Removal of ice and snow from road surfaces is a critical task in the northern tier states of the United States, including Illinois. Highways with high levels of traffic are expected to be cleared of snow and ice quickly after each snow storm for maintaining the efficiency of the highway system and for safety issues. Studies have shown that accident occurrence and severity both increase with the start of a snow storm. Proper removal of ice and snow can improve road safety by maintaining higher friction levels of the pavement surface. To improve plowing operations and make them more efficient (perform at higher level), it is necessary to develop a method to measure such efficiency. It is desired that such method be easy to use, reliable, and provide repeatable results. Several performance measures exist in the literature–some purely theoretical and some in use. Also, even within the same agencies, some measures are monitored continuously (friction), some are per storm, and some are per season. Other intervals may include week by week or month by month. Research by the Iowa Department of Transportation showed that plowing load can be used as a measure of ice plow performance. Those studies showed that the horizontal scraping forces are directly related to the amount of ice scrapped; however, that is not the case for snow plowing. The most common performance measures for winter maintenance during and after a storm, among many others, are the following: - Bare pavement regain time; - Friction (skid resistance); - Reduction of crashes; - Duration and frequency of closures; - Customer satisfaction; and - Visual precipitation of roadway surface To establish uniform performance measures, information related to the weather and the pavement surface at the time of plowing operation should be collected. This information should include snow depth, temperature, surface condition (ice/no ice), and snow moisture content. Snow moisture content can be measured by evaluating the “water equivalent of the snow.” In concept, the water equivalent of snow is determined by measuring the depth of the new snow; the new snow is then melted and the resulting water amount is measured. The main objective of this study was to develop an evaluation procedure for snow and ice plow performance through field testing and finite element modeling techniques. To attain this objective, the research team conducted a comprehensive review of literature to develop a synthesis of best practices in snow and ice plowing and then developed a plow performance evaluation procedure, the main component of which is a plow instrumentation and field data collection strategy. Subsequently, an Illinois Department of Transportation (IDOT) snow and ice removal truck was instrumented to measure stresses at a number of locations on the front and underbody plows and the front plow carrying structure. Data were collected from snow and ice storms that occurred in the Peoria, Illinois, area between November 2011 and February 2014. The research team also developed a finite element model of the plows and carried out interviews with snow and ice removal professionals from around the country to identify best practices in snow and ice control. This report describes the approach that was used by the research team to achieve project objectives and presents the findings of the research. The report is organized into six chapters, including this introduction. The second chapter presents a comprehensive review of literature of snow and ice plow studies, and it is followed by a survey and synthesis of best practices in snow and ice removal and control. The fourth and fifth chapters describe the field testing effort and the finite element modeling of the plows, respectively. The last chapter contains the conclusions and recommendations from the project. The phenomenal amount of experimental data that were collected during the last few months of this project provided the team with valuable information that can be used to better understand plow behavior. However, the short time between the most recent snow storms and the time this report was prepared made it difficult to consider the data and incorporate them in the analyses. The research team will continue working with the collected data for the remainder of the project and will publish any possible new findings in appropriate venues. (Author/publisher)
Samenvatting