Reliable journey planning in multimodal networks under travel time uncertainty

Efficient and smart journey recommendations, such as optimised departure time, significantly enhance travel reliability in the dynamic environment of multimodal and integrated transportation systems. These recommendations help meet users’ personalised needs by improving punctuality and reducing journey time. However, inappropriate departure timing in a time-dependent traffic environment can cause longer travel time, delays and deviations from planned arrivals. A model is developed to optimise departure times at the journey’s start, considering the desired arrival time at the destination. The model aims to minimise total cost, including in-transit cost, waiting cost and early/late arrival penalties. A case study using a multimodal transport system (walking, bus and subway) in Xi’an, China, explored how factors such as punctuality preference, travel time and value of time impact on departure time choices. Results indicate that optimised departure times can significantly reduce total cost while improving the probability of on-time arrivals, especially in congested urban settings.