Guidelines for Prime Coat Usage on Low-Volume Roads (05-0348)**
Stephen Cross, Oklahoma State University
Michael David Voth, Federal Highway Administration
Pramed P Shrestha, Oklahoma State University

Prime coat has a purpose in the pavement construction process, yet many times prime is misused or eliminated during the project. While most of the time no harm appears to occur to the roadway and thus may be viewed as acceptable, technical guidance is warranted to assure appropriate usage. The objective of this study was to produce a prime coat guide publication developed for Central Federal Lands Highway Division (CFLHD) project development and field personnel to provide decision-making guidance on how to use, when to keep, and when to eliminate prime coat. The literature search, which focused on handbooks and technical reports, was conducted along with a review of agency construction specifications. A phone survey of current practice of state DOTs from the region was undertaken to provide information on current practice. Finally, a review of the potential harmful and positive environmental effects of the prime coat process, including the various bituminous products used, was undertaken. Based on the information collected, a guideline for project development and field personnel was developed. The guideline provides decision-making guidance on how to use, when to keep, and when to eliminate prime coats.