Only five per cent of ferry customers are using the Opal card. Credit:Peter Rae The Opal is cheaper than individual ferry tickets, but it is more expensive than individual fares using a MyFerry TravelTen card. It is also more expensive than individual trips using a bus TravelTen, but cheaper than individual trips bought separately. Mr Patokallio, a former travel publisher who now works in IT, said he created the site to vent his disappointment with the Opal card. "I was really looking forward to the Opal," said Mr Patokallio, whose regular commute is a ferry between Abbotsford and Darling Harbour. "It was like 'hey cool, I can finally use a smartcard instead of buying all these silly paper tickets'. And then I realised the way I actually commute it would cost me like $10 more per week for the same commute - that's ridiculous."

Using a train and a ferry within an hour can be counted as just one journey, hampering cost savings. Credit:Dallas Kilponen Rather than write an angry letter to Transport for NSW about the Opal, which he believed would invariably be cursorily dismissed, or pen an angry blog post, Mr Patokallio said a more productive idea would be to make a website that showed people how much they would pay. Mr Patokallio said his site showed that in those instances commuters save under Opal, they save a small amount. But it can be quite easy to be worse off by a large amount. "There's a bunch of cases, like transferring from bus to train for example, or using a ferry less than five days a week, where you actually lose a lot of money," he said. The main price incentive under the Opal card is that all travel is free after eight "journeys" in a week.

It would cost me like $10 more per week for the same commute - that's ridiculous. But one journey could be made up of multiple trips. Taking a bus to a train station and then catching a train within an hour would together count as one journey. In general the Opal works out better for people the more they use it. But Mr Patokallio said this did not reflect many people's lifestyles. "You might work from home one day, or somebody gives you a ride home from work on the way back, or you go out for dinner or something – you don't always commute like a clock, people's lives change," said Patokallio, who works from home on Mondays. Transport for NSW says that its analysis shows that just 7 per cent of people would pay more under the Opal, with another 7 per cent potentially paying more. Those paying more would typically be people who buy monthly, quarterly or yearly public transport tickets.

But the department has consistently refused to release the full analysis upon which these figures are based. Another Opal user, Paul Burke, a senior lecturer and fellow in marketing at the University of Technology, Sydney, has analysed the cost impact of the Opal on train travel in the afternoon peak hour. "For the off-peak morning traveller who returns during peak times, such as those working part-time or going into the city to do a spot of shopping, the paper ticket can actually offer a cheaper alternative," Dr Burke said. Under the pricing system for paper-based tickets, a return ticket bought outside of peak hour costs about 30 per cent less than one bought at peak hour. Even if you use the return leg of that ticket in the afternoon peak, that leg is priced at a cheaper rate. But under the Opal, if you return in the afternoon peak hour, you are charged the more expensive rate.

This means that a return journey from the city to Parramatta in the afternoon peak hour costs about $1 more under the Opal, compared to buying a paper ticket outside of the peak. On the same comparison, a return journey from the City to Blacktown costs about $1.50 more, while a return journey from the city to Bondi Junction costs about 60 cents more. Last week the Opal card became available at another 26 train stations in Sydney, and now operates on 120 stations in total. It will be across all train stations and on all buses by the end of the year, and will be introduced to light rail next year. At the moment it is restricted to two bus routes. A spokesman for Transport for NSW said more than 100,000 Opal cards had been registered, with more than 55,000 registered since the end of February. "The usage and uptake of the Opal card will continue to increase as we roll out across the rest of the train network and 5000 buses," the spokesman said. "The introduction later this year of Opal cards for the concession fare customers, such as children and seniors, will also lead to an increase to travelling with an Opal card."

The spokesman said MyMultis and periodical tickets such as monthly and annual tickets represent only about 3 per cent of all train tickets sold. Transport for NSW also criticised the site. "The Opal or Not website fare calculator is riddled with errors to the extent that it will mislead customers who want to compare ticket product," a spokesman said. "Around 90 per cent of our customers have the potential to be the same or better off under Opal," he said. "Customers wishing to obtain information about Opal should go to the Opal website or call Opal Customer Care on 13 67 25." But Labor's transport spokeswoman Penny Sharpe said the government should set up its own similar website to Mr Patokallio's to allow commuters to make their own comparisons.

"If you're serious about transparency you need to give commuters the best information so they can make the best choice for them," Ms Sharpe said. "They should have a similar fare calculation site." The most recent calculations on www.opalornot.com show that after about 20,000 comparisons, 61 per cent of users would pay more using an Opal. Loading Transport experts say the big problem with the Opal fare structure is that it penalises commuters from changing from one form of transport to another. Commuters have to pay twice when they make the one journey that requires a bus and a train, or a bus and a ferry.

Clarification: An earlier version of this story said more than half of all public transport users would pay more using the Opal card, according to the site.