Report 2019RIC04 is a course on Lightly Surfaced Roads (LSR) with the stated objectives of:
-Understand Lightly Surface Road (LSR) concept
-Understand the advantages and disadvantages of LSR’s
-Know the LSR applications
-Understand keys to a successful LSR
-Be familiar with some LSR failures and ways to avoid them
-Understand the LSR treatment options
-Be familiar with some online selection tools
More than 50 percent of U.S. roadways are gravel roads, making them a vital part of our transportation system. One of the drawbacks and biggest complaints about gravel roads is the dust they produce when vehicles drive over them. Residents that live on gravel roads deal with the dust that settles on their homes, yards, and parked cars, potentially reducing their quality of life. Dust can also have adverse effects on air quality and the environment and reduce the safety for drivers due to impaired vision. To
control the dust on gravel roads, local agencies apply various dust suppressants on their roadways, mainly calcium chloride and magnesium chloride. However, many other dust suppressant options exist.
The Minnesota LRRB has developed this document, Dust Control of Aggregate Roads, A Brief Synthesis of Current Practices, to provide local agencies with a summary of research that has been completed on various dust suppressants, their effectiveness, and impacts. Results from two surveys that document dust suppressants that local agencies (within Minnesota and Iowa) use is included as well.
Representing more than half of U.S. roadways, gravel roads are a major part of the country’s road network. Dust produced by cars as they drive on unpaved roads is a major and growing complaint nationwide and among Minnesota landowners near these roads. This dust can negatively affect air quality, crop yields, quality of life and even driver safety through impaired vision.
The Local Road Research Board has sponsored several studies that have evaluated the use of locally available sand aggregates and have found that they could be successfully used in bituminous mixes, particularly on low volume roads. The success of these studies, coupled with the shortage of aggregates in certain areas, has led to the development of several specifications which allow the use of locally available aggregates and bituminous mixes. This pamphlet briefly describes the research conducted and contains a summary of the specifications currently available which allows the use of a broader range of gradations.
The Mn/DOT Standard Specification for aggregates contains several different classes of surfacing and base course aggregates. To effectively use and specify these aggregates, it is important that their performance be characterized, and guidelines for their use be established. This report will outline the properties of each aggregate class and detail the effect that the specifications have on the performance, stability, durability, and weathering of an aggregate surface course, base, and shoulder material.
