Grimes Pavement Management Plan

Challenge: The City of Grimes is a growing suburb in the Des Moines metropolitan area. Even though much of the City’s roads are recent construction, there was an older core to the street network that is starting to need maintenance and rehabilitation.

The City maintains approximately 66 miles of roads, and of all urban areas in the state, the City of Grimes has one of the highest average conditions, based on the Iowa Pavement Management Program’s (IPMP) condition assessment. Rapid development and some history of rehabilitation activities allowed the City to maintain a road network of high average quality, and they desire to continue providing high-quality infrastructure for their citizens.

Solution: HR Green was retained by the city to review their standards for street pavement design and construction/maintenance practices, inventory the street system, evaluate current roadway conditions provided by the Iowa Pavement Management Program (IPMP), determine major rehabilitation and reconstruction alternatives, create a Pavement Management Software dTIMS BA comprehensive model, and develop a 10-year maintenance and replacement schedule.

Using the IPMP data, existing City resources, and input from City staff, a complex pavement management model was created using the dTIMS Business AnalyticsTM software. This model was used to analyze various funding and performance-based scenarios for the Grimes capital improvement program. The findings of the investigation determined that the preferred annual construction budget would be approximately $2.65 Million for long-term sustainability. Additional emphasis was placed on the increased liabilities caused by new development and how future growth will change the projected maintenance needs.

The exploration results were then incorporated into the pavement management model, which generated an objective and computer-optimized 10-Year Capital Improvement Plan (CIP). The project list is optimized for the most effective use of available funds based on the pavement condition data and planning-level information provided by the City. Consisting of 136 Projects, the recommended program contained 21 Miles of roads or approximately one-third of the City.