Abstract for: Why Achieving a Sustainable Transportation System Seems Impossible for Tehran
The issue of traffic congestion in Tehran, the capital city of Iran, has become a Gordian knot. Numerous studies have been conducted to find the optimal solution for this problem, many of which not being successful in practice. The city’s public transportation development, namely the subway system, which many experts believe is the key to solving Tehran's traffic problem, has not received enough attention. In this article, using the dynamic system approach, we intend to explain: (1) Why the subway system in Tehran is underdeveloped, in favor of more highway construction, despite its importance in reducing traffic congestion having been realized? (2) Why weren’t the past policies successful in Tehran, despite the same policies making positive changes in other metropolises around the world? (3) Can the development of the subway system really solve the problem of traffic and pollution in Tehran? To answer these questions, Sterman's model [17, P.177] is adopted, and two new sectors are added to it. Additionally, fifteen policies in the literature are systematically reviewed, and the reasons for their failure are investigated. In the end, we propose a policy which helps mitigate the problem of traffic congestion in Tehran.