Boone County’s growing transportation network

There are approximately 840 miles of roads that Boone County must maintain.

This daunting task, funded by a sales tax initiative, consumes a large percentage of the county’s budget. One difficult question to answer is how to use these funds as effectively as possible to protect our transportation network.

There are five different surface types used on Boone County roads: asphalt, concrete, gravel, chip seal over gravel and magnesium chloride gravel.

Over the last few years, Boone County’s road and bridge staff has been evaluating its roads and establishing a rating system for them. The system’s purpose is to assess the conditions of asphalt, concrete, chip seal and gravel roadways, and to identify what, if any, corrective measures are appropriate, ranging from immediate repair to routine maintenance.

Evaluation methods vary according to surface type. Rating methods have been developed for asphalt and concrete roads. A method of evaluating chip seal and gravel roads is currently being researched by the maintenance operations staff.

Asphalt roads

In the past, we would decide on which roads to repair during the first quarter of the year so that we could do prep work as early as possible. Typically this work consists of sealing cracks, cutting brush, replacing pipes and ditching.

Over time we realized that we did not allow enough time to complete the work, and that meant that we would have to include prep work in the contracted portion of the project, thereby increasing the cost of the project.

Analyzing roads with a rating system will allow county staff to effectively forecast long-term planning and budget needs. Two years ago, by using ratings of asphalt roads, staff developed a five-year pavement preservation plan. Maintenance workers now know when a planned activity will occur and can adjust their maintenance schedule and practices accordingly. For example, if a road is scheduled for an overlay next year, then that road becomes a priority on the crack seal list for this year.

Research in the pavement preservation industry indicates that every dollar spent on preservation equals five dollars saved on rehabilitation. This is why the Boone County Commission recognizes and makes a substantial investment in pavement preservation.

We are often asked why our department is working on a “good road” and not “Road XYZ.” The answer is that we are attempting to preserve the good road, and XYZ road is outside of the preservation window because it requires a more in-depth and expensive fix. Our rating system is now allowing us to identify the roads requiring a rehabilitative repair. Staff is currently researching ideas and methods to address these roads and proposing potential solutions to the Boone County Commission.

Concrete roads

Last year a concrete road repair fund was established, and a project is currently under construction on Georgetown Drive. After the project is complete, staff will monitor the performance of the concrete street and determine if any adjustments should be made to improve the program.

In rating concrete roads, staff has also identified some existing concrete streets that just require minor or spot concrete slab replacement to bring the road rating up to a good condition. The county uses a more targeted solution to these types of roads. Grace Lane — a well traveled street — received the more targeted solution of slab replacement this summer.

Gravel, chip seal over gravel and magnesium chloride gravel roads

Our staff is just beginning to rate chip seal and gravel roads. One lesson learned from the rating efforts made on the two previous types of roads is that the method used to establish a good rating system is different for every surface type.

The first step in rating roads is to develop a method for the rating system. The key to this is to determine what we want the data to answer. Our maintenance staff is currently working on these questions. Once this is done, ratings will be completed. This information can then be used to assist maintenance staff in developing a more robust and efficient maintenance program.

There has been tremendous progress in the past three years regarding the management of our roads. Improvements in our asphalt preservation program has yielded some significant results, including cheaper per-unit preservation costs, increased prep time for our maintenance forces and improved timing of project.