Today, one of the most important environmental problems in urban areas is air pollution. Road traffic is one of the main sources of pollution in cities. Besides, vehicular emissions are released in close proximity to population, increasing the adverse health effects. However, existing techniques to assess this source of pollution are not always accurate. It is essential to develop methodologies to reduce these uncertainties to manage air quality more effectively. In this work we present new methods to estimate and evaluate road traffic emissions. The developed methods were tested in a city from the developing world, in such cities road traffic emissions are highly uncertain and existing methods to estimate these emissions are expensive and difficult to afford. This research focuses on the study of Volatile Organic Compounds (VOCs), a family of pollutants that have not been sufficiently studied in the urban air quality. All the techniques presented in this work offer several advantages. Data obtained serve for different purposes at the same time and their use can provide valuable information for urban air quality assessment.