Scientific paper ID 853 : 2013/3

The interaction between the motorized traffic and the non-motorized trips or the environment raises particular matters. The traffic calming methods are useful in alleviating the adverse effects of this interaction. While some of the warning methods leave to the ethics of the drivers whether they observe or not the limitations, the physical methods are more effective in enforcing the traffic rules observance. The reverse is denoted by increasing exhaust emissions. The paper presents a method to assess the vehicles emissions on road infrastructures equipped with traffic calming elements (speed humps, turn-around etc.), based on computer traffic simulation and pollutant emission factors. The VISSIM software is used in modeling transport infrastructure, traffic rules, vehicles flows (volume, composition) and to collect output data from computer simulation. The emissions are estimated based on the average speed models proposed by European Environment Agency in the Air Pollutant Emission Inventory Guidebook. The case-study proves the excess in vehicle emissions (CO2, CO, NOx, VOC) due to the presence of the traffic calming elements. The study urges traffic engineers, urban planners and local authorities to balance the positive aspects (traffic diverting, safety increasing) with the negative ones (exhaust emissions, noise) in applying the traffic calming elements.