Yakima County Road Maintenance conducts a visual survey and assigns a dust sensitive score to road segments every 2 years. This scoring is based on a variety of factors. Number of Homes per mile, within 300 feet of the roadway, Dust sensitive Crops per shoulder mile, within 300 feet of the roadway, Sensitive receptors (schools, gathering places, daycares, etc.) Average Daily Traffic, Posted Speed Limit, Accident Records, and land values. The number of miles we can shoot within a program year is largely dictated by the current material bid price. Material is roughly 80% of the per mile cost. If you did not receive dust abatement it is usually due to the score of your road being below the threshold of accumulative miles, we can treat, under the current year’s budget.