Visits to the United States by Canadians have dropped since 1 June, when the Western Hemisphere Travel Initiative began requiring new documentation for cross-border land travel.

Napolitano said U.S. border officials have been giving travelers between the two countries a document that outlines the new rules.

Schumer said his concern is for people who do not try to cross the border because they think they need a passport. Only about one-third of U.S. citizens and Canadians have passports, he noted.

First-time passports cost $100 for applicants 16 or older, and $85 for children, making a visit to Canada expensive for many Americans even before they put gas in their car.

Less-expensive options include:

• Wallet-sized passport cards, which cost $45 for citizens age 16 and over
• An enhanced adult drivers license (for adults) from a state motor vehicle department
• Enrolling in one of three trusted traveler programs — NEXUS, SENTRI, or FAST — to become a pre-approved, low-risk traveler.
• For children age 16 and under, an original copy of their birth certificate

Land travel between the United States and Canada was declining even before the new travel requirements, according to Joanne Ferreira, a spokeswoman for U.S. Customs and Border Protection. “There are different factors that could be affecting the travel, including the economy, weather and exchange rates,” she said.

The Buffalo field office of Customs and Border Protection reports travel fell 8.2 percent from 1 June to 30 July last year compared to the same period in 2007. This year, the decline was 13.3 percent drop over that same period.