Facilitating Bus Fleets Emissions Assessment

Environmental issues are an imperative concern for bus companies. But, when it comes to estimating pollutant emissions, problems arise, typically: the underestimation of the local fleet potential in producing pollution (especially in case of small fleets); and the reluctance to estimate that when the fleet is composed by a not negligible amount of old-generation vehicles. To this end, an integrated emission-estimation model for bus fleets is developed and described in the paper, with the research goal to facilitate the emissions calculation task for transit operators. The procedure is embedded in a successfully-implemented software for the management and maintenance of bus fleets. The model moves from well-known assessment methods (namely COPERT and IVE) but addresses issues like long-protracted mileage and age of vehicles which make it especially useful when 'old' fleets' emissions are to be assessed. A case study, in a middle-size city in Italy, is also described to highlight the model development and results.