The Chicago metro, like the London tube, uses contactless payment cards to pay for journeys or you can load a one day, three day or seven day pass and it will use that. I tried using my Mondo card to pay for a ticket (contactless payment), but the machine didn’t like the card. Interestingly though my mondo app showed USD 3 was taken and then immediately refunded, so not sure why it didn’t work. Anyone any idea? Unfortunately it was the only wireless card I had on me so had to purchase one of their Ventra cards (like Oyster).
I successfully added passes tomy Ventra card with my Monzo card while in Chicago. I did have to select “credit card” on the machine to do this, but it seemed happy with this and the payments went through.
Other people successfully used their contactless cards to pay for journeys. However, unlike London, there is no automatic capping, so it may still be better value to get a Ventra card and pay for a pass if you will be making a lot of journeys.
I thought it could be useful to add a recent experience - my Monzo card worked fine on the turnstiles this week in Chicago, both with the physical card and Apple Pay. I had issues with other UK cards, but I imagine the Monzo worked because of its support for contactless magstripe mode (whereas I’d guess other cards only support EMV contactless).