Bayan Bevrani

A case study of the Iranian national railway and its absolute capacity expansion using analytical models

Identifying railway capacity is an important task that can identify ‘in principal’ whether the network can handle an intended traffic flow, and whether there is any free capacity left for additional train services. Capacity determination techniques can also be used to identify how best to improve an existing network, and at least cost. In this article, an optimization approach has been applied to a case study of the Iran national railway, in order to identify its current capacity and to optimally expand it given a variety of technical conditions. This railway is very important in Iran and will be upgraded extensively in the coming years. Hence, the conclusions in this article may help in that endeavor. A sensitivity analysis is recommended to evaluate a wider range of possible scenarios. Hence, more useful lower and upper bounds can be provided for the performance of the system. nFirst published online:xa011 Oct 2015

A capacity assessment approach for multi-modal transportation systems

This article focuses upon multi-modal transportation systems (MMTS) and their capacity assessment. To perform this task, a linear programming model (LP) denoted by MMTS_CAP has been developed. This model determines the maximum flow of vehicles and commodities that can be accommodated, over a given time period, on different transportation modes within the MMTS. It chooses how to move commodities between different origin destination pairs (ODP) and facilitates the transfer of commodities across different modes. The proposed model can facilitate a variety of capacity planning and querying activities and provides a mechanism to quickly analyse the effect of structural and parametric changes within MMTS. The model has been applied to several scenarios, including a real life case study. Our numerical testing indicates that it is effective, highly flexible and extendable. Our analysis suggests that the proposed capacity assessment techniques are worthwhile and may help transportation planners build better MMTS.