فصلنامه جاده
سال بیست و ششم شماره 4 (پیاپی 97، زمستان 1397)

As a main mode of transportation, the role of walking cannot be neglected. In order to achieve clean transportation and sustainable urban development in metropolitans, such a matter is of utmost importance. Moreover, the presence of pedestrians helps to enhance the urban safety and increases the cultural interactions. However, in most cities of Islamic Republic of Iran, the infrastructures are built merely considering the needs of the vehicles and almost no attention is devoted to the needs of the pedestrians. Such neglect leads to a decrease in walking and the use of public transportation which in turns can result in a vehicle-centered city, as more and more pedestrians resort to driving personal vehicles. It is obvious that such a city would face safety problems considering the pedestrians. Considering this status, the current article summarizes and describes the possible available strategies to improve the city infrastructure and enhance the pedestrian safety.    

The performance of traffic signal is to develop phasing plans that reduce delays while maintaining a high level of safety. In the signalized intersections and among various feasible movements, “left-turn” is the most complex and time-consuming, which can operate as a protected movement, a permitted movement and a combination of protected-permitted movement. The compilation of the required data for a significant number of variables for calculating the left-turn capacity at the signalized intersections is not possible by the time-consuming way Highway Capacity Manual (HCM) method and is not feasible for rapid decision-making. Therefore, identifying variables more effectively and finding a quick method in this regard is a research issue. So the main objective of this study is to investigate the factors affecting the left-turn capacity and it proposes a simplified model with the fewer number of variables rather than the material of HCM to determine left-turn volume. In this research, data of two signalized intersection in the city of Isfahan, Iran have been used. With these information’s a simplified single variable logarithmic model is proposed to determine left-turn capacity based on following factors opposing volume, number of lanes and percentage of green time. This model estimate critical left-turn capacity for protected left-turn phasing. To validate the objective model, a comparative assessment is carried out taking computational relations of HCM into account. At the end of the research the modeled intersections are simulated by AIMSUN software and the left-turn capacities are obtained in permitted phasing given various indices.  

This research has been done to investigating the effect of three type of metallic swarf including Iron, cast iron and aluminum on asphalt mixture parameters, rutting resistant and the friction coefficient of the asphalt mixtures. In this regard, the amounts of 5,10,15,20 and 25% of each afore said swarf are added to the asphalt mixture and after compacting, the amount of stability, flow, void in the mineral aggregate and void filled with asphalt, unit weight, asphalt binder content and air voids was measured using Marshall Test Equipment. It should be noted that in addition to measuring the above parameters, the Hamburg wheel track test and the friction resistance test were performed to measuring the rutting stability and friction coefficient of the mixtures, respectively. The results of Marshall tests showed that the addition of metallic swarf, especially iron and cast iron, had a positive effects on Marshall parameters, but in different percentages, these additives  had a different performance on changing the Marshall parameters. The results of the wheel track test showing that the addition of 5% iron and cast iron has a positive effect on reducing the depth of the rut , but the increase in the percentage of these additives has a reverse function and increases the depth of the rut relative to the base state. Finally, the results of the friction resistance test showed that the addition of metallic swarf increases the frictional coefficients.  

Concrete pavements are performing the as asphalt pavements. Their skidding resistance level eventually reduced by the flow of traffic, environment, climate change, pollution etc. During their service life. Cause of many road and highway accident, especially in wet condition is lack of skid resistance. Surface of the road must always have a proper texture, which includes both micro texture and macro texture. Mechanical retexturing treatment is about correcting skidding resistance level of the road that improves the return of any leakage of resistance, texture depth, or both. Most of the processes can be done at any time of the year in the toughest weather conditions. These methods can be used as a short to medium term remedial tool for repairing high risk sites and many processes can be replicated. The most appropriate technique to be used in any situation depends on the nature of the level and the downtime that needs to be addressed. All methods for reducing skid resistance are different, and the choice of technique should always be done according to the quality and the specific nature of the procedure. In this paper different methods of re-texturing have been analyzed and place of their usage have been materialized.    

