Intersection Air Pollution Emission Prediction Using Software Hyroad: A Case Study Fatemi-Valiasr Intersection from Iran

Pollutant emission rates for constant speed conditions distinctly differ from inconstant speed conditions of vehicles. In intersections, vehicles are forced to reduce speed, change direction, and most likely, stop for a long period of time. Pollutant CO has the most emission changes in intersections because of dramatic speed change in intersections. In this investigation concentration of CO in one of most populated and residential intersections of Iran's capital have been modeled using software hyroad. Modeling practice has been done considering several parameters, with the extent of data available on each parameter, including; traffic flow, meteorological and weather characteristics, site specific characteristics and realistic characteristics of vehicles. Amount of CO concentration obtained from model has been compared to recorded amount of CO for specific period of data available, reliability of model to predict the actual concentration of CO in this intersection has been assessed. Results shows that predicted amounts are less than actual site amounts but there is some apparent similarity associated with the change patterns of concentration, i.e. the highest and lowest concentration levels occur in the same time but with higher amounts for predicted amounts in all times.