Customs and Border Protection (CBP) plans to have ready its network infrastructure by FY ’19 to support the build out of a solution that collects the biometrics of travelers departing the U.S., part of what it describes as a three phase effort to deploy a biometric exit system.

The agency is seeking $90.6 million in FY ’18 funding to continue its work on the biometric exit system, which initially is focused on facial recognition of travelers at the departure gate before they board a flight to leave the U.S.

CBP is currently doing limited operational evaluations of its biometric exit solution at one airport for one international daily flight and plans to expand this effort to seven more airports throughout the summer beginning in June.

The agency says its “Biometric Pathway Backbone” will lead to a “transformation of air travel” based on biometrics to improve security and the traveler experience. The backbone will also pave the way for investments by airlines and airports, according to CBP’s FY ’18 budget request.

The backbone “will allow for private sector investment in front end infrastructure, such as facial recognition self-boarding gates, self-service baggage drop off kiosks, and other equipment; this will lead to a biometric-based entry/exit system that provides benefits to air travel partners,” CBP says. “The use of biometric technology is envisioned to eventually replace identity documents such as passports and driver’s licenses.”

The entry process currently uses fingerprint technology to prove that a person entering the U.S. is the same person that applied for and received a visa overseas. CBP later this year plans to begin evaluating facial recognition for use at its arrival stations.

The budget documents sum up much of that CBP officials have been slowly rolling out since late last fall in terms of transforming the process for verifying the identities of foreign nationals entering and exiting the U.S. However, they add some additional clarity in terms of having the private sector make investments in biometric technology at the front end of the departure process.

CBP plans to spend $1 billion over 10 years on revamping the biometric entry and exit solution. The funding comes from fee surcharges authorized in the federal FY ’16 spending bill.

The FY ’18 budget request mentions three phases in transforming the biometric entry and exit system. The first phase, which is ongoing, is beginning the real-time electronic biometric matching at the boarding gate, “which will result in a biometric confirmation being written into the crossing record.”

The 9/11 Commission recommended biometric verification of arriving and departing foreign nationals to better track visa overstays. CBP currently relies on biographic checks to verify the departure of foreign nationals from the U.S. by plane.

The second phase will focus on building out the enterprise backbone and generating the biometric exit solution,” with the capabilities eventually leveraged for the entry process, CBP says.

“The purpose of phase two is to develop the overall IT infrastructure that the front end cameras can ‘plug in to’ once CBP is ready to deploy the collection capability,” the agency’s budget request says.

In the third phase the backbone will be scalable to enable nationwide deployment of the solutions.

CBP also says that in FY ’18 it will continue efforts to bring a biometric exit solution to land ports of entry. The agency already tested various biometric technologies at the Otay Mesa, Calif., land port of entry, which helped demonstrate the feasibility of facial recognition against databases of different sizes. CBP says that as part of its land border biometric efforts it will test “emerging technologies to capture biometrics at speed.”