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Non-Traditional Stabilization Solutions for Unsealed Roads


About 1.5 million of the 4 million miles of roads in the United States are unsurfaced. Managed by federal, state, county or city road agencies, other local authorities, the forestry and mining industries, agriculture, national park authorities, and tourism, railroad, and utility companies, these unsurfaced road networks are fundamental to the national economy, often serving as a vital link for natural resources and agricultural products to reach the paved road network. Unfortunately they often have poor riding quality with unacceptable levels of rutting, raveling, washboarding, erosion, impassability during wet weather, and dust.

Although dust is considered only as a nuisance by many practitioners, the loss of fine binding material from the road surface increases rates of gravel loss and deterioration of riding quality, resulting in increased maintenance costs. Uncontrolled dust can also create serious respiratory health concerns, with an EPA study reporting up to 50 percent of PM10 emissions and 19 percent of PM2.5 emissions in the US are attributed to dust from paved and unpaved roads including construction sites. [Rough, dusty roads have other significant, but often overlooked consequences, including increased vehicle operating costs, driver safety hazards, reduced agriculture and forestry yields adjacent to roads, reduced palatability of pasture for livestock, and transport of sediments into streams.

Using good management practices to minimize the potential economic, social, and environmental impacts of unsealed roads is especially vital, given the vast extent of the unsealed road network, both in the United States and worldwide.

The existing unsealed road management practices of most road authorities leave much to be desired, with programs for chemical stabilization and dust control largely overlooked. However, increasing concerns with regard to road safety, deteriorating air quality, adverse environmental impacts of rock quarrying and haulage, depletion of natural aggregate resources, and the increasing costs of road maintenance and gravel application have placed renewed interest on unsealed road management and preservation, with specific emphasis on chemical improvement. Hundreds of chemical products are currently in use on unsealed roads, with most designed to serve the dual purposes of road stabilization and dust control.

However, while traditional stabilization methods like cement, lime, fly ash, and bitumen are well-documented and routinely employed, there are no comprehensive guidelines for the use of newer non-traditional stabilizers. When properly selected and applied, non-traditional stabilizers can improve road performance and durability, and reduce both level of dust and rate of gravel loss. Unfortunately, no regulatory guidance is available to gauge a product’s performance in a standardized way. Moreover there is scant information available on the cost-effectiveness of non-traditional stabilizers, especially in comparison with the paving alternative.

Furthermore, although research evaluating stabilization products has been widespread, these results are scattered across a wide variety of agency reports, county records, and university publications. This lack of reliable, accessible information frequently forces road authorities to rely on a combination of vendor-supplied claims and trial and error in making unsealed road stabilization decisions.


Review state-of-the- practice regarding non-traditional road stabilization methods and technologies; identify cost-effective stabilization options and solutions based on proven research, testing and performance monitoring; document effective management, decision-making and funding processes in selecting appropriate solutions; and prepare a compendium of reliable information and resources that can be applied to optimize resources for stabilizing unsealed roads and controlling dust.

Sponsoring Committee:AKD30, Low-Volume Roads
Source Info:Standing Committees on Low Volume Roads (AFB30), and co-sponsors Stabilization of Geomaterials and Recycled Materials (AFS80), Pavement Maintenance (AHD20), and Transportation Needs of National Parks and Public Lands (ADA40).
Date Posted:03/15/2019
Date Modified:04/18/2019
Index Terms:Stabilized materials, Dust control, Unpaved roads, Gravel roads,
Cosponsoring Committees:AKG90, Stabilization of Geomaterials and Recycled Materials; AKT30, Pavement Maintenance; AEP20, Transportation Needs of National Parks and Public Lands
Maintenance and Preservation

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