Dan Ryan Expressway (I90/ I94; 700 West; 2400 South) runs North South through Chicago. It crosses the South Branch Chicago River 4.3 miles from the river mouth.
The Federal Highway Act of 1956 established the interstate highway system. One of the roads in this system was the Soutwest highway (Dan Ryan Expressway). There was a controversy about the nature of the bridge crossing the South Branch Chicago River. One group wanted a bascule type of structure; the other argued for a fixed bridge. The U.S. Army corps of engineers, U.S. Bureau of Public Roads, and the Secretary of the Army approved a fixed bridge. It opened in 1965.
It is a steel and reinforced concrete bridge. The bridge length is 517 feet. It is 174 feet wide. There are 12 traffic lanes. There are emergency walks on both both sides measuring 2.2 feet. Bridge clearance is 60 feet. The bridge was constructed by the American Bridge Company. Cost was $1,178,566.