In yet another example of the push toward greater automation, Delta Air Lines is the latest U.S. carrier to test automated, do-it-yourself turnstiles at departure gates.

The technology, likely to spread in the years to come, allows passengers to scan their own boarding passes and enter the plane without the help of an airline employee, reports the Star Tribune.

Delta recently tested the machines in Atlanta and Las Vegas, but the carrier hasn't said if there's to be further testing, nor did it provide customer feedback details.

DYI boarding isn't new. Continental Airlines, before its merger with United, began testing similar equipment Houston's George Bush Intercontinental Airport, and SAS and Lufthansa are just two of the some 20 big carriers that have been using self-service boarding gates for years, according to the Tribune.

The push toward self-ticketing and boarding is obviously: the bottom line. Not only could do-it-yourself boarding lighten the need for airline staff at the gate, proponents say it can free up staff to monitor carry-on luggage and be available for those who need real assistance.

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"Virtually all air carriers that have tried them have realized an operational and economic benefit from them," Samuel Ingalls, assistant director of information systems at McCarran, told the Tribune. "Additionally, the customers like to be empowered over all of the various processes."

The system has gotten positive reviews from some frequent and tech-savvy travelers.  But critics say that, amid ever-changing technology, it may take time for all consumers to get used to the devices, and may pose a security risk.