Traffic-like phenomena have been observed at almost all levels of natural and manmade systems (e.g., from microscopic protein motors, data packets to macroscopic objects like cars). For these various traffic, basic and emergent phenomena, modelling methods, theoretical analysis and physical meanings are normally concerned. Inhomogeneity like bottlenecks may cause traffic congestions which are related to real traffic jams, failure of network communications, some human diseases and natural hazards. The modelling method in this book is based on totally asymmetric simple exclusion process (TASEP). TASEP has been widely used in modelling and understanding of particle dynamics in Physics, Chemistry and Biology. Mean field methods are used to analyze those mathematical models and Monte Carlo computer simulations are for verification of the models.