Sustainability of transportation systems: air pollution scenarios

Sustainability is a planning perspective that accounts for economic, social and environmental aims. The transportation of people and goods represents a special and unique challenge for sustainable development. Although transportation provides many economic and social benefits, the movement of people and goods can have significant environmental consequences that can, in turn, have social and economic repercussions. Sustainable transportation calls for ensuring that the environment is considered, along with economic and social considerations, in transportation decision making. In accordance with sustainable transportation, this paper presents an overview on air-pollution problems in a complex valley, located in the middle of Italy, and then discusses current and on-going new deals for reducing transport-related air pollution. This incorporates both "how to control transport" and "how to improve air quality". For this purpose a detailed evaluation of the changes in air pollution, following new road projects, is also provided. The analysis includes a comparison of the impacts in a scenario of planned new road network and in a scenario of an actual road network. The issues to be taken into account for an individual road network planning shall include air-quality improvement, economic development and safety improvement. The dispersion of road-traffic emissions has been modelled using the Gaussian Dispersion Model AERMOD-PRIME. AERMOD is a steady-state plume-dispersion model for assessment of pollutant concentrations from a variety of sources. For this assessment, AERMOD-PRIME has been used to calculate concentrations of CO (mg/m(3)) under prevailing weather conditions.