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VEHICLE EMISSIONS. UoB. OBJECTIVES. To assess the effects, in terms of pollutant quantities, of changes in: Road characteristics Traffic congestion Vehicle technology. APPLICATIONS. Network level Total emissions by transport mode Regional long term impact of pollution Project level
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OBJECTIVES • To assess the effects, in terms of pollutant quantities, of changes in: • Road characteristics • Traffic congestion • Vehicle technology
APPLICATIONS • Network level • Total emissions by transport mode • Regional long term impact of pollution • Project level • Compare levels of emissions for different investment options • Pollution impact on local areas near the project road
TYPES OF POLLUTANTS • Hydrocarbon (HC) • Carbon monoxide (CO) • Nitrous oxides (NOx) • Sulphur dioxide (SO2) • Carbon dioxide (CO2) • Particulates (Par) • Lead (Pb)
THE MODELLING • The models predict vehicle exhaust emissions as a function of: • Vehicle speed • Fuel consumption • Vehicle service life • Speeds and fuel consumption depend on both road and vehicle characteristics • Thus, enabling the analysis of changes in emissions arising from different road investment options, or major changes to the vehicle fleet using the road network
MODEL PARAMETERS • Assumes emissions at 0.5* LIFE are suitable for representing the emissions • The model parameter a2 represents the degradation of a vehicle equipped with catalytic converter • For SO2, a0 is the percentage content by weight, of sulphur in fuels (Petrol: 0.012%) • For Pb, a0 is the percentage content by weight, of lead in fuels (Petrol: 0.15%)
COMPARISON OF INVESTMENT ALTERNATIVES • The comparison of each pair of investment alternatives is based on the changes in the annual difference in the predicted quantities of emissions (by component)
OUTPUTS • Quantities of emissions • by component • by vehicle type • for each traffic flow period • Annual quantities of emissions • by component • for each investment option • Annual net quantities of emissions for each pair of investment alternatives