For Americans headed to Montreal or Canadians visiting Michigan's Mackinac Island, those trips get a little more complex this summer.

As enhanced border crossing requirements loom, more states and provinces are putting in place the tools needed to make it easier for people to go between the U.S. and Canada.

There are still a few loose ends, but officials with U.S. Customs and Border Protection say they will be ready June 1, the day the United States fully implements the Western Hemisphere Travel Initiative.

The initiative strengthens documentation requirements for everyone entering the country, calling for passports or special driver's licenses.

The requirements will be in effect along the entire U.S. border with Canada. The initiative does not affect Mexican nationals, who are already required to present a passport and visa to come into the U.S.

Vermont, New York, Michigan and Washington state and the province of Quebec are the only places issuing enhanced driver's licenses, according to the customs agency. The license is designed for travel into the U.S. by land or sea.

Extra documentation and an interview is generally required to get the special licenses, which are considered secure.

Homeland Security delayed full implementation of the travel initiative after howls of complaints from officials in border states.

U.S. Sen. Patrick Leahy, a Vermont Democrat, helped pass the legislation that delayed full implementation.

"The extra time has helped avert a major mess at the border," Leahy said. "That would have been an economic shock wave that would have hurt Vermont and other border states. Federal agencies today are better prepared, and more Canadian visitors are aware that the change is coming."

Over the past year, customs officials have installed scanners at most of Vermont's border crossings that can read chips in enhanced driver's licenses. The scanners reduce the time every person spends at the border, said James McMillan, the customs agency's port director for Highgate Springs, at the north end of Interstate 89.

Over several hours, the time savings can be significant, said John Makolin, the CBP area port director for Vermont and New Hampshire.

"It does add up and it may seem incidental, but as time goes on and the document gets out there, it's quicker, quicker, quicker," Makolin said.

The new border policy will quickly be tested. The Quebec holiday of St. Jean Baptiste Day is in late June and Canada Day is in early July, both of which traditionally bring Canadian travelers into the United States.