Passport cards are smaller than a passport book and not available to use by air travel. These cards were implemented for land and sea travel to the United States, Canada, Mexico, the Caribbean and Bermuda. Passport cards are just as efficient as passport books but are much smaller and much less expensive. United States residents can use their passport card to cross the U.S./Canadian border by land.
The Enhanced Driver's License is being issued to residents of Michigan, New York, Washington and Vermont as of 2010. The EDL look like your regular driver's license with the addition of a micro-chip embedded in it that transmits your passport information to border control agents when it is scanned. The EDL is fairly new as of 2010 and cannot be used for air travel between Canada and the United States.
The Western Hemisphere Travel Initiative has a trusted traveler program for travelers that cross the United States/Canadian border frequently. For Canadian border crossing, the NEXUS card is used by travelers, which designates them to a specific lane at the border, which allows you to faster cross the border than in any other lanes. NEXUS cards can be applied for with the U.S. Customs and Border Protection for a fee of $50.
