade fares at weekends than on weekdays.