With the rapidly increasing population growth and urbanization, exhaust gases from the increasing number of motor vehicles are one of the major factors of air pollution. To encourage people for using public transport alternatives and improve public transportation buses by minimizing their harmful effects on environment, significantly reduce the risk of public health. In this paper, bus alternatives for public transportation are evaluated with respect to environmental risks. For this aim, a Multi Criteria Decision Making (MCDM) approach based on type-2 fuzzy sets is considered to manage qualitative and quantitative criteria with uncertainties. The proposed fuzzy approach is applied in a real case study for Istanbul. © 2013 Taylor & Francis Group.