Introduction to modelling multimodal transit systems in an ITS context

Transit network “big data” collecting and processing and bi-directional communication between transit travellers and info centres are emerging as two factors which could improve both transit network planning and design and short-term forecasting of network states for transit operations control and traveller information provision. Several methodological issues connected to the development of models for real-time transit network simulation and forecasting of vehicle occupancy and crowding degree, for supporting such activities, are analysed in this chapter. The main issues concern real-time transit system modelling, dynamic real-time strategy-based path choice and assignment models, individual path choice modelling and, finally, estimation of OD flows and aggregate calibration of model parameters through collected data.