Modelling particle emissions from traffic flows at a freeway in Brisbane, Australia

The health risks of exposure to submicrometer particles (those with an aero dynamic diameter equal to or less than I tm) from vehicle exhaust, have led to a need to develop new models to predict likely levels of emissions from traffic flows. The lack of vehicle emissions factors for PM, has been a li miting factor to-date. Researchers in Australia have been looking for a sim ple technique to predict levels of submicrometer particles contributed by t raffic flows at the roadway. Work has focussed on examining the relationshi p between submicrometer particle number concentrations and size distributio ns in relation to traffic volume, fleet composition, congestion, fuel usage and meteorological conditions. A technique has been developed to predict a mbient submicrometer particle concentrations from traffic flows at a freewa y site with up to 75% accuracy. (C) 2001 Elsevier Science Ltd. All rights r eserved.