Pima County and KE&G's Job Order Contract team began work on the La Cholla and Overton intersection on April 30, 2007. The project, originally slated to take 10 weeks to complete, was finished five weeks ahead of schedule on June 1st.
The La Cholla and Overton intersection is located in one of the fastest growing regions in northwest Pima County. Capacity and safety improvements were sorely needed, due to the burgeoning residential housing developments and roadway traffic of approximately 19,000 cars a day.
The intersection safety improvement project consisted of signalization of the intersection, curb and gutter installation, Right-of-Way fencing, drainage along roadways (rip rap and decomposed granite), and ADA compliant handicap ramps. In addition to raising the intersection a total of two feet to facilitate storm water run-off, crews also widened the road to accommodate dedicated right and left turn lanes and reconstructed sewer manholes.
The project enhanced the traveling public’s safety, improved the existing roadway and devised many cost-saving strategies in the process.
KE&G and the team used many innovative approaches on this complex project:
* Atypical traffic control: All traffic was routed around the outside boundaries of the intersection, allowing work in the center of the intersection to be completed with minimal disruption.
* Intersection grade design: In order to alleviate storm water pools within the intersection, KE&G proposed a change in the original design: rather than multiple lifts of asphaltic concrete to achieve a required elevation change, KE&G proposed a typical pavement cross-section of 5" of asphalt on 4" of aggregate base course. This design transformation would effectively save time and money on the intersection in the short and long term.
* Cast in place manhole process: Of the project's nine manholes requiring restructure, four were located in the center of the intersection. As the intersection was built up to the rough grade stage, cast-in-place manhole adjustments were being installed concurrently to achieve manhole heights meeting rough grade.