"To avoid having travelers in vehicles stop at border crossings, which could create significant traffic delays, U.S. Customs and Border Protection (CBP) is working to implement a face biometric entry-exit system in a way that poses the least impact on travel and trade," said the call for presentations. "This call is looking for innovative solutions to capture facial recognition quality photos from travelers in order to facilitate identity checks without requiring occupants to leave the vehicle."

In the call for proposals, DHS says that photos taken with such a system "will be used to validate the identities of the occupants and document their entry or exit from the United States." The paper also said that photos must be packaged and transmitted to "compare against DHS holdings to validate occupants' identities and document entry/exit." Which sounds a lot like a database of people leaving and entering the country — a requirement that privacy-minded individuals and advocacy groups will likely take issue with. As noted by Gizmodo, DHS has a clause in the request for proposals that asks for "innovative approaches that allow for anonymization of U.S. citizen traveler data who are not 'in-scope' for biometric exit and privacy controls that limit the collection of such information."