Smart Cities are those which use technology to promote the well-being of the population, economic growth and, at the same time, improve sustainability. The application of these technologies in road transportation services has been conducted within programs known as Intelligent Transportation Systems (ITS). Vehicular Ad Hoc Networks (VANETs) are a key part of the intelligent transportation systems framework. The buses belonging to a Public Transportation System (PTS) can be considered as nodes of a kind of opportunistic data network. However, the transportation literature does not provide acceptable models for bus movements in an urban environment since they are affected by vehicular and passenger traffic conditions, lanes organization, traffic signal management, company policies, and others. This article uses the Engine for Map Matching to SUMO (EMMS), a computational tool that automatically imports the public transportation system characteristics into a simulation environment in order to study the system performance. Specifically, geolocation data from public transportation buses, in the city of Curitiba (Brazil), are used. The results obtained show that the formation of small temporary networks is possible, allowing the exchange of data between buses. However, those networks provide low throughput and packet delivery rates, as well as large routing overhead and end-to-end delay.