Comparative results of environmental aspects obtained by Micro and Mesoscopic approach for urban road networks

The environmental impacts related to signalized intersection are tested comparing micro and mesoscopic approach and ,also , analyzing possible scenarios that lead to decrease of vehicular emissions referring to Le Bourget area on French Region of Seine-Saint Denis. Specific emission factors for the acceleration and the queue phases have been estimated at mesoscopic level starting from the microscopic approach by ENVIVER tool. In particular pollutant concentration were compared ,changing four different traffic light cycle with two phases (especially increasing or decreasing red time). It also shows the capacity of the model to test different off-line and on-line traffic strategies in order to work both on emission and congestion problems. For some decades the air quality has received, both locally and globally, more and more attention from the scientific community and local authorities. It is well known that one of the major causes of pollution are vehicle emissions, and that they are closely related with driving style. According to studies that define vehicular emissions, it has been found that they contain a wide variety of pollutants, principally carbon monoxide and dioxide (CO and CO2), oxides of nitrogen (NOX), particulate matter (PM10) and hydrocarbons (HC) or volatile organic compounds (VOC), which have a major long-term impact on air quality