This paper analyzes 12 city plans that were developed based on environmental-sustainability indicators using a multi-agent model. The plans are based on three city forms and four types of city scenarios, each representing a different planning concept. The environmental indicators concern pollution from transportation, while the sustainability aspects relate to accessibility to facilities. The model supports planners in identifying the best city form considering the selected performance criteria. In this case study, a compact city form, coupled with mixed land-uses, performed best.
IntroductionThe strengths and nature of the relationships between transportation, land use, and the environment are well documented (Hall 1996, for example). These relationships are key factors in developing a sustainable built environment. However, the fundamental question remains: How can planners strike a balance between these three aspects in order to develop an attractive built environment where travel is minimized and environmental quality attained? When considering the connection between the first two aspects, land use and transportation, Hall (1996) claimed that planners should consider these two factors as meshed together into a highly fragile combination. That is to say, connecting and harmonizing land uses and transportation so that both elements will coexist in a good manner is not easily accomplished. Hence, when a planner looks at these aspects, he must do so in a delicate manner to create a win-win situation.In dealing with the connection between land use and transportation, O'Meara (1998) argued: "The physical structure of a city cannot change overnight, but decisions about transportation and land use will determine how it is shaped over time. By building roads, rail lines or bike paths, city planners decide not only how people will move around, but also where the accessible and desirable buildings will be…" (p. 11). Newman and Kenworthy (1992) elaborated on the connection between land use and environmental aspects: "The great challenge in our cities is to protect individual freedom in locating land uses and to provide access to them, while maintaining the public qualities of clean air, safe streets, and attractive public spaces" (p. 360).Although the question concerning the optimized planning form still exists (a question which has a long history in planning research literature), it is commonly agreed that city structure and planning can help to develop a sustainable built environment. That is, urban planning can play an essential role in creating sustainable relationships between land use, transportation, and environment.The aim of our study was to investigate the impact of city form and planning ideas/scenarios on transportation, land use, and the environment in developing a sustainable built environment. In other words, can urban planners formulate a planning form/scenario that will reduce travel and consequently pollution while simultaneously creating a sustainable built environment by suggesting the opt...