Degree Name

Doctor of Philosophy


Department of Civil and Mining Engineering


In this study emissions of carbon dioxide (CO2, carbon monoxide (CO, hydrocarbons (HC) and nitrogen oxides (NOx) from vehicles are modelled by considering the instantaneous power generated by each vehicle and modifying the expressions developed by Post et al, (1981). The emissions from both spark ignition (SI) and diesel vehicles have been included.

The model was used to estimate fuel consumption and emissions over a standard driving cycle. When used for spark ignition vehicles over a driving cycle, the influence of cold starts was quantified and allowance was made, in the case of equipped vehicles, for catalyst warm-up and for variations in catalyst efficiency.

The model was validated against fuel consumption and emissions data obtained using ADR27 and ADR37 tests, and also against detailed, high time resolution analysis of ADR27 tests carried out by the Victorian EPA.

The emissions model was used in conjunction with two pollution dispersion models viz: HIWAY and CALINE to compare predicted concentrations with an experimental dataset consisting of measurements of the pollutants of CO2, CO, HC, and NOx, and were made under a variety of traffic and meteorological conditions. The measurements were made at locations up to 60 metres downwind from the roadside and to heights of 10m above the ground. A video camera was used to record the traffic flow, speed and type (classified simply as domestic, light or heavy commercial).

The emission rates of CO, HC, and NOx (at slope 0°) for spark ignition and diesel vehicles produced by the power-based emissions model were found to be similar to those produced by the California EPA, EMFAC7, emissions model.