JOURNAL OF TRANSPORTATION RESEARCH
Year:2019 | Volume:16 | Issue:2 (59) |Papers Count:18

Rail transit is an important section of rail transport in Iran. Exploiting the potentials of rail transit could have economic benefits for the country; however it seems that the current gains from transit are far behind its potentials. This research uses SWOT analysis to propose a strategic plan for improving Iranian rail transit. We develop a comprehensive list of strengths, weaknesses, opportunities and threats. We ask experts to score the items thereby we can select the most important ones. Making interaction matrices, the competitive strategies (WO) followed by conservative strategies (ST) are determined as the appropriate strategies for Iranian rail transit. Different short term and long term tasks are proposed based on the selected strategies. The tasks include: completion and expanding the rail network along the main corridors; improving the planning and reducing the delays of transit trains; creating a strong and integrated authority to pursue and carry out the transit related tasks.

Applying the tire rubber powder as an additive of bitumen has been one of the considerable topics for the researches. The use of the recycled tire rubber as a measure for protecting the environment moreover the considerable improvement in the bitumen performance and cheaper than the other polymers make the topic more important. In this research, in addition to the tire rubber powder, it has been tried to use the asphalt recycled from reclaimed asphalt pavement as an alternative for replacing bitumen. So, a sample of rubber modified bitumen was prepared and combined with different percentages of the recycled asphalt and tested. The aim of the tests has been examining the rutting and fatigue performance of the bituminous binder by the newer methods such as multiple stress creep recovery, temperature and frequency sweep and linear amplitude sweep. The test results showed that adding 15 to 25 percent of the recycled asphalt to the base rubber bitumen has a considerable effect in increasing complex shear modulus and decreasing the phase angle. So, the recycled asphalt improved the elastic behavior of the rubber bitumen and increased rutting resistance of the bitumen. But, the fatigue resistance of the rubber bitumen was decreased.

Nowadays, one of the most important issues in the metropolises of all around the world is using the modern public transportation systems, research and development in this field which indicates the importance of using these types of systems in most countries. One of the most attractive innovation in urban transportation system is using intelligent taxis and improvement in online ordering systems; while in the metropolis of Tehran, the use of smart taxi and optimization of the network coverage is one of the important issues of the municipality. Therefore, in this paper, a new model based on two different strategies for ordering taxis in Tehran is presented for the first time. First, using the concept of the trip chain, a model called trip chain network is presented in accordance with Tehran's situation. After identifying the demand points, a density-based spatial clustering applications with noise (DBSCAN) is used to evaluate the proposed model. To improve the performance of the algorithm and set its parameters, the design of experiment method (DOE) was used and then cluster centers were designated as intelligent taxi stations. The results show centers of these clusters are the best feasible points for developing intelligent taxi stations in Tehran and 53. 12 percent of the points obtained as proposed stations of smart taxis are matched with the current situations. Also, the proposed model can provide the maximum usage of taxis and reduce the wasting time for passengers to access the taxi by striking an equilibrium approach between supply and demand.

The government as a major force has always been in competition and has had a positive and even negative impact on its competitiveness by intervening in various political, economic and social affairs and applying laws and regulations on competitiveness. Building and supporting a suitable environment for increasing the growth of firm productivity and guiding industry trends and encouraging policies rather than helping industrial units help the necessary conditions to enhance the competitive advantage through the impact on each dimension of diamonds is the duty of the state. Unpredictable events are events and issues that affect the competitiveness of either positive or negative, but are randomly controlled outside firms, industries, and even governments. Michael Porter believes that luck in most markets is important. These cases create opportunities for those innovative companies who are not afraid of starting new activities. The type of research, development and in terms of exploratory-descriptive purpose, qualitative research data, the field of field research, the time period of the cross-sectional research, the method of data collection is a survey type. The overall results of the research show that the government and luck components of the National Diamond Model of Michael Porter in the Ports and Ferries of Bushehr, from the perspective of the respondents of the statistical society, had the second and second priorities after the productive and service inputs, which highlighted the importance of these factors in Achieving competitive advantage for this port. Also, regarding the maintenance and development of competitive advantage, in the interview section, the main focus of the interviewees was on the operation and management of these two factors.

The high-speed train is usually referred to as a rail service covering the railway's special services at a rate of 200-300 km / h. Because of its high speed, the transportation system will ease many ease on the intercity accesses, and it is sometimes unavoidable to use it as a safe and fast transport system. The feasibility of the construction of high-speed rail bridges between the two provinces seems necessary because of the Caspian Sea and linking Iran with the northern countries of the Caspian Sea as our dear country's capital. in this study, the feasibility of the construction of a high-speed rail line was proposed, with suggestions for improving the performance of rail lines between the two provinces. Two scenarios were put forward according to the forecast table for passenger transport by the-North railway. According to scenario (1), the average passenger growth rate on the road to Tehran-north will be 2 / 2 %. In the case scenario (2) the average passenger growth rate on these axes accounted for 2. 5 per cent per year, respectively. The results showed that, according to the progress of world countries on high-speed rail access, the necessity of using high-speed rail.

