If we want to understand how perturbations spread across a multi-modal public transportation system, we have to include passenger flows into the model and the analysis. Indeed, in general no two different lines in such a system are physically connected directly, or share tracks or other resources. Rather, they are connected by passengers changing lines and thus transmit perturbations from one l...

The primary objective of the National Airspace System (NAS) is the transportation of passengers and cargo. It is no surprise, therefore, that passenger trip time performance is positively correlated with passenger satisfaction, airfare elasticity, and airline profits. Regulatory consumer information available to airline passengers provides measures of trip performance using only flight data (an...