Studying importance of road safety in evaluating and prioritizing alternatives for the construction of road network (Case Study of Tehran City)

Road network development is an objective of urban transportation planning. In evaluating and prioritizing alternatives for the construction of Tehran network, the traffic measures like travel speed have the first place of importance, and the environmental measures have the second, while the safety measures are not considering at all. Although increasing of the travel speed leads to momentary satisfaction of drivers, it increases the probability of occurring fatal and injury accidents whose their costs are irreversible. According to this conflict, evaluating and prioritizing alternatives for the construction without accounting for the safety measures may lead to undesirable development of the network.