The Ambassador Bridge is a suspension bridge that connects Detroit, Michigan, in the United States, with Windsor, Ontario, in Canada. The bridge is owned by the Detroit International Bridge Co., which is controlled by Grosse Pointe businessman Manuel "Matty" Moroun. The Detroit-Windsor Tunnel also connects the two cities. A 2004 Border Transportation Partnership study showed that 150,000 jobs in the region and US$13 billion in annual production depend on the Windsor-Detroit international border crossing. It is the busiest international border crossing in North America in terms of trade volume: more than 25 percent of all merchandise trade between the United States and Canada crosses the bridge.
The bridge, over the Detroit River, had the longest suspended central span in the world when it was completed in 1929—1,850 feet (564 m), a title it would hold until 1931. The total bridge length is 7,500 feet (2,286 m). Construction began in 1927 and was completed in 1929. The architect was the McClintic-Marshall Company of Pittsburgh, Pennsylvania.
The bridge is styled in a mixture of Art Deco and Streamline Moderne architectural designs, with some Gothic architecture blended in. It is made primarily out of steel; however, the two main towers on each side of the river are made of a steel-silicon alloy which rise up from concrete piers. The towers rise 386 feet (118 m) above the river, and plunge 115 feet (35 m) below the surface of the Detroit River. The bridge is made up of 21,000 tons of steel, and the roadway rises as high as 152 feet (46 m) above the Detroit River. Only the main span over the river is supported by suspension cables; the approaches to the main pillars are held up by steel in a cantilever truss structure.
The only bridge sidewalk on the south side used to allow pedestrians and bicycles, but security concerns after the September 11 terrorist attack had it closed. When the painting is being done on the south side of the bridge span, the sidewalk helps accommodate equipment and decrease the length of the lane that is cordoned off for painting.
The four-lane bridge carries more than 10,000 commercial vehicles on a typical weekday. A major redesign of the U.S. plaza completed in July 2009 provides direct access to Interstate 96 and Interstate 75 on the American side and Highway 3 (and indirectly with Highway 401) on the Canadian side. Currently, traffic coming off the Ambassador Bridge on the Canadian side must travel through heavily populated residential and business areas on Highway 3 before accessing Highway 401. The Ambassador Bridge enhancement project calls for a twin span to be built across the Detroit River.
Granite blocks, originally used on the U.S. side, were given to the Windsor Parks & Recreation Department, and now grace many of the pathways in Windsor parks
The bridge was featured in the films 8 Mile, Crossing the Bridge, Grosse Pointe Blank, Sicko and Bowling for Columbine. It can also be seen in the opening scenes of the film Four Brothers and in an episode of the series Biker Mice From Mars ("The Motor City Maniac", 1994). It is also featured in the novel Middlesex by Jeffrey Eugenides. It is featured in Sam Roberts' music video for the song "Detroit '67".
