The assessment of road traffic air pollution by means of an average emission parameter

This work proposes a simple methodology to assess pollution loads discharged by road traffic within a specific temporal and spatial domain, in the case that detailed disaggregated data about vehicle fleet composition are not available at local scale. The adopted methodology starts by defining a useful specific emission function that allows easy calculation of the total amount of pollutant emissions in a year. The function, called Yearly Average Vehicle (YAV), is representative of the annual average emission factor of a homogeneous category of vehicles. The employment of the YAV permits easy assessment of different scenarios and allows the analysis of the influence of different items that could alter the global amount of pollutant emissions released by road traffic, such as improvements of emissive characteristics of vehicles, changes in the transportation demand and variations of traffic flow path lengths. The procedure has been applied to the urban area of the Italian city of Messina, where public administration has recently adopted a measure aimed at alleviating the load of the traffic pollution inside the urban area.