Carbon monoxide modeling from transportation sources

Street canyon module and gaussian line source module of a regional-scale di spersion model Indic Airviro were used to simulate ambient carbon monoxide (CO) concentrations due to traffic flow at two roadside monitoring location s in Singapore. The fleet average emission factors for each vehicle categor y was estimated from US EPA MOBILE 5 A guidelines as a function of speed, v ehicle deterioration rates and model years. 1-h CO concentrations and worst case 8-h levels have been simulated and compared with measured readings. T his study used model-simulated rooftop concentration levels from non-locali zed sources as background levels at the two sites. The resulting CO concent rations correlate well with actual measured levels and provide a unique app roach to predict the impact of CO from transportation. (C) 2001 Published b y Elsevier Science Ltd.