In between reading work emails on her phone – and answering questions from a reporter who inadvertently got on her carriage – the Transport Minister’s eyes repeatedly wandered to the belt clip of a woman sitting diagonally across.

The woman had an Opal card fixed to her jeans. She looked across and Berejiklian was happy to explain the curiosity.

''I’m the Transport Minister and I was just saying I like the way you’ve got the Opal thing there,'' Berejiklian said. ''Do you like using the card?''

The response – instructive, perhaps – was a bit of yes and no.

''It’s easy,'' said the woman, Lindy Klein, of Sydney’s new public transport smartcard.

The Opal offers discount fares for travelling before 7am. Klein says she liked to take advantage of these, which also helps her to get home earlier to her daughter.

But there were some issues, Klein told the Minister.

''It’s linked to my partner’s credit card but it keeps losing the link,'' she said. ''That’s probably not the Opal’s fault. I suspect it's something I’ve done.''

The next few months pose the biggest test yet for Berejiklian and the Opal smartcard, the public transport ticket that the Minister has taken political ownership of in a way she need not have.

''Look at the Opal ticketing system – we started that project from scratch,'' the Minister said in a promotional video released a couple of months ago.

That is not quite right.

The origins of the Opal card start with the former Labor government's 2008 decision to cancel its disastrous ''T-Card'' contract, which at one stage was to have delivered commuters in Sydney a smartcard in time for the 2000 Olympics.

Instead, Sydney residents have had to wait almost 15 years for an electronic smartcard that they can hold on to and that they can use across all types of public transport.

After a bidding process that started in early 2009, the contract for the Opal card was signed by former transport minister David Campbell in May 2010.

This was almost a year before Berejiklian became the Transport Minister. The Opal system has since been extended across Sydney’s transport system under Berejiklian’s watch, but largely according to the terms of that 2010 contract.

''We inherited the contract,'' Berejiklian says. ''But in terms of decision-making around the team, the implementation, that was completely from scratch.

''I was not satisfied with the team I inherited. I was not satisfied with the team our private sector partners had. So we started from scratch in terms of recruiting people who had actually done this before.''

Berejiklian and her recruits have set September as a key date for the card.

From that month, many public transport users will need to begin switching to the Opal card to get cheaper fares for off-peak and regular travel. Berejiklian says she is confident the switch will prove popular – though other types of paper tickets, such as the TravelTen for buses, will probably remain for at least another year.

''Certainly in my mind I hadn’t anticipated the take-up would be so strong up to this point,'' she says.

''I hadn’t assumed that we would nearly get to half a million registered cards already ... even though the rollout on buses is not even a third of the way through.''

Internal reports obtained by Fairfax Media using freedom of information laws also point to the general popularity of the card.

Surveys show a result of eight out of 10 for ''customer satisfaction''.

But there are also a myriad of gripes with the card. Regular correspondence to Fairfax Media reveals multiple causes of dissatisfaction.

Some of the concerns are technical. The opal.com.au website, for instance, is at times intermittently inaccessible. Other commuters say they have been overcharged due to glitches with card readers, and calling up the info line for a refund can be a time-consuming hassle.

And then, if card readers do not work, Sydney Trains staff need to close station gates down to reboot them.

A commuter who witnessed a reboot of barrier gates on Thursday just before 9am at Town Hall said it resulted in a five-minute delay in getting out of the station and chaos among passengers, who could not move.

''The staff at the station yelled out that the Opal readers weren't working and that they needed to reboot them,'' the commuter said.

''It wasn't all of them but two of the Opal readers weren't working, which meant they had to restart about half of them. There was just a sea of people and no room whatsoever to move.''

This problem is compounded by the current inability of employees of the state-run train and bus networks to help commuters with their Opal cards. Instead, Sydney Trains staff are directed to refer concerns to the private operators of the Opal system. (In time, Berejiklian says, government employees will also be trained to deal with Opal issues.)

Other complaints relate to the fare structure.

Berejiklian says that 90 per cent of people should be paying the same or less under the Opal scheme, but scores of commuters have estimated they will be paying more.

This might be because cost-effective quarterly and yearly tickets are being retired. Or it might be because they do not travel regularly enough to hit free trips after eight in a week.

Some complaints  concern the way in which Berejiklian is encouraging people to link their accounts to their credit or debit card.

About two-thirds of users have linked the Opal card to their accounts, which the Minister credits as a key achievement. Comparable systems are understood to have less than 20 per cent of travellers signing up to linked accounts.

One concern is that the $40 minimum online automatic top-up for adult Opal cards is too high for irregular users.

Transport for NSW said the $40 top-up reflects a common amount spent on public transport in a week. But Tracy Howe, chief executive of the Council of Social Service of NSW, said the $40 minimum was an ''impractical amount for automatic top-up for people on low incomes''.

''Many households’ bank accounts come down to zero between pay days and getting hit with an unexpected $40 top-up fee towards the end of the pay period can cause further financial hardship,'' she said.

The surveys Fairfax Media has seen shows the Opal card remains, overall, a popular initiative for Sydney public transport users who have waited too long for a new ticketing system.

If the complaints stick, Berejiklian may regret not sheeting more of the responsibility for the project back on those who drew up the contract.

Facts and figures

Number of Opal cards issued: 450,000
Types of paper ticket to be retired by September 1: 14
Percentage of users who make at least eight journeys a week: 40
Percentage of users who choose to link Opal to their bank account: 70
Percentage of trips that users forget to tap off: 3

Cost of the Opal card initiative: $1.2 billion