5. Road cargo transport
To make a good estimate of exhaust emissions from road vehicles it is crucial as accurate as possible to specify the vehicle and fuel used, and other conditions that influence the emission levels. Therefore NTMCalc offers the possibility to make a detailed description of these parameters for all transport modes.
NTMCalc provides fuel consumptions and pollutant emission factors for four different road vehicle types; heavy duty trucks, light duty trucks, heavy duty buses and passenger cars, where the first two are used for freight transports and the latter two are used for passenger transports. The vehicle types are further divided into sub segments representing different vehicle sizes. For all sub segments NTMCalc covers several emission standards, fuels, traffic situations and road gradients.
The weight-based load factor has a significant impact on both fuel consumption and pollutant emissions. This is of particular importance to consider for heavy duty vehicles, and therefore the NTMCalc database for heavy duty vehicles contains fuel consumption and emission factors for 100%, 50% and 0% load. The impacts on fuel consumption and emission factors to added weight are assumed to be linear from 0% to 50% load and from 50% to 100% load, respectively.
Users of NTMCalc has the possibility to specify several parameters; vehicle type, vehicle sub segment, emission standard, traffic situation, road gradient, fuel, cargo type, vehicle load capacity, cargo load factor, passenger load, fuel consumption, distance and cargo weight. The latter two parameters must be specified by the user. For all other parameters NTMCalc provides default data.
A ll emission factors and fuel consumptions for road vehicles are taken from the European road emission model HBEFA 3.1 (1). The traffic situations included in the first release of NTMCalc3.0 represent Swedish average road types as defined in HBEFA3.1.
The fuel consumption for a specific transport is calculated by multiplying the distance with the distance specific fuel consumption that corresponds to the vehicle, road type and load factor entered by the user. Pollutant emissions are calculated by multiplying the total fuel consumption with the fuel-specific emission factors in the NTMCalc database. The emissions of the fuel-related pollutants CO2 and SO2 are calculated from the total fuel consumption and the specified carbon and sulphur content of the fuel.
1) The Handbook Emission Factors for Road Transport – http://www.hbefa.net/e/