Freight Distribution in Urban Area: Estimating the Impact of Commercial Vehicles on Traffic Congestion

Urban freight transport plays an important role in the sustainability of the cities, as it is the last-leg of the supply chain which connect the production activities, generally located outside, to both commercial activities and final consumers, located inside the city. The problem that arises is related to the estimation of impact that the commercial vehicles determines on traffic congestion, and more generally on the liveability of urban areas. Current methods use the passenger car equivalent coefficients to convert heterogeneous traffic into homogeneous one in which it is assumed that only cars are travelling, according to different criteria based on road and vehicles characteristics, and traffic composition. The paper introduces a criterion of conversion of commercial vehicles based on the freight capacity, according to the potential impact of the vehicle when executing the freight delivery operations inside urban areas. This problem is further amplified in urban areas where there is a lack of material and immaterial infrastructures able to support city logistics operations, as in the case study examined.