World trends in the field of intellectualization and digitalization of all activity spheres, caused by the rapid growth of engineering and technology, have caused serious changes in the transport sector. Road transport has a negative impact on the environment, to a large extent this relates to city’s air pollution in urbanization conditions and the vehicle fleet accelerated growth. Reducing the negative vehicles impact on the environment is possible only through the development of integrated solutions for managing the transport system. Goal of this article is to study the applicability of decision support systems and simulation models to predict the possibility of reducing the negative vehicles impact on the environment. The developed simulation models for road network problem areas of the Naberezhnye Chelny city allow us to study the influence of traffic parameters on the volume of harmful substances in vehicles exhaust gases, as well as noise pollution. Using the model, it is also possible to assess the possible reduction in the degree of air pollution when converting engines public transport to natural gas fuel. Model experiments showed the adequacy of the proposed approach.