M3 Engineering was selected for the design of the replacement of the existing Functionally Obsolete, three span bridge on JS McDonnell Boulevard. Bridge No. 164, which has an ADT of nearly 15,000, provides vital access to businesses north of Lambert Airport. The bridge spans Coldwater Creek and is only 1,200 feet from Lambert’s Crosswind Runway 6/24 making it subject to FAA’s Part 77 regulations that restrict the height of construction equipment from obstructing navigable airspace. The bridge is located within a FUSRAP site, so M3 worked with USACE to ensure that any disturbed subsurface material followed radioactive safety protocol. A floodplain study of Coldwater Creek was prepared to demonstrate no impact on the 100 year water surface elevation.