A thousand birthday greetings for US-Canada Thousand Island Bridge

The Canada-US Thousand Island Bridge system celebrated its 80th birthday in August with presentations and an open house at its US headquarters. The 33.7km three-bridge system over the St Lawrence River took 16 months to build and was completed 10 weeks ahead of schedule. It runs from Collins Landing near Alexandria Bay in the US state of New York to the small town of Ivy Lea in the Canadian province of Ontario. The system connects US Interstate 81 and Canada’s Highway 401, a major motorway between Montre
August 21, 2018 Read time: 2 mins
The Canada-US Thousand Island Bridge system celebrated its 80th birthday in August with presentations and an open house at its US headquarters.


The 33.7km three-bridge system over the St Lawrence River took 16 months to build and was completed 10 weeks ahead of schedule. It runs from Collins Landing near Alexandria Bay in the US state of New York to the small town of Ivy Lea in the Canadian province of Ontario. The system connects US Interstate 81 and Canada’s Highway 401, a major motorway between Montreal and Toronto, ending in Windsor on the Ontario border with the US state of Michigan.

The 1,370m crossing over the American channel of the river - from the US mainland to Wellesley Island - consists of a suspension bridge with a main span of around 245m and nearly 46m of clearance above the river.

The Canadian crossing includes the 183m continuous Warren Truss span connecting Hill Island to Constance Island, a steel arch of 106m spans from Constance Island to Georgina Island and a suspension bridge of 229m from Georgina Island to the Canadian mainland. The Canadian span from abutment to abutment is 1,015m and the suspension span provides 37m of river clearance.

The boundary at the International Rift boundary – the channel between Wellesley Island and Hill Island - is bridged by two parallel 27.4m rigid-frame arched spans of reinforced concrete with masonry facing. Originally there was only one bridge at boundary but due to increased traffic it was twinned in 1959.

Operation of the Thousand Islands Bridge system is shared under a joint agreement that created the US based Thousand Islands Bridge Authority which estimates that there are 2,000 vehicle-cross the annually. The system’s original consulting engineer was Robinson and Steinman of New York City that  continues to do so today but as 3220 Parsons Transportation, notes the authority.

Road Structures

For more information on companies in this article

Related Content

  • Virginia project for Parsons
    June 28, 2016
    Parsons has won a deal to design and installation of the nation’s first all-lane, dynamic-priced tolling system on a 16km segment of Interstate 66 in Virginia. This stretch of highway runs from Interstate 495, the Capital Beltway, to US Route 29 in Rosslyn, Virginia. Dynamic tolling, able to adjust toll pricing to demand, will operate in the peak travel direction during weekday rush hours. This will help lower traffic congestion into and out of US capital Washington, DC.
    Read More
  • Sweden’s Tjörnbron Bridge to get replacement cables
    May 30, 2018
    SwedenSwedish contractor Svevia has been commissioned by the Swedish Transport Administration (Trafikverket) to handle cable replacements on the Tjörnbron Bridge. Replacement is expected to start in 2019 for completion by 2025. Svevia project manager Johan Söderberg said the work will be complicated, not least because traffic must continue to us the bridge. He reportedly said that much of the work will have to take place at night, in the summer and in good weather. The 664m-long cable stayed Tjörn Bridge,
    Read More
  • $250 million for Oregon-Washington bridge replacement
    July 10, 2025
    Oregon and Washington will provide $250 million for the Hood River-White Salmon Bridge replacement.
    Read More
  • German government to adhere to Fehmarn Belt tunnel plans
    April 30, 2015
    Germany is to adhere to plans for a tunnel between Fehmarn, Germany, and Lolland, Denmark despite criticism over the cost and a delayed schedule. Denmark alone is likely to foot the €7.4 billion bill for the prestigious Fehmarn Belt Fixed Link immersed tunnel while Germany will pay for only access roads and other connections on its territory. Angela Merkel, Chancellor of Germany, said her government and transport authorities will respond to more than 3,000 objections over the construction of the tunne
    Read More

Highlighted Content