Components of a Transportation / Land Use System
A transportation / land use system can be divided in three subcategories of models:
  • Land use models are generally concerned about the spatial structure of macro and micro-economic components, which are often correlated with transportation requirements. For instance, by using a set of economic activity variables, such as population and level of consumption it becomes possible to calculate the generation and attraction of passengers and freight flows.
  • Spatial interactions models are mostly concerned about the spatial distribution of movements, a function of land use (demand) and transportation infrastructure (supply). They produce flow estimates between spatial entities, symbolized by origin-destination pairs, which can be disaggregated by nature, mode and time of the day.
  • Transportation network models are trying to evaluate how movements are allocated over a transportation network, often of several modes, notably private and public transportation. They provide traffic estimates for any given segment of a transportation network.
To provide a comprehensive modeling framework, all these models must share information to form an integrated transportation / land use model. For instance, a land use model can calculate traffic generation and attraction, which can be inputted in a spatial interaction model. The origin-destination matrix provided by a spatial interaction model can be inputted in a traffic assignment model, resulting in simulated flows on the transportation network.