Characteristics of heat and moisture transfer between bridge road and atmosphere caused by micro meteorology over bridge and dew freezing phenomenon

Characteristics of heat and moisture transfer between bridge road and atmosphere caused by micro meteorology over bridge is explored from not only field surveys at a bridge but also indoor experiments. Indoor experiments give a relation between dew freezing density and friction resistance of an asphalt plate. It is seen from the outdoor surveys at the bridge that the surface temperature of bridge road is apt to fall below zero and to be lower than the atmospheric temperature in the night. The temperature profiles in the pavement of bridge, obtained by the survey, agree with numerical results.