Environment has become an important global issue in the current century. Hence in the recent years, green closed loop supply chain management has increasingly grown as a result of government regulation and consumer expectations. In this study, an effort has made to formulate a facility location model for a multi-period green closed loop supply chain network consisting of suppliers, manufacturers, distributers, customers and also recycling and disposal centers. A bi-objective mixed-integer linear programming model has proposed to design the supply chain network with minimization of total costs and carbon dioxide emission objectives in transportation, production, recycling and disposing processes. In addition in a supply chain, operation cost has major effect on the total cost. So, in this research has tried to consider learning curve (LC) effect on reducing time and cost of the production and recycling in the manufacturing and recycling centers. Then, the effect of using LC on the supply chain cost has investigated. The ε-constraint method has utilized to solve the bi-objective model and illustrating trade-off between objectives. The applicability of the model has demonstrated by a numerical example and sensitivity analysis.

In Iran, the Limitation of Actions in claiming damages due to air accidents is not clear. A Similar issue in The two major international treaties, the Warsaw Convention and the Montreal Convention, has been determined, if an action is not brought within a period of two years, The right to damages shall be extinguished. This limitation comes a conundrum in Iranian law. On the one hand, the liability of air carriers is distinguished based on a domestic law. Although this lapse of time is not expressed in this law, Iran has acceded to the Warsaw Convention and its amendments in the years 1975 and 2015. For this reason, it needs to be determined if this limitation can be extended and come to force in dometic law. To meet this need, tree questions must be be responed. The first question is about the nature of air transport? What Damages to Air Transport Can Happen? And how does Limitation of Actions perform?

Pedestrians are subjected to high levels of risk at non-signalized intersections. Pedestrians at these intersections have conflicts with different types of vehicles such as motorcycles and cars. In this paper, pedestrian safety is compared between those two groups of vehicles using Time to Collision (TTC) as well as the Post Encroachment Time (PET). Data were collected from an intersection called Vesal-Bozorgmehr in Tehran. The one-way ANOVA was used to compare those two groups. The number of observations for each TTC and PET being the dependent variable was 758 and 791 respectively. Analyses indicated that LogTTC in conflicts between vehicles and pedestrians is 0. 03 units more than conflicts between motorcycles and pedestrians and LogPET in conflicts between vehicles and pedestrians is 0. 09 units lower than conflicts between motorcycles and pedestrians. TTC is used for identification of situations being potentially dangerous for pedestrians and PET is used for identification of critical situations for pedestrians. As TTC for the conflicts between pedestrians and vehicles is lower than that of for pedestrians and vehicles, motorcycles potentially cause more dangerous situations for pedestrians whereas when it comes to PET, vehicles have lower PET than motorcycles, so vehicles are more able to make critical situations for pedestrians.

Chip-seal is one of the preliminary though successful ways to improve road surface of the pavement. Chip-seal is a byproduct of similar sized stones which pour in surface after emulsion bitumen wet the road surface. Chip-seal can deteriorate due to bleeding, aggregate streaking and aggregate removal. The first and second damages are sourced from improper design and implementation whereas the last damage is due to a lot of aspects and this study aims to investigate some of them. The effect of existing road surface, bitumen type, aggregate kind and bitumen percentage are examined in this study. The road surfaces which are evaluated in this research were cement treated base. In this research, two kinds of bitumen including: emulsion and rubber powder modified emulsion was used for chip-seal preparation. According to Iran road code numbered 234, two different mixture aggregate grading were recommended for chip-seal preparation. This study used the third aggregate grading which is generally finer compared to others. Also, in this research two different laboratory tests including; sweep tests and sand patch tests used for examination of the mixtures. The sweep tests were used for investigating the effects of aggregate grading kind, bitumen percentages, bitumen kind and the surface which chip-seal implemented. Also, the sand patch tests were used for investigating the effect of aggregate grading and bitumen kind on texture depth of chip-seal. Results of the laboratory tests indicated that rubber modified emulsion bitumen can decrease chip-seal aggregate removal by approximately 20%~23%. In addition chip-seal aggregate removal has a direct relationship with aggregate grading which results showed 14% decrease in aggregate removal when the finer aggregate grading was used. Moreover, results of sand patch tests indicated that chip-seal implementation of cement treated based can improve road surface friction resistance.

