- A hybrid system for evaluating the effect of city scenarios and planning ideas is presented. It combines a computerized model and the planner's practical inputs. The system includes several sub-models for establishing land use maps and facilities for combinations of two city forms in terms of main roads structure and two planning ideas. The outcome city-maps that are created by the numerical procedure have a major impact on the air pollution associated with aspects of travel within the city, combined with the characteristics of the specific population which is addressed in planning. These computerized maps set the basis for a second stage in which the planner is manually changing the maps and reevaluates the effect of its input on the pollution emission from transportation. These combined/hybrid actions of a computerized model and the interference of the planner bring to an optimized city plan in terms of pollution emission on one hand and optimized mobility and sustainability on the other.