an overview of strategic mistakes in alteration of urban development plans in iran and their implications for transportation planning

Master and detailed plans, as core components of urban development plans (udps), play a fundamental role in urban planning in iran. while these plans may be modified when necessary, such changes must be approached with great caution. this is because gradual land-use changes can significantly alter travel demand patterns, leading to substantial transportation costs. this paper investigates the long-term impacts of strategic decisions in urban development on transportation costs within an urban network. to this end, the paper first identifies key risks associated with modifying urban development plans, particularly at the detailed planning level. one potential outcome, trip concentration, is then examined, wherein long-term travel demand growth becomes concentrated in one or a few attractor zones within the network. a computational example is presented to illustrate the cost implications of such concentration. in this example, the sioux falls transportation network is analyzed under two scenarios of increasing demand: uniform growth and concentrated growth. the findings indicate that with a 50% increase in trip demand, the transportation costs in the concentrated growth scenario rise significantly. moreover, under a 100% demand increase, even the implementation of over 20 infrastructure projects fails to mitigate the costs, which remain three times higher than those under the uniform growth scenario.