Sustainable city-plan based on planning algorithm, planners' heuristics and transportation aspects

A multi-agent model is applied to develop and asses the impact of urban forms in terms of sustainability measures. The aim of this model is to understand and draw conclusions concerning the planner's options to arrive at a plan, which reflects a sustainable built environment in terms of transportation, distribution of facilities, and minimization of pollution emission from vehicles. The relationships between transportation, land-use, and the environment are key factors for developing a sustainable built environment. The fundamental question is: What is the optimal city-form where equilibrium is reached? Of course, no single answer can be given due to the many aspects which come into play, such as city size, distance to other cities or to service centres. However for each city size and population preferences, a specific city form should lead to a sustainable environment. In this study, we suggest that the multi-agent model can be a useful support tool for planners to assess sustainability issues in their plan development. We examine city plans that differ in their main road-network. Two city forms/structures are considered, and these are the "compact city" and the "multi-nuclear city". The land-use distributions that are obtained reflect these road/city-form alternatives, combined with input data about people preferences. This leads to the possibility to simulate distribution of facilities that takes into account predicted activity-travel patterns of individuals, using an activity-based model of transport demand, estimated on the basis of a comprehensive survey. The analysis of travel in the city, in turn, leads to the evaluation of parameters such as total travel distance per day, number of daily trips as well as accessibility characteristics of the planned city. This enables an analysis of pollution emission from vehicles and comfort of accessibility. Planner heuristics is incorporated in between calculation stages so that the procedure as a whole would lead to a realistic and desirable result. The presented model which is a combination of a theoretical simulation and realistic planner input can be used in urban planning actual practice. Relevant planning examples where this procedure can be used are new master plans for actual cities, in which major population increase is expected, or in a new development (neighborhood, city etc).