Increase of population and activities in towns, among other things, leads to traffic and transport problems. Discrepancy between citizen's needs and existing economy and functionality of public traffic systems leads to traffic jam, but also to negative effects to environment. In that situation private vehicle is not the best solution, because it emits great number of pollutants in the environment. As a product of the technological improvement in rail industry there have been created light railway systems, as one of the most flexible form of public transport. This paper represents importance of light railway systems for urban development, its positive effects on environment, as plans and projects related with light railway systems introduction in Belgrade.