The first goal for this program area is to expand research in the area of winter surface condition forecasting. Using funds from the Safe-Passage project, WTI faculty have developed a computer model that, given meteorological data from a road-weather information systems (RWIS) site or a local forecast, will predict pavement temperatures on a 30-meter grid for roads through a mountain pass. The Greater Yellowstone Regional Traveler and Weather Information System includes funding to improve the model and to expand the model to one or two more sites. New equipment required to improve and expand this modeling technique include purchase of a new computer and acquisition of a low temperature environmental chamber. The current model requires extensive computer power, and it has been determined that the purchase of an 8-processor computer with RAM upgrade would serve this need as the use of the model expands, and takes pressure off the College of Engineering computers that are currently being used. Funding for the new computer will be pooled between a National Science Foundation grant, Civil Engineering funds, and WTI funds, with $22,500 coming from WTI. An environmental chamber is being designed which will provide a means to study the influence of weather and the environment on a surface or structure under controlled conditions. The item will be put out for bid. The primary and initial utility is to be able to examine the influence of meteorological conditions on pavements in a winter scenario. The influence of temperature, solar radiation, long-wave radiation. humidity* and convection will be fully programmable so that, for example, diurnal fluctuations may be prescribed independently for each of the input variables. The chamber will also have the capability to examine the influence of a warm as well as a low temperature thermal environment, which will enhance its overall utility. (*Relative humidity can only be accurately controlled at above freezing conditions.) The influence of individual meteorological components and the interaction of these components may be examined in detail with regard to icing conditions, black ice conditions, freeze thaw conditions and many other scenarios. This is to be a highly flexible system with wide ranging utility. A system such as this will allow us to examine in a controlled fashion some of the basic principles underlying a number of winter highway safety issues. An improved first principle approach to the ongoing thermal modeling, which is which is in development will be an obvious benefit. Besides the obvious importance to surface properties of highways in the natural environment, the deterioration of highway construction materials, solar penetration and the energy balance of snow and ice on and near roadways, freeze thaw problems involved in highway breakup as well as many other studies where the meteorological conditions are important may be examined. Among other studies for which this chamber would prove useful would be the influence of thermal shock and springtime breakup on pavement, pavement deterioration due to solar radiation and the influence of snow stability related to avalanches.