Travelers wait in line at Dulles International Airport for a flight to Saudi Arabia. (Jahi Chikwendiu/The Washington Post)

Even while domestic traffic has lagged, international travel through Dulles International Airport has grown significantly. But for some U.S. travelers that has also meant longer lines when moving through customs.

To help speed travelers through the lines, officials at Dulles announced this week they are joining a growing number of U.S. airports that accept Mobile Passport — an app designed to replace the traditional blue-and-white paper declarations travelers must fill out when entering the United States.

The app, developed in conjunction with U.S. Customs and Border Protection, enables those with a U.S. or Canadian passport with a B1 or B2 visa status to go to a special lane for screening once they land at a participating airport. Travelers create a profile on the app using information from their passport. Families traveling together should enter their information on one device. Once they land and have a working signal, travelers are able to submit their responses electronically and then proceed to designated “Mobile Passport Control” signs where their CBP-generated code will be scanned from their phone. The app enables them to skip the general line used by those who fill out paper forms.

“At Dulles International, we never stop looking for ways to make the journey easier and more enjoyable for our travelers,” said Chris Browne, airport manager for Dulles. “Together with our partners at Customs and Border Protection, we are proud to introduce the Mobile Passport app as the latest innovation to make international arrivals an even smoother process.”

Two years ago, CBP officials announced they would add 40 customs officers to reduce waiting times for international travelers at Dulles. The move came after Sen. Mark Warner (D-Va.) raised questions about why some travelers were waiting more than an hour to be screened.

Correction: An earlier version of this report incorrectly referred to U.S. Customs and Border Protection.