The days of the pneumatic tube may be ending. Banks' drive-through stations have long been overdue for a tech upgrade in an age of smartphones and tablets.

So they're doing away with their tubes (used to deliver documents, cash and sometimes lollipops to customers in their cars) and adding videoconferencing features to a channel that accounts for more than half of a bank's transactions in some parts of the country.

Such is the case for BBVA Compass' drive-through lanes in the Sunbelt region. The bank quietly introduced three videoconferencing devices at its drive-through stations in Texas in recent weeks. The software lets people do their banking with remote tellers or use the device the way they would use an ATM.

The test offers the latest example of a bank using tech to update its physical locations to improve the customer experience and potentially save on operational costs from centralizing tellers. Bank of America and Huntington have also been experimenting with video tellers at their drive-through stations. More common, but far from standard, are banks testing video tellers at kiosks in their branches.

In updating its drive-throughs, BBVA tried to create a dramatically different device.

"We don't want to call it an ATM," says Alex Carriles, director of self-service channels for BBVA Compass. Nor did the bank want the device to look like an ATM. The team sought hardware — and accompanying software — with a more inviting design, he says.

To figure out what that new design should look like, Carriles says the bank first studied drive-through lanes across the country — including at doughnut shops. After collecting ideas, BBVA partnered with its Spanish innovation unit and Wincor Nixdorf to create the machine.

Collectively, they worked to improve a decades-old experience that has often involved a garbled voice coming through hardware that required a customer to shoot money and documents through a pneumatic tube — and a teller serving multiple customers simultaneously. In a smartphone era, such an experience feels mediocre at best.

"We wanted to improve on it," says Carriles.

BBVA's new devices come with a large screen that adjusts to the height of the customer vehicle in two ways: One, the control buttons move after a person touches the top or bottom of the screen. Two, the camera detects the position of the customer's head in relation to the unit and adjusts the screen up or down.

"It's a friendlier interface," says Carriles. "The buttons are larger, wider and more spaced out."

In turn, consumers — possibly restricted by a seatbelt — can touch the larger control buttons more easily. Plus, customers only need to push one button if they want to interact with a video teller through a high definition video link.

"That just changes the whole dynamic," he says. "That teller is serving you one-on-one until you are done."

The drive-through device can function as a regular ATM.

Consumers can authenticate their transactions with an ATM card and PIN number. They can also answer questions from the video teller to access their accounts.

In BBVA's initial pilots, the devices can only dispense $20 bills. That will change, more bills will be added.

The video tellers, meanwhile, are located in the bank's call center in Texas. They are trained specifically for the role and use different software than traditional tellers.

The drive-through devices are more expensive than ordinary ATMs. However, they come with advantages that could help the bank save money and generate revenue, such as allowing the bank to centralize tellers — and potentially better serving customers during peak hours — and offering customers more functionality such as the ability to pay a mortgage or speak with a teller in Spanish, Carriles adds.

Industry wide, videoconferencing is expected to be used on more devices, including tablets.

Carriles, for one, sees an opportunity for specific use cases like talking to a financial advisor.

"Video could have a place within the mobile world," he says.