Experimental Macadam Stone Base Des Moines County, HR-175, Construction Report, 1977

In today's era of advanced methods, it is interesting that a centuries-old Roman road-building concept can be the most attractive alternative available. The need for a less expensive road base construction method is very apparent, especially to the county engineer faced with maintaining quality lower traffic volume farm-to-market roads. The revival of the Macadam stone base is one possible solution. Des Moines County believed a Macadam road had excellent possibilities for their particular needs. They proposed a research project designed to eliminate some of the unknown factors of Macadam stone base construction. It is the intent of this research project to develop standardized design procedures and serve as an aid for others in constructing a Macadam base roadway. The Iowa Department of Transportation has published special provisions for the construction of Macadam stone bases that were adopted as the guideline specifications for the research project.