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International Journal of Transportation Engineering
Number of Followers: 2

This is an Open Access Journal

Open Access journal
ISSN (Print) 2322-259X - ISSN (Online) 2538-3728
Published by Tarrahan Parseh Transportation Research Institute

[1 journal]

Comparing the Accessibility of Rescue Centers in the Districts of Tehran
Municipality after ...
- Abstract: In this research, the centers involved in relief operations in Tehran traffic area districts have been compared and the supply-demand ratio has been specified through a relation presented separately for each district. The supply has been evaluated based on three parameters: 1) No of relief centers, 2) congestion of the main road (the ratio of the length of the main road to the area of the district), and 3) the ratio of the length of the main road to those of the secondary roads. The demand has been considered based on the number of casualties waiting for relief per unit area of each district.After delimiting the districts in the case study and extracting the network’s populations and roads information layers in the GIS, two road classes were specified: 1) main roads (capable of working under disaster conditions) and 2) secondary roads (capable of obstructing relief operations in needy areas). Next, the parameters were co equalized with their corresponding maximum values and scaled in the 0-100 range. The final results have been shown separately for each district (totally 32 in number) as the accessibility index. Accordingly, districts with indices smaller than 2 are considered as weakly accessible and those with indices more than 15 as properly accessible; districts with indices 2-8.5 have average accessibility.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Car Use Behavioral Study for Commuting Trips: Parents’ Work Trips and
Children’s School Trips
- Abstract: Negative consequences of car use along with deficiencies for investment in environmental friendly modes, have driven authorities to search for soft measure in order to encourage people for modal shift. The main objective of this study is to propose a model which describes car use behavior on parents’ work trips and how this relates to mode choice regarding their children’s school trips. A questionnaire survey was carried out in 24 randomly selected primary schools in Tehran, Iran (n=4000). A mean structural analysis based on the sample (returned questionnaires =1876) demonstrates that parents who accompany their children on school trips have a stronger intention to use car for work trips than parents who do not accompany their children on school trips. A structural equation model based on the theory of planned behavior suggests that using car on school trips along with car use behavior for work trips, significantly increases the car use behavior for work trips. Findings suggest that individuals as parents, and also parents who accompany their children on school trips need to be considered in planning and policy setting for modal shift providing soft measures sensitive to this issue, since parents are highly influenced by their parental roles involved with children’s requirements in school trips.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Modelling and Solving the Capacitated Location-Routing Problem with
Simultaneous Pickup and ...
- Abstract: In this work, the capacitated location-routing problem with simultaneous pickup and delivery (CLRP-SPD) is considered. This problem is a more realistic case of the capacitated location-routing problem (CLRP) and belongs to the reverse logistics of the supply chain. The problem has many real-life applications of which some have been addressed in the literature such as management of liquid petroleum gas tanks, laundry service of hotels and drink distribution. The CLRP-SPD is composed of two well-known problems; facility location problem and vehicle routing problem. In CLRP-SPD, a set of customers with given delivery and pickup demands should be supplied by a fleet of vehicles that start and end their tours at a single depot. Moreover, the depots and vehicles have a predefined capacity and the objective function is minimizing the route distances, fixed costs of establishing the depot(s) and employing the vehicles. The node-based MIP formulation of the CLRP-SPD is proposed based on the literature of the problem. To solve the model, a greedy clustering method (GCM) is developed which includes four phases; clustering the customers, establishing the proper depot(s), assigning the clusters to depot(s) and constructing the vehicle tours by ant colony system (ACS). The numerical experiments on two sets of test problems with different sizes on the number of customers and candidate depots show the efficiency of the heuristic method with the proposed method in the literature. Finally, performance of the heuristic method to the similar methods in the literature is evaluated by several standard test problems of the CLRP.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Evolutionary Approach for Energy Minimizing Vehicle Routing Problem with
Time Windows and ...
