Approach for urban driving rain index by using climatological data recorded at suburban meteorological station

A methodology is developed to derive the degree of driving rain exposure in an urban area based on meteorological data recorded at a suburban climatological station. A relationship between driving rain indices in an urban and a suburban area is derived in terms of attenuation coefficient in the direction φ (Cφ). The method is verified for the Montreal region. A range of Cφ values have been proposed to facilitate the computation of the driving rain index in an urban location.