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Jun 21

Road Construction Explained

Posted on June 21, 2022 at 9:20 AM by Britt Nielsen

Road Closed sign

Each year, the Linn County Secondary Road Department completes a number of large construction projects, but how do we decide what projects to do? Where does the funding come from? Let us tell you.

Where does the funding come from?

Residents often ask, how much does the Secondary Road Department receive from property taxes? Property taxes paid for a property assessed at $200,000 in rural Linn County is approximately $3,000, of which $287 (10%) of that goes to the Secondary Road Department. For perspective, $287 pays for just over one load of rock. The Board of Supervisors transfers the maximum amount allowed by state law to the Secondary Road Department through property taxes. These transfers are known as the General Fund Transfer and Rural Services Fund Transfer. 

Additional revenue sources for the Secondary Road Department include dollars from the Road Use Tax Fund, Local Option Sales Tax, Regional Planning Affiliation for Region 10, Farm-to-Market, and the Highway Bridge Program. Occasionally, certain funding sources can only go toward certain projects, which factors in to our project prioritization process.

How do we decide what projects to do?

Now that we have identified funding sources for construction projects, which is approximately 42% of all Secondary Road Department funding, how do we decide what projects to do? We look at the data!

Each year, per Iowa code, the Linn County Secondary Road Department presents to the Board of Supervisors an updated 5-year plan laying future construction and maintenance projects to improve the County’s secondary road infrastructure.

When deciding how to prioritize projects, the Secondary Road Department considers multiple sets of data such as traffic counts, Pavement Condition Index (PCI) numbers, and bridge ratings. Traffic counts are a measure of how many vehicles per day (vpd) drive the road. If resources are limited, priority is given to roads with higher traffic counts as they serve more drivers. 

Every two years, the Iowa Department of Transportation drives all hard surface roads in Linn County with a special van designed to measure information such as road smoothness, cracks, faulting, etc. This information is used to determine an overall numerical rating (0-100) on each road segment to show its condition. This number is the Pavement Condition Index (PCI), which is used to determine which roads warrant maintenance, repair, or repaving. 

In addition to traffic counts and PCI numbers, all 257 Linn County bridges are inspected every two years by an independent consultant. Multiple aspects of each bridge are inspected, but the three main bridge components (deck, superstructure, and substructure) are evaluated and given a rating from 0-10. Scores of 8-10 is ‘Good’, 5-7 is ‘Fair’ and 0-4 is ‘Poor’. The entire bridge’s condition is considered Good, Fair, or Poor based on the lowest score of any of the three main components. So if a bridge scores Good or Fair in two of the three areas and Poor in a third area, the bridge’s entire rating will be Poor.

The inspector also evaluates the bridges for load capacity. The bridge’s condition, design, and weight of legal vehicles determines if any bridge needs to have a load limit posted. The Secondary Road Department uses these inspection reports to determine which bridges warrant maintenance, repair, or repaving.  

In summary, the data is used to be as objective and as consistent as possible when determining project priority, but judgment can still be a factor. Other things taken into account when creating project plans include funding availability, mobility, system connectivity, and truck traffic. 

2022 Secondary Roads Construction Projects

Linn County Secondary Road Department has 18 projects planned for the 2022 construction season. Seven of those projects include hard closure:

  • Hollenbeck Road Bridge – this bridge replacement project started May 23 and will take 3-4 months to complete.
  • Bear Creek Road – this reconstruction and concrete paving project started June 6 and will take three months to complete.
  • Bertram Road Bridge – this bridge project is expected to start in November. 
  • Edgerly Road Bridge - this bridge project is expected to start in September.
  • Lefebure Road Paving – this concrete overlay will start in June.
  • Jordan’s Grove Road – this project to widen the road will begin mid-summer.
  • Sawyer Road Box Culvert– this culvert replacement project will begin late summer.

In addition to these construction projects, the department also completes multiple maintenance projects each season including roadside mowing, dust control application, rock road grading and improvements, sign replacement, and more.

Learn more about the Secondary Road Department and sign up for project notifications.