- Abstract: A new model and solution for the energy minimizing vehicle routing problem with time windows (EVRPTW) and customers’ priority is presented in this paper. In this paper unlike prior attempts to minimize cost by minimizing overall traveling distance, the model also incorporates energy minimizing which meets the latest requirements of green logistics. This paper includes the vehicles load as an additional indicator of the cost in addition to the distance traveled cost. Moreover, this paper tries to maximize the customers' satisfaction using their preference and considers the customers' priority for servicing. Every customer is assigned to a group (e.g., very important, important, casual and unimportant) and the customers’ preference is represented as a convex fuzzy number with respect to the satisfaction for service time. The detailed mathematical formulation of proposed model is provided and it is interpreted as multi-objective optimization where, the energy consumed and the total number of vehicles are minimized and the total satisfaction rate of customers is maximized. In general, the relationship between these defined objectives is unknown until the problem is solved in a proper multi-objective manner. Thus, a multi-objective evolutionary algorithm is proposed and its performance on several completely random instances is compared with Non-dominated Sorting Genetic Algorithm II (NSGA II) and CPLEX Solver. The hypervolume indicator is used to evaluate the two Pareto set approximations found by NSGA-II and the proposed approach. The performance proposed evolutionary is further demonstrated through several computational experiments and the results indicate the good quality of the method.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Evaluation and Relocating Bicycle Sharing Stations in Mashhad City using
Multi-Criteria Analysis
- Abstract: The purpose of this study is to evaluate the present status of Mashhad’s Bicycle Sharing (BS) Program's stations, and to locate future stations, taking into account the 7 criteria of “proximity to subway stations”, “proximity to other stations”, “distance from important intersections”, “distance from population centers”, “proximity to educational, recreational and commercialcenters”, “slope level” and “proximity to cycling infrastructure (bike lanes)”. The approach employed by the present study is Multiple-criteria decision making (MCDM) and Fuzzy membership maps and Analytic Hierarchy Process (AHP) based on GIS to weight the 7 mentioned criteria, also the stations will be ranked based on VIKOR approach and finally categorized through Jenks natural breaks classification method (JENKS). In order to analyze the data ArcGIS 10 software has been used. The findings show that 26 stations (20.3%) are very unsatisfactory and 25 stations (19.5%) are unsatisfactory among the total 128 stations that have been built so far. The findings also indicate that there are a lot of stations with very unsatisfactory conditions on the borders of the coverage area of the BS program which imply that widespread coverage has been prioritized over efficiency and proper distribution of the stations. Also 22 planned stations that have been stipulated in the contract between Mashhad’s municipality and the beneficiary firm have been located based on the ratings that were assigned. This study, as the first study with the mentioned approach on this subject in Iran shows that priorities regarding the performance of BS program may not be well conceived in different regions and cities, especially in developing countries with their own specific conditions. Thus, in this research we have tried to present the existing problems in locating the stations, and contribute to development of the existing programs and possible future programs in other cities.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Determination of Effective Travel Variables on Air Transport Demand with
Using Structural Equation
- Abstract: Air transport system has always been involved in all aspects of life because of its high potential in transporting passengers and goods. In this research we surveys the effects of travel variables on demand of domestic air transport, and for gathering required information from passengers, a questionnaire was designed including 20 effective parameters on air transport demand with questions These parameters were investigated based on their importance using “Factor Analysis” and finally proved that the factors “price paid by passengers”, ”services offered by air transport system” and “time” has had the greatest impact on air transport demand with more than 20 % influence. “Structural Equation Modeling” has been used for checking the “Factor Analysis” results. The results of the model proved the correctness of factor analysis. Furthermore, the result of factor analysis has showed that the most important parameter has been “low cost travel” with the factor load of 0.9-1 in all case studies. Results show that both groups with factor load of more than 0.5 in the obtained factors have identified the factor “services” as the important and effective factor with the influence value of more than 20%.
  PubDate: Mon, 31 Dec 2018 20:30:00 +010
Multi-objective modeling based on competition airlines cooperation by game
theory and ...
- Abstract: In each time period, the demand of passengers for each route are finite and airlines compete for earning more profits. The complex competition among airlines causes problems, such as complicating flight planning and increasing empty seats for some routes. These problems increase air pollution and fuel consumption. To solve these problems, this research studies the cooperation of the airlines with game theory and sustainable development approaches. To investigate the issue, the following three steps are suggested: introducing the components of the multi-attribute game theory to the multi-objective model, modeling multi-objective formulation with a sustainable development approach, and solving the model by a multi-objective method. Payoff functions are to maximize the profit of airlines, minimize the total difference among the numbers of flier passengers and their demand on all routes and all flight times and, and minimize empty seats. All the above-mentioned objectives present economic, social, and environmental aspects of sustainable development. The results of the airline cooperation model are compared with the information about non-cooperation collected from airlines in the current form. The cooperation of airlines can improve the objective functions and the sustainable development approach. This research can be used to help airlines in identifying the role of cooperation in air transportation.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010
Turnouts defect detection using image processing
- Abstract: Despite other modes of transportation, trains move just along one dimension. However, trains inevitably change their track or even move to the opposite track in railway stations and ports using switch systems. Switches are vital for better operation and seamless movement of trains. Furthermore, they are of crucial importance for safety of movement in tracks due to high derailment potentials at switches; therefore, all parts of switches need to be continuously monitored. Increasing number of accidents in railway systems is highly dependent on switch performance. According to the Islamic Republic of Iran Railways, 90 percent of railway accidents in Tehran stations occur on switches from which 25 percent happen due to switch defects. Therefore, condition evaluation of switches is of significant importance. Research studies have not been sufficiently conducted on automated condition evaluation of switches. This paper aims to develop a robust automated approach to evaluate switch condition to be able to measure switch defects. Having taken some pictures from various switches with fixed angles and distance from rails, an image processing technique is applied to determine defects. The first step of image processing is to preprocess the images to increase their quality. The second step is to indicate the type and severity of defects using different algorithms. A Graphical User Interface (GUI) is developed to develop a user-friendly tool to be able to load images, pre-process the images, measure defects, and report the health condition of switches. Finally, the outcomes are validated through application of ground truth which ends up with a high accuracy of approximation of 87 percent.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010
Performance Assessment of the 2010 HCM and Its Calibrated Model in
Estimation of Weaving and ...
