Development of Holding Strategies for Deteriorated Low-Volume Roads: Introduction to Test Sections in Iowa

Heavily deteriorated low-volume roads in the United States often face the plight of insufficient maintenance funding. Funding priority is usually given to roads that are part of the National Highway System (NHS). Rural highways that have the geometry and speed limits intended for lower traffic volume are not included in the NHS and may be managed by state highway authorities, counties, or townships. Low-volume roads provide access to areas that are less populated and typically have traffic counts of less than 1,500 average daily traffic. To improve such roadways, highway agencies are interested in holding strategies that are more aggressive than preventive maintenance but not as extensive as rehabilitation. The Iowa Department of Transportation constructed test sections with 10 holding strategy treatments to aid in the development of appropriate guidelines. Holding strategy treatments use various combinations of thin surfacing technologies and base recycling and strengthening treatments for flexible pavement rehabilitation and preservation, including single- and multiple-layer chip seals, thin and ultra-thin asphalt overlays, cold in-place recycling, and full-depth reclamation. This paper summarizes the construction of the test sections and recent observations of the performance and maintenance of the treatments. On the basis of the construction costs and treatment life expectations from the literature, a draft decision table is proposed for the selection of holding strategy treatments. The decision table recommends the most cost-effective holding strategy treatment among the 10 treatments that were constructed for a specified holding period. The decision table will be validated in the future with further performance observations.