Air pollution is becoming a very important issue for the transportation sector, particularly car emissions in urban areas, and there is much interest in evaluating the actual level of emissions across Europe and around the World. The effects of vehicle emissions can be seen from both a human perspective and an environmental perspective. The emissions from cars can have a deadly consequence on human life, as seen with the CO emission, which has been proven to be fatal to human life in a confined space. In addition, research has shown that the exposure to fuel emissions can have a carcinogenic effect on humans. This is a huge concern for people as the amount of traffic increases globally. On the other hand, energy consumption from the transport sector in many developing countries has not been dealt with the same intensity as that of developed countries. Due to the rapidly expanding mobile populations in the developing world, the issue of low carbon development and transport needs to be urgently addressed. For these reasons, Aleppo city in the developing country of Syria was under investigation through this research in order to evaluate the traffic emissions in such a busy city and provide local government access to reliable tools that can accurately estimate the contribution of traffic related pollutant levels to local emissions inventories. In this research, COPERT, one of most commonly deployed tools has been used which makes use of bulk traffic movements and average vehicle speeds in order to estimate emissions. The combination of On-board diagnostic data extraction incorporated in all modern passenger cars and COPERT emission factors have been employed to allow for the real world vehicular activity in order to better estimate the contribution of private cars to local emissions inventories. A built-in data acquisition package has been developed in LabVIEW in order to log and save the data extracted from OBD system. This data is then analyzed to obtain driving cycles of specified routes which have been plotted so that emission factors could be obtained. Advantages of this method are that it is easy to follow, inexpensive and the results are in a good fit to the estimated values. A common method involves the use of gas analyzers which measure resultant emissions directly from the exhaust manifold. Such equipment is generally expensive, difficult to calibrate and rather bulky. However it has been used at the early stage of this research for evaluating the results obtained by the estimation method where different routes of Dublin city, time and cars have been used in order to give a preliminary case study of a standard driving cycle in the urban area of Dublin city. Good correlations between the predicted results of the modeling packages and the actual data obtained by direct measurement are still maintained. After this stage, the same method has been employed in Aleppo city in order to establish a representative tool for the local authority in identifying the air quality caused by traffic emissions. As each country has a unique driving cycle which represents the characteristics of the driving and the real amount of emissions from vehicles, individual testing is necessary for each region. Comprehensive study of the two cities with all data obtained has been done and recommendations for future work have been included.