Article Integration of land use, land cover, transportation, and environmental impact models: Expanding scenario analysis with multiple modules Harutyun Shahumyan University of Maryland, USA Rolf Moeckel Technical University Munich, Germany Abstract It is an expensive and time-consuming task to develop a new model. Furthermore, a single model often cannot provide answers required for complex decision making based on multiple criteria. Coupling models are often applied to make use of existing models and analyze complex policy questions. This paper provides an overview of possible model integration approaches, briefly explains the modules that were integrated in a particular application, and focuses on the integration methods applied in this research. While the initial attempt was to integrate all models as tightly as possible, the authors developed a much more agile integration approach that allows adding and replacing individual modules easily. Python wrappers were developed to loosely couple land use, land cover, transportation, and emission models developed in different environments. ArcGIS Model Builder was used to provide a graphical user interface and to present the models’ workflow. The suggested approach is especially efficient when the models are developed in different programming languages, their source codes are not available, or the licensing restrictions make other coupling approaches impractical. Keywords Model integration, coupling, land use, transportation, emission, Geographic Information System (GIS) Introduction Policy makers are facing challenges of managing multifaceted urban and environmental systems influenced by global factors—such as population growth, migration, recession, Corresponding author: Harutyun Shahumyan, University of Maryland, 1112J Preinkert Field House, College Park, MD 20742, USA. Email: shahumyan@hotmail.com Environment and Planning B: Planning and Design 0(0) 1–22 ! The Author(s) 2016 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0265813516647062 epb.sagepub.com