This synthesis will be of interest to maintenance managers, maintenance engineers, and others concerned with the implementation and evaluation of preventive maintenance strategies. Detailed information is presented on the formulation, use, and assessment of this type of maintenance strategy. Preventive maintenance strategies are viewed as a means for improving effectiveness of state highway maintenance programs. This report of the Transportation Research Board describes the preventive maintenance practices of several states, along with the rationale for these practices. It covers the history of preventive maintenance along with funding considerations, strategy development, and cost analysis. Recommendations regarding current practices and future funding schemes are also included.  The report for this topic can be purchased at https://www.trb.org/news/blurb_detail.asp?id=3404