Two Comprehensive Strategies to Prioritize the Capacity Improvement Solutions in Railway Networks (Case Study: Iran)

The aim of this study is to present two comprehensive strategies for prioritizing the capacity improvement solutions in the railway networks. The solutions considered in this study include: promoting to double-track railways, block signaling system, electrification and re-opening the closed stations. The first strategy is based on a local approach, which concentrates on the critical block sections individually; whereas the second one is based on a global approach, for which the solutions are executed according to the load flow of the network and the capability of the demand absorption after removing the bottlenecks emerged in the specific corridors. For both strategies, the value of the absorbed excessive demand, the benefits, the costs, and the net present value (NPV) indicator are employed to compare the solutions. To evaluate the proposed strategies, Iranian railway network was examined. The results demonstrate the excellence of the second strategy, rather than the first one. By executing the first and the second strategies, 45.6 and 52.52 million tons per year, of the total potential demand can be absorbed to the network, respectively. The NPV values were 5.78 and 7.81 billion dollars for the first and the second strategies, respectively. In spite of more investments required, the second strategy is more efficient, rather than the first one.