Urbandale Drive to Plum Drive Widening

Located in Urbandale, IA

The project involved full reconstruction and widening of the roadway from NW Urbandale Drive to Plum Drive; it was undertaken to complete another component of the transportation network associated with the Urban Loop. Completing the 100th Street interchange along with the improvements at Ryder Corner and a half interchange at Meredith Drive had improved and impacted traffic patterns in the area. Employees and customers of many local businesses were now using the 100 Street Interchange to access I80/I35. Local residents also found this access convenient. That increased usage was placing additional truck traffic on this project route. With increased traffic comes safety concerns and increased noise; residents in the immediate area have expressed concerns about these factors. An improved roadway section consisting of two traffic lanes and a continuous left turn lane was proposed to accommodate these concerns. This helped move traffic and provided a safe zone for turning motions into local neighborhoods.

Three key factors needed to be addressed with this project:

Realignment of the Meredith Drive/104th Street Intersection

From a traffic safety standpoint, one of the most urgent needs was the realignment of the Meredith Drive/104th Street intersection. The northbound and southbound left turn lanes were offset, creating a safety issue. This was corrected by shifting the northbound lanes to the west to create directly opposing left turn lanes. This design change resulted in relocating the traffic signal pole and adjusting the signal head locations on the existing mast arm to be centered on the new driving lanes. A side benefit was that more clearance was provided to the retaining wall at the SE corner of the intersection thus allowing construction of a multiuse trail on the east side of the roadway and adjacent to the sports complex.

Storm sewer system improvements

Upgrades to the storm sewer system were handled effectively and efficiently. The city wished to preserve as much of the existing storm sewer system as possible, including lateral and longitudinal runs. Careful consideration of pipe and intake capacities was required due to recently updated rainfall intensity values. Pipe sizing generally proved adequate, but many additional intakes were required. Preserving the lateral piping was relatively straightforward- removing and replacing the existing intakes and extending the pipe runs. Longitudinal pipe runs were addressed by full or partial pipe replacement with collars and new custom structures. The storm sewer improvements’ most critical aspect was the outfall to an 84’ diameter culvert just north of Meredith. The apron had been washed out due to stream degradation; the footing and pipe support needed to be replaced and then protected using class E riprap in a newly constructed stilling basin.

Phasing of the project

Project phasing was one of the most critical project components to be addressed. As with any reconstruction project, several localized neighborhoods had single access points. Those accesses were maintained using phasing splits at the entry points and split drives.. Of biggest concern was maintaining access to the sports complex south of Meredith. The complex is a heavily used facility virtually every weekend throughout a typical construction season. The location of construction staging areas and the installation of safety fences were critical to public safety using the soccer fields.