Summary
Traditionally, transportation flow (TF) is defined as the “movement of vehicles carrying various types of cargo and passengers between different geographic destinations or within a certain region” (Davulis & Sadzius, 2010, p. 19). As a rule, the density of the TF may vary depending on the number of vehicles on the road, the width of the latter, the time of the day that the TF is measured at, etc. The above-mentioned characteristics of TF often define the transportation costs spent on transferring people or objects. In their case study, Xie, Waller and Kockelman (2010) analyze the approaches that can be used in order to improve the quality of transportation flow in the traffic congestion environment.
Problem
In the case study under consideration, the issues related to the traffic congestion concern are dealt with. Specifically, the authors of the research outline the reduction in the efficacy of the transportation flow, which is caused by the traffic congestion. According to the solution suggested by the authors of the study as the key means of addressing the problem, the joint use of lane reversal and crossing elimination should be considered in order to make the transportation process less expensive and time-consuming. The designs suggested by the authors incorporate the decision to accommodate the outbound traffic in a more adequate manner by carrying out the reversal of the traffic direction on the inbound lanes and the change in the designated roadways (Xie et al., 2010, p. 106).
The solution, which Xie et al. (2010) suggest for improving the TF in the specified area is quite original, yet completely adequate. According to the authors of the study, the O-D flow organization problem can be resolved with the adoption of a combination of a branch-and-bound and a simple-based method for designing the best transportation route possible (Xi et al., 2010, p. 113). Therefore, the study is a graphic example of the fact that, with a distribution allowing for reducing the density of the TF, the latter becomes much smoother and faster. In addition, the authors make it quite clear that the O-D flow optimization problem is linked directly to the flow distribution concerns (Xie et al., 2010, p. 108).
Significance
Though the pattern of the transportation flow change as the effect of the reconsideration of the distribution strategy suggested in the case study by Xie et al. can be viewed as a unique solution to a very specific problem, the ideas that are conveyed in the paper, as well as the approach adopted to the solution of the issue altogether, clearly deserves a closer attention (Hultkrantz & Lumsden, 2004). On a larger scale, the idea of introducing a joint use of lane reversal as the means for improving the transportation process and optimizing the flow within a specific area with high congestion rates can be viewed as a temporary solution for traffic congestions within any area that is located in the environment suitable for carrying out a line reversal (Guo & Liu, 2013). Thus, the significance of the study conducted by Xie et al. (2010) is rather high. It should be born in mind, though, that the solution suggested is only suitable for the areas with rather wide roads and a large number of cross-sections; otherwise, the solution designed by Xie et al. (2010) becomes pointless.
Alternative Action
One must note, though, that the solution provided by the authors of the study is not the only possible approach for addressing the issue in question. The problems related to the traffic congestion could also have been resolved with the help of the changes in the current logistics strategy of the company. Specifically the type of transportation, as well as the deadlines, could have been altered so that the process could occur in a more rational manner. For instance, it would have been a good idea to spend more on the provision of high quality transportation process, i.e., facilitate a better safety of the products transferred (Koskela et al., 2011).
Recommendation
It can be suggested that the distribution of transportation process should be based on the principles of uninterrupted flow. Thus, not only will the TF be optimized, but also the possibilities for cutting the costs for transportation and maintenance processes will emerge (Xie et al., 2010, p. 106). Indeed, with the distribution process based on the concept of lane reversal and crossing elimination, it will be possible to avoid major congestions, which, in its turn, will lead to a smoother TF and a more rational use of the transportation resources. However, apart from the specified approaches, the idea of incorporating a multi-commodity flow distribution should be considered. With the help of the specified design, one will be capable of controlling the TF better, therefore, creating the premises for an uninterrupted flow. The multi-commodity TF will lead to the rearrangement of the elements of the TF process and a better classification of the latter; as a result, the designs for the optimum location of various types of transport and the definition of the most favorable routes for specific transportation types will become a possibility.
Reference List
Davulis, G. & Sadzius, L. (2010). Modelling and optimization of transportation costs. Intellectual Economics, 1(7), 18–29.
Guo, J. & Liu, Q. (2013). Advances in civil, transportation and environmental engineering. London, UK: WIT Press.
Hultkrantz, O. & Lumsden, K. (2004). The impact of e-commerce on transport. Web.
Koskela, S., Dahlbo, H., Judl, J. & Korhonen, M.-R. (2011). LCA comparison of two systems for bread packaging and distribution. Helsinki, Finland: Cleen, Ltd.
Xie, C., Waller, S. T. & Kockelman, K. M. (2010). Intersection origin-destination flow optimization problem for evacuation network design. Transportation: research record, 2234, 105–115.