Why does the Highway Department sometimes salt instead of plow or plow instead of salt?

Multiple factors influence decisions made to reduce winter weather hazards. Current air temperatures, predicted air temperatures, time of day and precipitation type are all important considerations when determining an appropriate response. In some circumstances, plowing alone is most effective at addressing potential hazards. In other instances, such as cold pavement with dry and blowing snow for example, application of salt could be problematic by allowing moisture to accumulate and possibly freeze on the otherwise dry pavement. Each case is specific to the weather conditions at hand and addressed accordingly.