Developing Performance Models to Evaluate the Cost-Effectiveness of Using Chemical Dust Treatments on Gravel Road

This study is part of a multiple year study conducted at the University of Wyoming to assess the effectiveness of dust suppressant treatments on gravel roads. The multiple year study was conducted to assist the Wyoming Department of Transportation and the Federal Highway Administration optimize the use of the Congestion Mitigation and Air Quality (CMAQ) funds. The CMAQ program is a federal program implemented to fund projects that contribute to air quality improvements. For a number of years, Wyoming counties have used CMAQ funds to apply chemical dust suppressant treatment to gravel roads. The state of Wyoming owns a large inventory of low volume gravel roads that connects rural Wyoming areas. The main objectives of this study were to assess the effectiveness of the CMAQ program in Wyoming, develop long-term gravel roads performance models, and conduct a life cycle cost analysis to compare the costs of treating and maintaining gravel roads.;The study utilizes field data and exploratory and statistical analyses to assess and evaluate the performance of chemical treatment on gravel roads. The results of this study will be used in developing cost effective maintenance strategies that will aid in optimizing the Wyoming asset management program. A comprehensive long-term performance model was developed to predict the service life of treatment on gravel roads. A life cycle cost analysis was conducted to compare the cost of maintaining untreated gravel roads with the cost of maintaining treated gravel roads. The results showed that higher traffic speeds, and higher percentages of fines in the soil had the highest contribution to road deterioration and increase in dust generation from treated roads. Dust treatment was found to have a service life of 1 year before dust emission rates went back to before treatment levels. The life cycle cost analysis indicated that the initial cost of applying dust suppressant treatment to gravel roads is expensive but it will increase the road service life and significantly reduce dust generation and improve air quality.