The report is an interim report for the first phase of an ongoing project entitled 'Effectiveness and Environmental Impact of Road Dust Suppressants' on the cooperative research of Colorado State University and the Larimer County Department of Roads and Bridges. The research was initiated in the summer of 1992 and will be completed by June 1994. The original project was extended due to the inability to collect dependable quantitative water quality and dust data in the first several months of the project. Although preliminary in nature, the research results indicate that: 1) road suppressants have an impact on the water quality concentrations of runoff from the treated road surfaces; 2) road dust production increases linearly with vehicle speed; 3) the lignin based suppressants appeared to perform better than the calcium chloride and magnesium chloride based suppressants; and 4) the measuring device, the Colorado State University Dustometer, developed in the research is a precise research tool which can be used in future dust studies, out-performing easily the stationary bucket method for collecting dust samples.