The code presented here is a open sourse code which generates the classic four step model demand for tranport modelling using Quetzal a library under develpment of Python. The general structure of the fourt step model is represnted in the following figure:
The sub-models are:
- Trip generation: this estimates the total number of trips generate and attracts by every zone
- Distribution: it estimates the spatial distribution of the total number of trips per zone to the rest of the zones
- Modal split: this estimates the percentage distribution of evey mode available
- Network assignment: this sub-model assigns trips to the road network or public transport network.
Much more detail information can be found in my PhD thesis in the section of modelling.