The road sector is one of the main sources of air emissions in the atmosphere during both construction and operation. The objective of the present paper is a comprehensive evaluation of the impact on air quality during the two main phases of life cycle of roads. In this case study of a motorway project, the emissions of the primary pollutants, CO, NOx, and PM10 are estimated, and the results showed that (i) CO and NOx pollutants released during both phases are comparable, while the emissions of PM10 are more significant in the construction phase; (ii) 85% of PM10 in construction is due to storage, transit on unpaved road, and crushing; (iii) the portals of the tunnel are the sites where there are higher concentrations of pollutants in operation; and (iv) the CO concentrations estimated by the dispersion model are strongly influenced by the topography.
Impact of Local Environment on Cooling Island Effect of Water Body: Case Study of Changsha, China