Predicting traffic-generated carbon dioxide: Concentrations in Sydney

The abilities of two line-source dispersion models to predict road-edge concentrations of carbon dioxide along several roads are tested. The comparison of the predicted CO2 concentrations from both CALINE4 and HIWAY-2 using a new power-based emissions module are compared with eight days of experimental data collected at three sites in Sydney through a recent held study carried out by the Commonwealth Scientific Industrial Research Organization (CSIRO) on behalf of the Road and Traffic Authority (RTA) in Sydney to quantify air pollution near roads and highways in Sydney. The measurements were made at locations up to 60 m downwind from the roadside and to heights 10 m above the ground; The comparison of the measured CO2 concentrations and those predicted on the basis of appropriate traffic and meteorological data shows that both CALINE4 and HIWAY-2 when used in conjunction with the new vehicle emissions module, satisfactorily estimate road-edge concentrations of CO2. As such, both the two dispersion models, CALINE4 and HIWAY-2, in conjunction with the new power-based emissions module, are potentially useful tools for highway planners.