New rules requiring passports or new high-tech documents to cross the United States' northern and southern borders took effect Monday June 1st.  Travelers will need a passport, passport card or Enhanced Driver's License both to cross into Mexico and Canada and re-enter the United States.

The authorities reported no major delays in the crossing. Passenger and commercial traffic were flowing normally, with only brief warnings issued by U.S. border guards for those without the proper documents.

Anyone who failed to produce a passport or other satisfactory documents was given a small paper information leaflet with a banner of "non-compliant" under Washington's Western Hemisphere Travel Initiative rules, which also allow for use of enhanced drivers' licenses or NEXUS cards to enter the U.S. at land borders.