NEW YORK ( MainStreet) — A new option for personal banking is in the works: your local subway station.

Over the last several months, Chicago has introduced a new program called the Ventra card, a contactless system that will replace standard magnetic tickets for public transportation. While much has been written about it , as far as most passengers are concerned the changes are largely cosmetic. We still pay for a card to keep in a wallet and get on the train; tapping vs. inserting makes astonishingly little difference.

What's new is that Ventra can also serve as a personal bank.

Every Ventra card is linked to the MasterCard network and is accepted as a functional debit card wherever MasterCards work. Consumers can load their cards anywhere that sells public transit cards, not only at every train station around the city but also at the innumerable convenience stores that offer the same service. Anyone who re-loads an existing card gets an account, complete with an ID and account number and protections against theft, fraud and loss.

In fact, in most structural senses a Ventra account is little different from a standard checking account. That's the entire idea.

"This was developed with the concept of not only having dual purpose in a card, obviously a card that allows you to get on trains, subways, etc., but also having a ready solution that you can top up with cash or get deposits on," said Mark Puttman, a senior Vice President with First Data, which helped build the network on which Ventra runs. "It's to help mainstream individuals that have historically been left out of the financial world."

The goal is to create a banking product that's available to the entire city, one which could have a profound impact on Chicago's unbanked population.

Nearly one in twelve American households are what is known as "unbanked," meaning that they operate on a near-total cash basis. For most Americans the idea of not having a bank account is an odd one, particularly as debit and credit cards have become such a way of life that paying cash has increasingly become the exception rather than the rule. For many people, however, it's day to day life.

People remain unbanked for a wide variety of reasons, from not having physical access to a branch to concerns about expense. Most checking and savings accounts charge a fee for failing to have a minimum balance, and for someone who needs every dollar, that often makes having the account too expensive. Unfortunately, it also can lead to simply more expenses down the road.

"There's a lot of problems with being unbanked," said Jason Alderman, a senior director with Visa's financial literacy program. "I understand a lot of folks who feel like their prior relationships haven't worked for them and they've created workarounds. But I think that most experts would agree that it's a much more expensive proposition both in terms of your time and your dollars."