Transport emission modelling based on a bottom-up approach to facilitate sustainable transport planning
Anna Charly, Brian Caulfield
Abstract
• A transport emission model based on a bottom-up approach is proposed • Proposed model considers different emission, vehicle and fuel types, including EVs • The impact of electrifying longer rural trips is evaluated • An EV in a rural region could save an additional 1.2 kg of CO 2 during peak hour • Model can significantly assist in making informed policy decisions Modelling road transport emissions is critical in designing sustainable policies. Traditional emission models follow a top-down approach by distributing the emissions for a region based on the vehicle stock. This research envisions a bottom-up approach based on the link traffic volume, fleet, and emission factors to develop an improved model for link-based transport emissions. The proposed model is integrated with the National Transport Model for Ireland and considers CO 2 , NO X and PM 2.5 emissions from all vehicles and fuel types, including electric vehicles (EVs). Further, the impact of increasing EV trip share outside the major urban regions is evaluated. Analysis showed that emissions generated by a single vehicle were much higher in rural areas than urban ones. Results indicate that replacing a conventional car with an EV in rural counties could reduce up to 3.4 kg of CO 2 during a morning peak hour instead of 2.2 kg in urban areas.