Public transport vehicles are involved in a high percentage of traffic accidents in intermediate cities, mainly due to speeding and lack of control over their routing. In addition, many passengers of these vehicles report poor quality of service. To try to improve this, the authors propose a system to provide a public transport vehicle tracking service with high quality regarding accessibility, safety, and comfort. They developed an ITS architecture for this type of city following a methodology, they constructed a detailed service diagram using the ITS architecture and quality requirements, and finally, they selected the adequate wireless communication technology for the service. They determined that an IoT-based system, with LoRaWAN technology and considering the developed ITS architecture, provides the service with the required characteristics. They also analyzed the use of the proposed service design in the case of an intermediate Colombian city, determining the required components, network, and budget.