The Honoré Mercier Bridge spans the St. Lawrence River and Seaway on the western side of the Island of Montreal. It is located between the Champlain Bridge and the mouth of Lake St. Louis. The bridge has direct connections with Highway 20 in LaSalle, and with Highway 132 to Châteauguay, through the Mohawk Territory of Kahnawake.
The portion of the bridge under the jurisdiction of the Corporation is located on the South Shore of the St. Lawrence River.
Today, approximately 30 million vehicles cross the Honoré Mercier Bridge every year.
The bridge was originally 4,464 feet 11 inches (1,361.25 m) long. Its main steel span was 399 feet 9 inches (121.87 m) long and consisted of 11 steel spans and 31 reinforced concrete spans. The roadway was 26 feet 4 inches (8 m) wide, with a 3-foot 6-inch (1.06 m) sidewalk.
The federal portion of the Honoré Mercier Bridge and its approaches, which came under the jurisdiction of The Jacques Cartier and Champlain Bridges Incorporated on October 1, 1998, are divided into four sections, built in 1958 and 1959.