Border ID 

Along the northern border, U.S. and Canadian citizens will now have to show a passport or similar document, or two forms of identification such as a driver’s license and a birth certificate.

The rules will be felt along the Maine border with New Brunswick and Quebec, where people cross back and forth on a daily basis to visit family and friends, go to work or to shop.

U.S. customs and border protection officials say they will be flexible in implementing the new rules.