Resumen
According to the reports of WHO, air quality is deteriorating year after year. This phenomenon mainly originates in energy, industrial and transport activities of countries and cities, becoming the direct cause of global problems associated with the greenhouse effect, acid rains or the ozone hole. The fastest growing metropolitan areas are also the most contaminated ones where the protection of people, animals and plants poses a serious challenge. Although the analysis of recent years clearly indicates that air quality in Polish cities is getting better, the indicators of pollution are still too high. According to the norms for gas and dust, the most polluted places in Poland are the Cracow metropolitan area and Upper Silesia. The significance of transport is conditioned by the fact that, in Europe, transport is responsible for more than half of total emissions of nitrogen oxide and nearly half of carbon dioxide. Nationally, the level of emissions of these gases amounts to about one third. In addition, the significant problems of road transport are numerous traffic accidents and impediments in the flow of traffic, observed especially in urban areas. The aim of the paper was to evaluate the impact of transport-related pollution on the functioning of urban areas. The obtained results will allow for the review of the most effective solutions which provide guidelines for development for smaller cities towards the environmental protection and optimization of the level and type of transport to reduce the phenomenon of congestion.