WP4 focuses on obtaining a better understanding of delays of public transport (WP4a). For railways this can partly build on work on understanding robustness from the DSF RobustRailS project. IPTOP builds on this in a PhD-study, which will estimate and calibrate simulation models that can predict the delay distributions from a given railway schedule. Several methods and software products exist for simulation of railway schedules, however, the focus in IPTOP is to understand and estimate the statistical input distributions in order to improve such models (Cerreto, 2011).
A parallel activity will look at predicting delay distributions for bus schedules with a link to road oriented projects at DTU Transport. The delay simulation models will provide the supply input to the passenger model (WP3a, Nielsen et al, 2008) as well as evaluating (updating) the object function of the optimisation model (WP5).