Expanding Liquid Application Rate Guidance with Field Data and Practitioner Experience

Current application rate guidance for liquid deicers is limited for low to moderate temperatures (below −9.4°C, 15.0°F and −9.4°C–3.9°C, 15.0°F–25.0°F) and light snow conditions (<2.5 cm/h, 1.0 in./h; <10.2 cm, 4.0 in. in 24 h). The performance of liquid deicers has been mainly studied in laboratory environments, but findings do not directly translate to highly diverse and variable conditions experienced in the field. Thus, the objective of this study is to expand liquid application rate guidance using observed field data and practitioner experience. A survey of practice was conducted to gather agencies’ liquid application guidance and practice, and to identify sites for field data collection. Data collection consisted of route information and field data, in terms of weather, roadway conditions, materials, application rates, and performance measures during storms. Fourteen agencies from six states submitted data for 22 routes, resulting in field data for 167 winter storms. Commonly used application rates were identified and shared with 12 practitioners who have extensive experience in using liquid applications. Practitioners provided feedback, validated observed application rates, recommended adjustments, and raised awareness about specific conditions. The results of this study are given in tables, with application rate guidance for different liquid applications by pavement temperature range, pavement temperature trend, roadway surface condition, and chemical material.