Methodology to Select Unpaved Roads for Chemical Treatments within Budget: Case Study

Abstract

This study developed a model to select the best subset of unpaved roads for chemical treatments as dust suppressants within a limited budget. Many of the unpaved roads in the State of Wyoming receive heavy traffic loads due to the production of coal, oil and gas, and agricultural activities which result in high dust emissions. This dust can pose a significant negative impact on human health and crop yields. In 1991, congress passed the Intermodal Surface Transportation Efficiency Act and created the Congestion Mitigation and Air Quality Improvement Program, which allocates a limited budget each year to the Wyoming DOT to reduce the dust from unpaved roads. Due to the limitations within the funding, a request is required from the local governments to be submitted to the Wyoming DOT each year. From these requests, a select few receive capital to improve the dust emission with the application of suppressants on unpaved roads. In this study, a methodology was developed to select the roads for treatment that incorporated different parameters including traffic characteristics, % fines passing a #200 sieve, annual rainfall, and location relative to houses and agricultural land. An optimization formulation was developed for the selection of roads. Due to having nonconvexity, the exact solving method was implemented to identify the roads.