A longitudinal integrated forecasting environment (LIFE) for activity and travel forecasting

In the past few decades transport system simulation has experienced a radical change of modeling paradigms in which macroscopic approaches to forecasting are increasingly replaced by microscopic (disaggregate) model systems targeting the behavior of the most elementary decision-making units. An example model system called Longitudinal Integrated Forecasting Environment (LIFE) that contains a demographic simulator, a daily time allocation and travel scheduling system, and a Geographic Information System is described in more detail in this paper. In the model system, interdependence among human activities is incorporated in transportation system simulation, improving in a substantial way the quantification of mobile source emissions and the assessment of transport management and control strategies. The theoretical background of LIFE applications is first given with an example of the interaction between transport system users and transport system managers. Two model development streams are then described using examples to illustrate differences and commonalities between these two parallel approaches. The paper also describes in outline form the data and models needed to develop manmade ecosystem simulation model systems.