An integrated urban systems model with GIS

The ceaselessly increasing number of trips on urban highways and major arterial roads have caused serious congestion and air pollution problems. Thus many transportation agencies have persevered in their efforts not only to alleviate such problems, but also to minimize social costs. However, the complex nature of such problems has strongly hindered transportation agencies’ ability to consider an integrated framework, which combines land use and transportation planning. Both urban travel and land use are too strongly interrelated to be separately considered. The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) has stipulated that transportation planning be a systems approach considering both environment and performance concurrently, requiring that planners consider transportation planning in conjunction with land use planning. ISTEA necessitates a more comprehensive, multimodal, systems management approach to transportation planning. As a result, many metropolitan planning organizations have considered both land use and development in their long term transportation planning as well as short term transportation improvement programs (FHWA, 1998; Kaiser et al., 1995). For many years, transportation planners have attempted to develop integrated land use-transportation models in various modeling frameworks. However, there have been few successful implementations of the integrated, operational land use-transportation model due to some critical problems, such as lack of necessary transportation network and socioeconomic data, labor-intensive data operation, and difficult model formulation. In order to overcome such problems, this study has explored GIS technologies, which can possibly support the development of an integrated, operational land use-transportation model.