Nowadays site selection of an appropriate location for a project can be one of the most important success factors. This research was done in order to find suitable locations for sound barriers in Karaj. In this research, after a literature review and gathering the expert opinions, the criteria and sub-criteria were determined. Then, the standardized criteria and sub-criteria maps were prepared by fuzzy standardization method. To obtain weights of criteria and sub-criteria, the pairwise comparison were used. Then, the suitability map for the implementation of sound barriers were obtained with weighted linear combination (WLC). Next, by field visit and measuring the sound level and examining the possibility of barrier installation, nine routes were selected from the suitability map. In the next step, using the TOPSIS method, priority 9 selected routes were done. The results of this study indicated that the most important criteria for locating sound barriers were urban routes (passages, thoroughfare), equivalent sound level (Leq), urban traffic, land use, population density, sensitive locations to noise, distance to passages, topography (slope), height of buildings, and vegetation respectively. The sound level measuring results showed the most polluted routes were the route 2 (M2), located in the second district of Karaj municipality, route 1 (M1) in the eleventh region and route 5 (M5) in the fifth region respectively. The TOPSIS results showed the appropriate routes were to install the sound barriers were route 9 (located at Golshahr Boulevard) and route 7 (Shahid Rajaee Boulevard – Zafar) and route 6 (Allameh Jafari Boulevard, Islamic Republic of Iran – Aras), and route 2 (Freeway Karaj-Qazvin, Fardis bridge to Golshahr), respectively. The results of this research can be applied to implement the sound barriers by Karaj municipal and this approach can be used in other cities.

Tensile cracking is one of the main modes of deterioration and failure in rigid pavements. Hence, in this paper the effects of roller compacted concrete (RCC) characteristics on their fracture behavior in both pure mode I and II are experimentally investigated. A set of 288 edge cracked beam specimens endured the four-point bending (4PB) test and were tested for different concrete mixtures made with waste materials such as reclaimed asphalt pavement (RAP) and crumb rubber. The influence of aggregate gradation, cement content, RAP, and rubber content on the critical stress intensity factors in pure fracture mode I and II were studied. The fracture toughness results showed that concrete mix specifications had a noticeable influence on the cracking initiation of RCC and the effect of substituting of waste materials with natural aggregates was found to be negative, but their behavior was still comparable to those obtained for control mixes.

Asphaltic concrete has been used as waterproofing core in embankment dams, since 1948. The large majority of embankment dams' central core is made of clay worldwide. However, as clay is increasingly difficult to find at new construction sites, asphalt concrete was used as a replacement core material. Cores made of clay has also some other disadvantages such as, low shear strength, compressibility, long construction time, requiring higher amount of material and accurate controls during construction, etc. These are in favor of using asphalt concrete, which has advantages such as less sensitivity to weather conditions, less width of core, healing behavior of bitumen, high shear strength etc. In this application, granular materials are used around the asphaltic concrete as filter, which makes a complicated behavior in the interface and needs to be researched by experiments and modeling. This paper describes experimental work and the results of investigating the mechanical behavior of the interface between aggregates and asphaltic concrete. Small scale shear strength test has been used in this study, in which the shear surface is considered as the interface. The effect of bitumen penetration grade, moisture, density and angularity of aggregates on the shear strength parameters at different levels of vertical stresses and a constant shear rate was studied.

Undoubtedly, container transportation is one of the factors contributing to the development of transportation and its speed in the today world. But the problem remains in the container transportation area as an unresolved issue is the empty container problem which due to the unbalancing between export and import of goods in all ports of the world. In this paper, investigated the reposition of empty containers under uncertain conditions of some problem parameters. a robust scenario-based approach based on the scenario tree analysis method has been used under different scenarios to modeling the uncertainty of some of the problem parameters. In order to evaluate and validate the proposed model, the data from Iran maritime port network are used. The computational results indicate the appropriate performance of proposed robust model, under uncertainty conditions, and also the importance of using robust approach in creating reposition of empty containers robust plans under uncertain conditions.

Ecological Footprint Assessment (EFA) is one of the methodologies attracted more attention at political, educational, and academic levels. The growth of Sanandaj population affects the traffic congestion which is a main problem of the city. This study addresses this gap as well enhances the environmental conditions by reducing fossil fuel consumption. For this purpose, Ecological Footprint (EF) method was applied to evaluate the sustainability of the current transportation system and consequently an optimized model was suggested for 2026. Comparing EF of the current transportation system with the world standards, demonstrated that many transportation types such as minibus, taxi, and private cars have a high level of EF. Based on the predicted population for 2026, 457390 people, the optimized transportation percentage shares were proposed, including 6. 71, 57. 02, 16. 31, 19. 08, and 0. 88 for minibus, bus, taxi, private cars, and motorcycle respectively. Applying the new plan can save 16132 litre fossil fuel as well as 11 tons CO2 annually.