I-270 North Design-Build

Carrying 140,000 vehicles daily, the I-270 North corridor through North St. Louis County is among Missouri’s most heavily-traveled interstates. MoDOT took a design-build approach to modernize the highway, fix deteriorating infrastructure and reduce traffic congestion. The project improved safety, mobility and accessibility on the mainline, interchanges and outer roads along a 9 mile stretch of I-270 from James S. McDonnell Boulevard to Bellefontaine Road.

As a member of the design-build team, TREKK designed drainage improvements from just west of Old Halls Ferry Road to Bellefontaine Road. Drainage improvements included open and closed drainage systems that met MoDOT design criteria, as well as detention basins that met the Metropolitan St. Louis Sewer District’s criteria. TREKK worked closely with the roadway designers to develop drainage plans for a phased construction approach, which included planning for interim conditions. 

Roadway improvements in this area included bridge replacements, the addition of a new bridge, reconstruction of outer roads and ramps, a roundabout and an additional lane in each direction on I-270.