Effective Pavement Marking Practices for Sealcoat and Hot-Mix Asphalt Pavements

This report describes the tasks of research conducted to identify effective pavement marking practices for sealcoat and hot-mix asphalt (HMAC) pavements in Texas. The researchers reviewed literature, determined current Texas Department of Transportation (Tx DOT) and alternative pavement marking practices, and evaluated various pavement marking treatments in the field. The researchers identified few shortcomings related to pavement marking practices on HMAC pavement surfaces. However, for sealcoat pavement surfaces, numerous opportunities for improving pavement marking quality were identified. Based on the research findings, numerous recommendations were developed, which pertain to thermoplastic application on sealcoat and HMAC, waterbased paint application on sealcoat, sealcoat aggregates, surface glass beads, and field inspection. The recommendations include: ¿ Apply thermoplastic at a minimum thickness of 100 mil for all longitudinal pavement markings on new sealcoat when no other durable marking exists. ¿ Apply thermoplastic at a maximum thickness of 90 mil for all longitudinal pavement markings on HMAC when no other durable marking exists. ¿ Waterbased paint may be used on a new sealcoat surface in either of the following situations: ¿ as temporary pavement marking for up to six months, or ¿ as surface primer prior to thermoplastic application.