One potential pitfall of upgrading TransLink’s fare card system to accept multiple payment options such as credit cards and mobile phones could be multiple charges for some riders.

The possibility some riders could be billed more than four times the price of a one-zone fare for a one-zone trip is one reason the transit authority is urging riders to ‘tap their card, not their wallet,’ so there’s no chance a confused Compass card reader could bill the wrong card.

But an activist who watched a fare card system in Chicago designed by the same contractor allegedly overbill many riders says it shouldn’t be up to passengers to avoid surprise extra charges.

“Charging people twice for the same ride – that’s a design flaw,” said Chicago freedom of information activist Jason Prechtel, pointing to a class-action lawsuit against that city’s Ventra card that was sparked by some riders claiming they had been double-billed.

“I was writing about this stuff in 2013 and 2014 and to read about this in 2018 – it boggles my mind. To a certain extent, I had assumed that because of the negative publicity they had learned their lesson in some of these issues,” he said.

Right now, it’s just Compass Cards that are charged when riders tap them against Compass readers. On the SkyTrain, a rider can tap on with one reader and tap off on another, with the system calculating the correct fare. A discounted one-zone trip is $2.20.

Now, TransLink is upgrading the capability of the Compass readers so they can accept payment from credit cards and mobile phones. The idea is to make the system more accessible to tourists or infrequent riders.

That change could introduce complications when paying for a trip by putting multiple payment options near the scanner like a wallet, which TransLink says is weighted to read a Compass Card but may read a contactless credit card instead.

For example, tapping onto the SkyTrain with a Compass Card, and out with a credit card, results in two maximum three-zone charges. That’s because the system determines that the first Compass Card never tapped out and bills it the maximum three-zone discounted fare of $4.30.

And when a credit card taps out, the system determines that the rider didn’t tap in correctly, and bills the credit card the maximum three-zone non-discounted fare of $5.60.

In this scenario, the total cost goes from $2.20 to $9.90 – more than four times higher.

TransLink’s solution has been to launch a campaign telling users to “tap their card, not their wallet.” This would help riders avoid the confusion and make sure the system only has one card to read. Anyone who believes they have been overcharged will be able to call TransLink and talk to customer service.

But Prechtel said he’s surprised that the technology hasn’t evolved to be more forgiving to riders. He says he wants some way of ensuring that if someone accidentally taps a wallet full of contactless cards, the system can read all the cards and pick the one that was used to tap into the system.

“I don’t feel like that would take a burdensome level of extra programming to implement,” he said. 

A TransLink spokesperson said the agency had consulted with cities that had systems built by Cubic Transportation Systems including Chicago and London, and had used that experience to improve the planned rollout in the spring.

Stickers and warnings are plastered on Compass readers in Skytrain stations and on buses.

There are some differences in the system – the Chicago class-action plaintiffs complained they had been double-charged in two cards at once, which TransLink stresses will not happen with the Compass system.

In Chicago, court documents say the class-action lawsuit has now been dismissed because a principal plaintiff died.

The Chicago Transit Authority didn’t return calls by deadline.