Background

The Thousand Islands crossing, constructed 1936 to 1938, extends from Collins Landing near Alexandria Bay, New York to Ivy Lea near Gananoque in the Province of Ontario, and connects Interstate Highway 81 in the U.S. with Highway 401 in Canada. The eight and one half mile long crossing consists of two suspension bridges, a steel arch span, two reinforced concrete rigid frame bridges, a continuous truss bridge, and connecting viaduct spans and approach roadways.  Based on the findings of the Northern New York Border Crossing Study, the ability of these bridges to process all the traffic that arrives in an hour will be exceeded.  The bridges will have reached their vehicle processing capacity, which will result in backups of traffic on the approaches waiting to cross over these bridges.

Although this two-lane structure system has been basically unchanged since 1938, a substantial investment has been made in its continuing maintenance.

The Thousand Islands crossing provides a direct connection between Canada's major east-west highway Route 401 and US Interstate 81. It is the seventh busiest US/Canadian international commercial crossing serving over 500,000 trucks per year.  Commercial traffic is forecasted to more than double in the next twenty-five years.  Annual passenger traffic is currently at 1,700,000 vehicles per year, of which over 70% are recreational in type.  Growth in passenger traffic is expected to be modest in the next twenty-five years.  The vehicle carrying capacity of these bridges is more greatly affected by commercial vehicles given the steepness and length of the bridge grades.  Capacity alternatives/options are relatively open since the land around the existing structures' touch down points is generally free of development.