Детройт-Виндзор
Вашпост - статья про мост между американским Детройтом и канадским Виндзором.

This is the busiest border crossing in North America -- more goods pass between Detroit and Windsor than between the United States and the entire European Union
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one truck over the Ambassador Bridge every six seconds
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90 percent of all Canadians live within 100 miles of the border
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The U.S. Border Patrol, for example, had 9,091 agents at the southern border before Sept. 11, and only 334 agents on the northern line, which is more than twice as long.
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Canada sends 87 percent of its exports to the United States, so its emphasis has always been on facilitating trade. The United States sends 25 percent of its exports to Canada, the top trading partner of 38 states, but its economy is not so reliant on cross-border trade.

Там же - об американо-канадской границе вообще:

Before Sept. 11, for example, half the border's 126 official crossings were unguarded at night; now the orange cones that used to block U.S. entry roads have been supplemented by people.