Evaluation of emissions and fuel consumption of Heavy-Duty Vehicles in urban areas

An investigation referred to the city of Genoa was made jointly by ICEG - University of Genoa and the Transports and Environmental Laboratory - IFSTTAR, aiming at the definition of specific information on heavy-duty vehicle (HDV) activities in urban and port zones. Circulating fleet, mileage and speed patterns were assessed, in order to evaluate pollutant emissions and energy consumption of different vehicle classes. Several issues were considered within the study. Firstly, HDV flows entering and leaving the urban area at the different highway exits and the relevant share involved in port operations were evaluated. Then, typical trips connecting the highway exits to the port gates and the relevant HDV mission profile within selected port terminals were identified, followed by an experimental campaign focused on the acquisition of instantaneous speed related to these trips and the selection of the most representative speed patterns. Finally, an instantaneous model (Passenger car and Heavy duty Emission Model, PHEM) was applied to the experimental speed profiles to estimate fuel consumption and emission factors for selected HDV classes. It was therefore possible to deepen the influence of urban trips and port activities on the environmental impact of HDV traffic flows, outlining peculiar aspects. As a further step of the study, taking into account the outcomes of previous analysis, a comparison between pollution from different fleets of heavy-duty vehicles circulating in Genoa (HDV involved in commercial and shipping activities, public transport buses, waste collection vehicles, etc.) was developed. This allowed identifying the most interesting ones for dedicated measures aiming at emissions reduction through suitable transport actions.