Urban Computing collects heterogeneous data from diverse sources,integrates it and analyzes it to deal with the challenges faced by the Urban cities. Due to rapid urbanization it has emerged as an important research area. Urban computing connects unobtrusive and ubiquitous sensing technologies, advanced data management and analytics models,and novel visualization methods, to create win-win-win solutions that improve urban environment, human life quality, and city operation systems. It has various areas of application include cultural archiving, energy consumption, health, social interaction, transportation and environment. In this paper we discuss various key challenges and issues related to traffic management in urban cities.