In order to achieve sustainability objectives, spatial modeling and simulations dedicated to land and urban planning are increasingly useful for producing prospective scenarios to guide stakeholder decisions and actions. These scenarios are usually assessed by way of numerous economic, social, and environmental indicators, but they are rarely combined within a synthetic approach for global assessment and scenario comparison. From an example applied to the Greater Besançon area, this paper presents a methodology for generating synthetic indicators. The paper is innovative in that it proposes a method for combining such indicators. This consists of three steps: (i) evaluation, (ii) aggregation, and (iii) combination, leading to decision support for decision-making. Based on this method, a grid analysis map of the study area (Besançon) is produced from which the strengths and weaknesses of the territory can be identified in terms of sustainability. The resulting maps are relevant and useful, although they inevitably raise some fundamental and theoretical questions about the implementation of sustainable development principles at the scale of an urban region. These are discussed in the conclusion with news maps.