When to adopt Demand-Responsive Transport systems instead of regular public transport

Demand Responsive Transport (DRT) systems provide versatile transport operations and are capable of quickly adjusting to fluctuating passenger demand. Unlike traditional public transport (PT), which operates with fixed routes and schedules, DRTs offer flexibility in vehicle routes, fleet sizes, and schedules. This flexibility is an intrinsic characteristic of DRT systems and a key attribute in their design and associated decision-making processes. However, flexibility also presents significant design challenges, due to the multitude of potential configurations and the unique characteristics of each service area. As practice shows, the effectiveness of DRT configurations is heavily influenced by demand levels. Highly flexible operations are typically suited for low-demand areas, whereas higher demand may require reduced flexibility to maintain system efficiency. Furthermore, demand may grow to a point where the operators may question whether to continue operating as a DRT or shift to traditional regular public transport, with predefined routes and schedules, and more efficient operation. This work studies how demand levels and characteristics can be used in the decision to adopt a DRT system, instead of PT. The problem was addressed through the simulation of various demand scenarios in a virtual environment, thus comparing the performance of the different transport systems. In the scenario analysed, it was possible to identify a demand threshold where the DRT system is more efficient, while higher demand favours the fixed-route system. However, it is important to note that this threshold may be significantly influenced by the specific characteristics of the service area where the system will operate.