Winter road maintenance is expensive, especially in northern U.S. and Canadian cities. Freezing rain and snow create hazardous driving conditions, resulting in an increase of road collisions, as well as longer travel time and reduced highway capacity. In the United States alone, state and local agencies spend more than $2 billion a year on winter weather maintenance operations and millions more repairing weather-related damage to roadways. Traditional US winter road treatment includes deicing (a combination of salt and sand applied to roadways after fresh snow). The use of anti-icing chemicals prior to snowstorms is frequently used and appears effective but remains controversial due to the environmental impacts and limited verification that it actually improves road conditions. Canada has had limited consistency in their responses to inclement weather, so it has been difficult to identify which solutions are most effective in improving pavement friction. Systematic collection of friction data would go a long way toward monitoring conditions by jurisdiction and better understanding the benefits of winter road maintenance programs.
In a new study, “Factors Influencing Pavement Friction during Snowstorms,” researchers Ahmed , Karim El-Basyouny, and Tae J. Kwon use friction and maintenance operations data, as well as historical weather records, to quantify and evaluate the factors that influence pavement friction on urban roads during snowstorms. The team looked at the frequency of friction testing, the amount of information collected on material usage and operation start and end times, and what road types have been included in previous maintenance programs to create a model to predict and improve road surface conditions during storms of varying strengths. Learn more about how their research can be applied and how it can assist road authorities with making informed decisions in the Journal of Cold Regions Engineering at https://doi.org/10.1061/JCRGEI.CRENG-671. The abstract is below.
Operating an effective winter road maintenance program is a necessity for cities that face severe winter seasons. Snowstorms leave roads in a slippery surface condition that disrupts traffic flows and compromises drivers’ safety. Decision-makers use a variety of tools to control snow and ice on the roads, which include applying anti-icing chemicals before snowstorms, applying deicing substances on fresh snow, and clearing snow off the roads using snowplows. However, the influence of these tools on improving the overall road surface conditions has not been investigated. In this study, a location-specific and event-based framework was utilized to understand the impact of the different weather variables as well as maintenance operations on the variability of the pavement friction coefficients during snowstorms in urban environments. Using multilinear regression and ordinary least squares, friction coefficient models were calibrated. The final model was found to be a good fit for the data (R2 = 0.723). The model showed that the total precipitation during snowstorms, extremely low temperatures, and the potential for black ice formation worsen pavement friction significantly. On the other hand, plowing operations, the application of anti-icing chemicals before snowstorms, and frequent deicing operations all have a statistically significant impact on improving pavement friction. The model presented in this paper can be used to predict pavement friction on urban arterial and collector roads during snowstorms of different magnitudes, which could help the authorities in predicting the road surface conditions during forecasted snowstorms and deciding on the best course of action under these conditions.
Apply these findings by reviewing the paper in full in the ASCE Library: https://doi.org/10.1061/JCRGEI.CRENG-671.