- Abstract: Calibration is a conventional method which is utilized to adapt traffic models based on local situations in order to achieve best results. One of the issues regarding the efficiency of this method is whether traffic models should be calibrated only in one or two major cities of a country or calibrated based upon a comprehensive selection of cities. Therefore, this study, which has used the actual speeds, attempts to evaluate the performance of the weaving model that was proposed in the fifth edition of Highway Capacity Manual (HCM 2010) and its calibrated model, which was calibrated in Tehran highways. In this regard, adequate field-data were collected on a ramp-weaving segment in Isfahan. The procedure was of 9 fifteen-minute time steps of recording at different hours of a working day. The analysis results indicated poor and appropriate performances by the HCM 2010 model in estimating speeds of non-weaving and weaving vehicles, respectively, for which the RMSE (Root Mean Square Error) values were obtained as 16.34 km/h and 2.11 km/h, respectively. Moreover, not only was the calibrated model unable to improve the performance of the original model, but also it affected the original model negatively and caused a larger difference in the model output compared to the actual values. Hence, calibrated models based on metropolises such as Tehran may not necessarily be applied to other cities and may lead to unrealistic results. This reflect the fact that traffic patterns in two cities of one country may be highly dissimilar.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010
Supply chain coordination through lead time crashing in a socially
responsible supply chain ...
- Abstract: In this paper, a socially responsible supply chain consisting of one supplier and one retailer is proposed. The supplier decides on replenishment cycle multiplier and the retailer invests in corporate social responsibility (CSR) and decides on the order-up-to-level under a periodic review replenishment policy. The retailer’s decisions impact on the supplier’s probability as well as the supply chain. Therefore, the supplier proposes a lead time crashing contract to entice the retailer to participate in the coordination model. In this paper, the supplier can reduce the lead time by spending more cost and select a faster transportation mode. Two transportation modes (fast and slow) are considered in the proposed contract. By selecting a fast transportation mode, the retailer’s inventory cost and shortage will be decreased. Therefore, the retailers’ profit will be increased, while the lead time reduction cost and carbon emissions tax are imposed on the supplier under the lead time crashing contract. Numerical experiments and sensitivity analyses also show that the lead time crashing contract can coordinate the proposed model and the profit of supply chain and both members will be improved. Moreover, according to this contract the extra profit that is achieved from the coordination model is shared between both members of the supply chain fairly.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010
Supply Chain Scheduling Using a Transportation System Composed of Vehicle
Routing Problem and ...
- Abstract: This study considers a combination of cross-docking and vehicle routing problem (VRP) approaches to transport raw material and parts in a supply chain. The supply chain is composed of some suppliers which are spread in different geographical zones and multiple shared vehicles with different speeds and capacities for transporting orders from the suppliers to a manufacturer. After proposing a mathematical model of this new problem, a developed version of genetic algorithm based on a psychological theory, named Reference Group Genetic Algorithm (RGGA) is used to solve the problem. The originality of this research is proposing a new method in integrated production and transportation scheduling in supply chain by combination of cross-docking and VRP approaches, presenting the mathematical model of the problem and adapting RGGA to solve it. To evaluate RGGA performance, we develop a genetic algorithm proposed for the nearest problem in literature and compare these two algorithms. Moreover, RGGA results are compared with optimum solutions by some low size test problems. The result shows the good performance of RGGA.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010
Coordination of competitive advertising via investing in transportation
lead time reduction
- Abstract: In this study, a contract for vertical and horizontal coordination is developed in which transportation mode and carbon emissions tax play a key role in determining the values of the contract parameters. The contract is designed for simultaneous coordination of cooperative advertising and periodic review replenishment decisions of a supplier and two competitive retailers. To obtain the optimal decisions, firstly, the traditional decision-making structure is modeled. After that, the centralized structure is modeled to obtain decisions that are profitable for the whole supply chain. Finally, for convincing the competitive retailers to accept the centralized decisions, the supplier applies a lead time crashing contract in which two transportation modes, i.e. fast and slow, can be used. Considering the carbon emissions tax imposed by the government, the coordination contract is designed in such a way that the supplier considers the trade-off between reducing lead time and paying tax on carbon emissions while providing enough incentives for the competitive retailers. Results of the sensitivity analyses showed that the proposed model is profitable from economic and environmental viewpoints. From environmental viewpoint, considering the carbon tax leads to a decrease in the carbon emissions that will be released by the transportation modes. From economic viewpoint, coordinating coop (cooperative) advertising and replenishment decisions of the SC members, enhances demand and provides a higher service level, which increases the SC profit. The contract is conditionally applicable under situations where the carbon emissions tax or lead time reduction costs become high.
  PubDate: Tue, 12 Jun 2018 19:30:00 +010