پژوهشنامه حمل و نقل
سال چهاردهم شماره 3 (پیاپی 52، پاییز 1396)

Delay caused by workzone activities has been one of the most important issues affecting maintenance and rehabilitation activities on freeways. Not only this kind of delay increases the road user costs, but also can raise public dissatisfaction. This delay mainly results from queue generation and subsequent speed reduction in this area. In order to develop an appropriate delay model, at first, the workzone was modeled using Aimsun microscopic simulation software. Next, the time delay produced by the lane closure for different input volumes and workzone length was determined. According to the results, the capacity inside the workzone was calculated as 1700 vehicle per hour. Moreover, it was identified that volume to length parameter is more affecting when it comes to workzone delay. Finally, taking advantage of SPSS21 and evaluating various kinds of regression models, a multiple nonlinear one was recognized to better explain the workzone delay in freeway two-lane roads.

Population growth, migration from rural, urban development and increasing vehicle creates an important topic in the name of transport and urban traffic and consequently the complexity of this issue to develop a comprehensive and integrated management of transport and traffic has become inevitable. In urban planning system, there is a direct relation between land use, physical criteria and offered supply of transportation facilities. So the aim of this research is considering physical, transportation and population criteria involved in traffic so that with combining existing indexes by using IHWP model evaluate the points having traffic potential in urmia city. This research according to its purpose is the kind of applied research and according to method of work has descriptive- analytical nature. To perform the study, 14 indicators from among the factors affecting traffic were selected and after distribution questionnaire between elites, the scores of indicators based on IHWP are calculated. Preparation and Fuzzy fiction of layers based on the relationship of indicators with research aim and according to Sigmoidal functions respectively has done in GIS and Idrisi software and finally by using Weighted Sum the combination of 14 indicators with applying their scores, is done. Transportation researches orientation to traffic modeling with sectorial and limited number of indicators and led to this research by combination of different transportation, population and physical sub- criteria evaluate the traffic congestion potential in the cities. The results show that 17 percent of urmia city area in low traffic potential, 77 percent in middle potential and 6 percent located in high traffic potential area. As a result, it can be said that much of Urmia area in terms of traffic potential is locate in average traffic zone. The results also in separation of 5 regions suggest that regions of 5, 4 and 2, 3 and 1 respectively the highest to the lowest potential in high traffic zones are allocated.

Recycling Steel slag aggregates into the asphalt mixes improves their performance; however, increasing the bitumen consumption as a result of this recycling bridle its wide spread application. To overcome this difficulty, this research investigates feasibility of concurrent recycling of reclaimed asphalt pavement (RAP) and steel slag into the warm mix asphalt. To this end, six types of asphalt mixture with two coarse steel slag aggregate percentages (0 and 40%) and three RAP contents (0, 20, and 40%) were prepared in two states of aging (short- and long term) and their resistance against rutting, cracking, and moisture-induced damages were examined and compared statistically. Results showed that incorporation of steel slag aggregates and RAP enhances the rutting and cracking performance of mixes; however, the former reduces and the latter one increases the moisture susceptibility. On the other hand, inclusion of RAP and steel slag in mixes respectively degrades and promotes the deformation of asphalt mix at the failure in indirect tension test. Overall, it is proven that simultaneous recycling of steel slag and RAP into the WMA not only is beneficial from economic and environmental perspective, but also leads to a mix which performs better or at least comparable to the conventional mixes and also the mixes that are made with one of these waste materials.

One of the technical problems of hot mix asphalt (HMA) in Yazd province is skid resistance. The cause of this problem is the micro-texture (fine texture) of limestone aggregates. The Ghoghart iron mine of Bafgh (Yazd) has million tons of hard and qualified siliceous aggregates which are depot as waste and unusable materials. In this study, the skid resistance and the chemical and physical properties of aggregates have been evaluated. Also, the methods for modifying the moisture sensitivity problem of these types of aggregates have been expressed. The results of this study indicated that aggregates made from mine waste of Bafgh Ghoghart iron mine have better skid resistance compared to conventional limestone aggregates. Also, it was found that the problem of moisture sensitivity of these aggregates will be avoid by adding zycotherm and zycosoil. In addition to the technical advantages, the environmental benefits of using mines waste of Bafgh is considerable.

