Iowa Highway 196, Sac County, IA
Contractor: Cedar Valley Corp., LLC
Owner/Engineer: Iowa Department of Transportation
This nearly 10-mile project involved the removal of 135,000 SY of existing pavement, completion of 900,000 CY of earthwork, and placement of almost 109,000 tons of base and shoulder aggregates. The contractor, Cedar Valley Corp., paved almost 200,000 square yards of detour, mainline, and shoulder paving on the project.
The existing pavement was originally placed in 1938 and had received at least four asphalt overlays in its history. This project ran from the intersection of Highway US 71/175 on the south end, north to newly constructed US Highway 20. The Iowa DOT chose to rebuild Highway 196 and then relocate US Highway 71 from its current location in to best use the 10 miles of new US Highway 20.
The contract period was stated to be 255 calendar days with goal of opening to traffic by the day before Thanksgiving, but it was an especially wet year in Sac County. Almost 40 inches of rain hit the area, more than 9 in. more than normal. In the key Iowa construction month of August, the job was hit with 9 in. inches of rain, 6 in. of which fell in one day alone. Also, it rained on 40 percent of the days, spanning from June through September.
Two bridges were also constructed on this project. The new earth berms each had assigned settlement periods, but wet weather severely delayed completion of the berms, and the saturated soil conditions impacted the rate of settlement.
The prime contractor first scheduled the paving to start on August 3, but as the job progressed, the start date slid to September 20, again to October 5, and finally to October 12. When paving started, the contractor was able to continue for five days per week over five weeks. However, when mid-November arrived, Cedar Valley caught up with the prime contractor’s grading and base operation, so the chances of opening Highway 196 to traffic during the calendar year was looking pretty bleak.
As cold weather arrived, Iowa DOT officials expressed concerns about leaving a potentially dangerous 12-mi. detour in-place during inclement weather, mainly because it included three four-way stops and a very sharp curve on the south end of the project.
Therefore, out of concern for the safety and convenience of the traveling public, the DOT allowed a defined amount of “emergency/critical” operations to ensure the mainline of Highway 196 was opened in the winter.
All parties involved realized and agreed that this meant the roadway would need to be closed down again the following spring to complete the project. The contractor developed a plan that outlined the extra measures and expenses needed in order to make sure Highway 196 was opened to traffic in the late fall. Snow was falling as the last few days of paving were executed, but exceptional planning and execution allowed Cedar Valley to pour the two outside 14-ft. wide lanes and the 16-foot median on the south end of the project, effectively closing the detour until spring.
On the following April 4, work started up again and traffic was rerouted and placed back on to the established project detour so CVC could complete the remaining 16 miles of paved shoulders, along with a couple of paved driveways. The concrete road work was completed on April 25.
The project also included matching two newly built concrete bridges and approach pavements. Stopping the paving operation at these locations and passing over the bridges impacted smoothness in these sections. The bridge approaches, CD baskets, intakes, maintaining the many access restraints, and the extremely wet job conditions and haul roads all had the potential to negatively impact CVC’s ability to attain the maximum pavement smoothness incentive. Even so, because of preplanning and expertise on the grade, the contractor achieved almost 71 percent of the maximum zero band smoothness incentive on the mainline paving, thereby earning $111,050.
Cedar Valley used Shilstone principles to design an optimized concrete mixture, which enabled the contractor to earn the maximum mixture bonus of $121,857, as allowed by IDOT specifications. However, the money was returned to the citizens of Iowa in the bid.
In spite of the many challenges and the extraordinary steps needed to battle the weather and meet the schedule, Cedar Valley had no injuries or recordable vehicular accidents after 35,500 man-hours.
According to CVC, the best public relations a contractor can do is to get in, build the job, and get out as quickly as possible. In spite of very wet weather and other challenges, the Cedar Valley lived up to their goal by successfully battling the elements, working through the winter, and doing everything possible to meet the schedule.