The Chain of Rocks Canal is a navigational channel that handles all barge traffic passing through St. Louis. The I-270 bridge that spans the canal is a major commuter link between Illinois and Missouri. When it came time to replace the aging bridge and increase traffic capacity, it was critically important that the construction be executed in a manner that minimized impacts to the many stakeholders who travel these corridors every day.

Crawford, Murphy & Tilly (CMT) was selected by the Illinois Department of Transportation to lead the construction phase services for this complex project that also required close coordination with the U.S. Army Corps of Engineers and the U.S Coast Guard. The project included construction of a 1,980 foot-long, 94 foot-wide, steel girder bridge with a navigational span of 490 feet. Other project elements included levee construction, bridge demolition, retaining wall construction, pavement removal, interstate highway construction, and partial interchange reconstruction.