Prediction and control of settlement have great importance both in terms of safety and economic point of view on urban area. Tehran subway- line 6 starts from Kouhsar square in the end of north Kouhsar Boulevard placed in north-west of Tehran and ends in Dolat-abad terminal at south of Tehran. North part of line 6 excavated using NATM method. Monitoring and instrumentation system are well equipped and their data have been processed during excavation. Although geotechnical parameter obtained from laboratory and in-situ tests and on the other hand there are distances from sample location to tunnel route, it is possible that different factors such as local heterogeneities in layers or variation of soil between two positions affect the geotechnical parameters. One of the best methods to evaluate these parameters in large scale is back analysis based on instrumentation results. In this paper numerical modeling are done with Plaxis2D software and using back analysis, geotechnical parameters estimated. Different parameters such as cohesion, angle of friction, elastic modules investigated. Also, stresses relaxation were examined before support installation. Based on sensitivity analysis, elastic modules and friction angle have the most influence on ground surface settlement. For example, changes of the friction angle from 24 to 40 will change settlement from 51.3 to 14.7. Also, changes of elastic modules from 75 to 215 will change settlement from 23.2 to 8. Based on these finding, changes of these two parameters in 9 different sections on tunnel route were verified settlement in numerical method with instrumentation settlement. Result shows that increase elastic modulus in numerical models about two times provide good result. Friction angle changes between 37 to 40.

Since the demand in air transport system has the most influence on increasing prosperity and efficiency of this system, identifying the factors that attracts the passengers to air transport is essential. This topic has got an importance in developing countries in recent years because of the slow growth rate of number of domestic flight passengers. In this research which surveys the effective factors on demand of domestic air transport, for gathering required information from passengers, a questionnaire was designed including 20 effective parameters on air transport demand based on consulting experts, university professors and past research studies. It was asked from the passengers to rank the parameters according to their importance. These parameters were categorized using “Factor Analysis” with 6 factors of “cost”, “services”, “time”, “application of up-to-date technology”, “satisfactory and secondary services” and “safety” respectively. Obtained factors were 67.7% effective on changing passenger demands of domestic air transport. The factor “cost” has had the greatest impact with 20.4 %. “Structural Equation Modeling” has been used for checking the “Factor Analysis” results. Modeling results proved the correctness of factor analysis. Furthermore, the modeling has showed that the most mutual effectiveness has been between the factors “cost” and “services” with the value of 0.18. The results of this research express practical implications for airport Companies and airlines in the field of programming air transport, increasing demand attraction of passengers and eventually improvement of economic conditions at a national level.

In this paper, a simulation-based optimization approach is proposed to solve train scheduling problem in single-line and double-track rail networks. In the proposed approach, the simulation model is used to generate feasible train timetable. The simulation model is designed in an object software environment called Enterprise Dynamics (ED). The input data of the problem includes the type of blocks, the order and location of the stations, the number of lines and platform inside the stations, the station facilities (dewatering, refueling, and prayer room), maintenance intervals and praying intervals. The decision variable is the departure time of trains from the origin and the objective of the problem is to minimize the total weighted non-planned stopping times of trains. To find a near-optimal timetable, a simulation-based optimization method based on the evolutionary path relinking algorithm is designed. To evaluate the efficiency of the proposed algorithm, the scheduling of passenger trains in the Tehran-Razi route has been performed. The results of the research show that the implementation of the proposed model has led to significant improvement in non-planned train stopping times as against to the current schedule of the Iranian railways. The proposed algorithm is also able to generate a train timetable in a reasonable time according to the intervals allowed for prayer.

With entering container into transportation area, this area has experienced a huge change. However, the imbalance problem between the input and output containers exists in ports until now. This imbalance between import and export of goods has created a problem called Empty Container. In this paper, due to the theoretical and practical issue challenges in the problem, the reposition of empty containers under certain and uncertain conditions of some problem parameters is investigated. At first, a new model of two-objective planning of reposition of empty containers under certain conditions was presented for the first time in the literature. Thereafter, in order to reduce the effects of uncertain parameter fluctuation under various scenarios in the real world, a combinational approach of robust optimization and risk management is used. The reposition of empty containers robust model is presented by considering uncertainty of several problem parameters like demand and supply as well as loading and unloading capacity under three different scenarios which those probable scenarios are determined using risk management method. In order to evaluate and validate the both presented models, the data from Iran maritime port network are used. The computational results indicate the appropriate performance of proposed deterministic model, efficiency of proposed robust model under uncertainty conditions, and also the importance of using robust optimization approach in creating reposition of empty containers robust plans under uncertain conditions.

Airlines liable to compensate the damages caused by the delay and cancellation of flights According to domestic and international regulations. Airlines can avoid responsibility by providing reasonable measures or force majeure. Travelers also can benefit the maximum compensation by providing Actions be conducted by the carrier is known “Wilful Misconduct”. By examining airline bankruptcies this issue we find that bankruptcy could be considered a reason for the delay and cancellation of flights. So with the possibility of delays and cancellations due to the bankruptcy of airlines, Attenuating this as an example of exemptions from liability and intensify of liability Becomes obvious. The studies in this paper and are aware of the possibility of delayed and canceled flights due to airline bankruptcy, bankruptcy could be an excuse for companies, Bankruptcy could be an excuse for companies to recognize it as force majeure or necessary measures to prevent it, be exempt from liability And could be as Wilful Misconduct applicable to tighten liability, compensation of passengers flying for more support.

