Tuesday, 16 January 2007: 2:00 PM
The effects of residual chemical on the road during blowing/drifting snow events
216AB (Henry B. Gonzalez Convention Center)
Anti-icing methods have become an effective way for winter maintenance personnel to maintain optimal driver mobility and safety. During winter weather the amount of snow and ice present, along with temperature, wind and radiation, play an important role in determining whether chemicals are applied and, if so, the types and amounts of chemicals used. In wind-exposed locations, blowing snow is one of the most significant producers of ice on the road. This often results in uncertainties in the total amount of snow mass deposited on the road surface and often is not considered in pavement condition models. Blowing snow also affects the energy balance of the roadway which can hinder model accuracy. Further, blowing snow often becomes more significant during the latter part of a winter weather event. Residual chemical from an anti-icing or deicing effort early in the storm may result in the capture of blowing snow and lead to ice formation well after precipitation has ended. Understanding the effects blowing snow has on a road surface containing residual chemical can improve the capabilities of road condition models and thus aid in the maintenance action decision making process.
This paper presents results of tests conducted to determine the amount of snow mass deposited on a road surface during several blowing snow events. The amounts of snow mass measured during the events are compared to the blowing snow prediction system. Variables investigated include chemical applications made to the road, pavement condition, pavement temperature, extent of blowing snow and atmospheric conditions throughout the weather events. Preliminary comparisons between the storm events will be investigated and presented. The impact of the blowing snow on altering the road friction will also be presented.