Missouri Department of Transportation—Route 364/Route 141 Interchange Improvement Project

The traffic volumes at Route 364 and Route 141 interchange in St. Louis County have grown significantly over the last decade leading to daily congestion, long delays, and increased crash rates. Limited funding and various environmental issues challenged the project team to develop an innovative design to improve safety and mobility at the interchange. That design went beyond traditional roadway widening by constructing a displaced left turn ramp to improve mobility and MoDOT conquered challenges building a retaining wall in tight vertical clearance by using a Continuous Flight Auger Tangent Pile Retaining Wall System with Soil Nails, allowing the wall the be constructed form the top down while holding back the sandy fill material during construction. Now, commuters enjoy a safer and easier to navigate interchange, made possible through MoDOT’s innovative techniques.