AIR QUALITY ASSESSMENT AT A CONGESTED URBAN INTERSECTION

Abstract

The deficient transportation system of Beirut results in significant economic losses for the city and causes severe traffic congestion in the urban areas. Proposals have been made for grade separations at some of the worst congested intersections. The major concern at these intersections is air quality which greatly depends on the geometric configuration of an intersection. The air quality impact assessment at a typical intersection is presented and potential mitigation strategies for air quality management in urban areas are addressed. Air quality measurements were conducted at representative locations to define existing pollution exposure levels. Also performed were mathematical simulations for several scenarios, both with and without grade separations, changes in vehicle mix, and level of service. By comparing simulated exposure levels with air quality standards, assessment of air quality impact was obtained.