IH 35 at Shiloh Road Improvements and Bridge Replacement

Heavily traveled IH 35, just six miles from a major international bridge, requires roadway expansion and a new bridge. The response is a complex overpass that integrates skew angles with extremely long spans that exceed standard design criteria. The project includes replacement of the existing IH 35 underpass of the Union Pacific Railroad with an overpass, addition of northbound and southbound frontage roads with at-grade railroad crossings, provision of turnarounds, and bridge replacement and new bridges at Shiloh Road.

The Walter P Moore bridge team used OpenBridge Modeler to build a 3D model that can be rotated to view from any angle, while the roadway team used an OpenRoads model. We developed a unique bridge rail design to protect semi-trucks by redirecting them without damaging the rail. The adjusted super elevation is not banked as steeply as before and allows the reverse curve to be friendlier to trucks. Temperature changes in steel combined with complex geometry, forced design of a special joint to handle the movement. We met with manufacturers to develop specifications for a special swivel modular joint.

Our approach focused on a low impact design by burying the railroad bridge, reducing costs and impervious cover of the ground. Open drainage ditches avoid the use of reinforced concrete pipes, allow increased absorption of rain, and avoid filtration of pollutants. Natural vegetation and bioswales slow down the release flow. Our specialists coordinated design with teams on connecting projects and developed plans for drainage systems, construction phasing, traffic control, and ROW acquisition.

Our team coordinated the design with adjacent projects under construction, and developed plans for drainage systems, construction phasing, traffic control, and right-of-way acquisition. The Walter P Moore design delivers a huge improvement in roadway safety, increases traffic capacity, and provides improved vertical clearance on the bridge.