Criteria Prioritization for Feasibility Studies of Multilevel Urban Roads Construction by Factor Analysis

It''s not too hard to see how urbanization and boost of vehicle production have been increasing the tendency toward using private vehicles in decades. Consequently، demand rate have been increased and، now، traffic jam is an inseparable part of urban road networks. Therefore، beside demand management policies، expanding roads'' capacity is also inevitable. Although road capacity could be easily increased by adding new lanes in past، various limitations make building multilevel roads more popular rather than constructing additional lanes in many metropolitans. In this paper، authors try to determine effective factors in urban multilevel road feasibility studies by studying other countries'' experiences and designing a questionnaire based on collected data. Transportation and urban design experts are asked to fill the questionnaires and the factors are classified and prioritized by factor analysis. The results illustrate that «Road level of service in peak hours»، «Historical places'' preservation»، «Noise pollution»، «Capital cost»، «protecting urban linear centers»، «Number of bottlenecks»، «safety considerations (number of accidents)»، and «Link''s daily volume» are the best 8 chosen factors for further studies. These factors could cover 30 proposed measures without wasting time and money.