Exponential increase of urban population and increasing use of vehicles have created problems for residential areas. Security and calm level and traffic calming, nowadays, is one of the significant subjects in urbanization and urban transportation programming. Urban design seeks to improve environmental quality in order to improve the quality of life of people. A major goal of urban design, especially in centers, is to reduce automobile dependence in order to address issues of viability and sustainability. Urban transportation is also of particular importance in the process of urban design expertise due to its high surface coverage in urban areas. Inner transportation is a part of the transportation system, which, with the aim of providing access between different uses within the boundaries of a city, carries out the movement of human and goods between the adapted spaces. Urban transportation serves as a very important user for all other uses in meeting the needs of the people. The main goal of the present research is to investigate the quality of transportation within traditional neighborhoods for the application of effective and consistent strategies. The research methodology used is an analytical-interpretative review that first starts by studying the outstanding sources around the main subject of the research, through to achieve a targeted framework. In the next step, using the space syntax technique helps to discuss the situation of the case model configuration to achieve clear and effective policy for future actions. The results of the research shows that the main structure of traditional neighborhoods is due to adaptation to different and diverse spaces with spatial continuity and functional-physical connections that according to urban design action (traffic Calming), can injected dynamic and livability’s too this target area.

For example Population increase and transportation development inside cities have been caused traffic and environmental pollutions and consequently caused many economic and social issues. City experts and managers consider using efficient transportation systems as one of the best methods to solve these problems. Since construction and setting up of a public transportation system needs spending a lot of money, selecting the best public transportation system in cities so that includes all economic, social and environmental prospective needs more precise investigation and evaluations. This paper, with recognition of important parameters which effects on selecting the transportation systems, ranks different transportation systems using TOPSIS Multi-Criteria decision making method based on transportation system experts and specialist viewpoint and offers city planners and managers a proper and comprehensive model to choose public transportation system. In this research, to rank the systems, questionnaires have been distributed between experts and specialist. The collected related data recognized criteria's have been used for ranking and prioritizing the public transportation systems in city of Tehran. By using the proposed model, "Subway System" has been selected as a best transportation system in the city of Tehran, meanwhile based of Transportation and Traffic Organization of Tehran; only 16.4 percent of daily passengers are using subway in the city of Tehran. But in recent years investments in subway significantly increased that shows planners and city managers are well aware of this topic.

In recent years, new technology was developed as a warm mixed asphalt in the construction industry. The main purpose of the production of these mixtures, reduce emissions and energy consumption is less in line with the Kyoto agreement. In addition, other benefits such as the ability to apply pavement in cold weather, pavement construction seasons to expand, improve efficiency, faster reopened for traffic after construction, reduce harmful emissions and reduce the risk to workers due to the aging of bitumen production will decrease in temperature. Despite the benefits of attending the pavement, he encouraged the use of this technology, but different aspects of behavior of this type of technology is still not clearly defined. One of these behavioral aspects, potential rutting and moisture-sensitive long-term performance of pavements constructed with in warm mixed asphalt technology. If crumb rubber asphalt are made of warm asphalt mixtures, rubber asphalt construction cost for construction of asphalt rubber asphalt at lower temperatures less. Concomitant use of rubber powder and warm additive to improve long-term performance and potential rutting and moisture sensitivity compared to conventional asphalt mixture. In this study, Laboratory investigation of resistance of warm mix rubberized asphalt containing anti-stripping agent against moisture damages. The results of moisture sensitivity show that the best amount of additive zycotherm in is containing 0.1 percent in sample. The results of resilience module and dynamic creep experiment also show that the most resilience module and dynamic creep for additive Zycotherm in is containing 0.12 percentage for sample which is better than the example sample. Generally, increasing anti-stripping agents warm mixed asphalt will improve moisture sensitivity and rutting resistance of rubber asphalt.

With thriving the sea transport market and the increasing use of container, many containers tend to coastal port. The most controversial concerns of the port can be addressed as the lack of space for storage, high cost of land and lack of proper accessibility to origins and destinations due to traditional transportation of commodities. The best solution to tackle with the mentioned issues will be the concept of dry port as a hieratical transportation, with determined capacity and appropriate distances to port and origin-destination of Commodity. In this research, hieratical dry port location problem with hub location approach has been studied. The demand parameter is assumed as uncertain parameter in the presented model due to more adaption with real world situation. Uncertain parameter concept is considered in this paper to have a mathematical model with robust output under parameter variations. Robust optimization scenario-based model can produce feasible and optimal solutions under parameter variations. The obtained result from presented mathematical model for coastal-port location problem indicate to possibility of establishing 3 coastal-ports in Kerman, Fars and Khorasan-shomali. Also, the validity of the proposed model is presented. At last, results demonstrate to 31% outperformance of presented model and productivity of output robust model.