This paper examines how Addis Ababaâ€™s public transport conditions compare in terms of sustainability before and after the introduction of a proposed LRT system. The system was proposed in order to improve the infrastructure for commuters in the city and alleviate Economic, Social and Environmental problems within the existing system. The project has started operation since September 2015 with 70% of its finances coming from the China Exim bank and the rest from the government of Ethiopia.rnThe study tried to describe the real sustainability benefits of the urban mass transport system, especially in terms of how to quantify the determining indicators in specific and empirical terms to measure the extent of these benefits. Sustainability evaluation and enhancement can be accomplished in a scientific, reasonable and logical manner within the general planning as the beginning of improving progress toward sustainability development. Indicators such as travel time (timesaving), affordability, accessibility, employment, safety, modal shift, urban regeneration, air pollutant emissions, are used for the analysis.rnLRT system has numerous evident gains in terms of alleviating the urban mobility challenges in the city. Nevertheless, it also has shortcomings on low average speed due to close gap between the stations, short radius curves and low operating speed of the trams.rnKeywords: Light Rail Transit (LRT), Public Transport, Sustainable Transport, Sustainability indicators, Travel time, Emissions