In this research, the risks that can influence the development of an optimal transportation model were taken into account to present an optimal public transport model that considers risks. This is an applied desk and field research. GAMS were used for modeling and solving the model. The mathematical model is a combination of passengers and means of transportation and involves risk planning associated with the means of transportation in the system which should be used by travelers who are in known geographical locations and each require a specific service. At the same time, a time limit for service and a certain late payment are defined for each customer. The means of transportation in the system are different in terms of speed of transportation, cost per time unit, and their ability to travel to the customers' locations. At any time, each mean of transportation can transport one passenger and must return to the origin for the exchange of passengers. The objective function of the proposed model includes the optimal allocation of cost and risk minimization of passengers, as well as determination of the optimal routes for each vehicle, and is aimed at minimizing the costs of transportation, service and latency. An applied example is presented at the end.  

Always, controlling Emission Rate of air pollution has been paid attention with environments economic. For this it has been introduced some national and international agreements. Also, mechanism of controlling in these agreements has evolved during the years. The last one is Kyoto protocol. In this agreement it is designed a clean development mechanism. This mechanism provides cooperation of different countries for example developed and developing one in fuel efficient projects. Land transportation is one of sectors with high fuel consumption and as a result pollutant of it is highlighted. In this paper it is order the use of this mechanism in Iran road transportation with helps of Meta Analysis and also in filed investigation. As a result, with different scenarios, in all modes of transportation the potential of decreasing is estimated between 12.56 to 62.8 million tons yearly. This potential for only road transportation is approximately between 5.16 to 25.8 million tons. Furthermore, in the same situation with investigating feasibility study of rail projects it is known that road transportation pollute more than 124 times in passenger and 413 times for freight in comparison with rail.                                        

In the most of practical and industrial fields, specifically Civil engineering, important multi-criteria decisions have a fundamental impact on the seeking result. One of the popular methods for dealing with multi-criteria decisions is “Analytic Network Process” also known as ANP. In this paper, we try to choose the best tunneling system for the 2nd line of Mashhad subway, between the three alternatives: Cut & Cover, NATM, and TBM, using the above mentioned method and with taking environmental criteria into serious consideration. The results of this research indicate that decision-making and management methods like ANP can provide reliable and rational outcome, according to the approach we take (e.g. environment in this paper) and help optimizing any assessment process. Also, the results indicated that the technology TBM is preferable and reasonable between the three alternatives and has a reliable performance under most criteria except cost and land use related criteria.    

The purpose of this study is to provide a model for predicting the dry density of the clayey subgrades stabilized with Portland cement and iron ore mine tailing (IOMT) materials. For this purpose, Portland cement with 0, 6, 9, 12 and 15% and iron ore mine tailing with 0, 10, 20, 30 and 40% was added to clay soil, and then the compaction test was performed using modified proctor method on 25 different compounds and a database of 125 records was prepared. Then, using a response surface method (RSM), a model was proposed to predict the density of the clay subgrade stabilized with IOMT and Portland cement. Input variables in this model include moisture content, percentage of iron ore mine tailing and percentage of Portland cement, and the output variable is dry density of the stabilized clay soil. The regression coefficient of the developed model was 0.9634 which indicates the high accuracy of this model. Also, the predicted R2 (0.9416) indicates its logical compatibility with the adjusted R2 value (0.9551), with respect to a difference less than 0.22 among them. Finally, based on the developed model, two diagrams were developed to predict the maximum dry density and the optimum moisture content of clay subgrade stabilized with Portland cement and iron ore mine tailing. Regarding the results of this study, it is possible to predict the optimum moisture content as well as maximum dry density of the clay subgrade with low plasticity stabilized with Portland cement and iron ore mine tailing.

The main purposes of this article are to evaluate the productivity of Tehran Metro transportation system. To meet this ends, the data of Tehran metro transportation system over the periods of 1387-91 were used. Moreover, the data envelopment analysis (DEA) method was used to measure total factors productivity by Malmquist indexes which have resulted from technical efficiency and technological changes. Also, in this study sought to evaluate the progress and recession rates of productivity in each metro line on two steps. The results indicated that in the first stage, there was only one line with increasing productivity, and in the second stage, all lines have increased productivity in the early years, but over time, fluctuations in productivity were observed. On the other hand, in this transportation system, the ratio of technological changes to productivity was more than the ratio of efficiency to productivity. So to increase metro lines productivity, it is necessary to improve technical efficiency and scale efficiency.  

The present article discusses the responsibilities of the air carriers regarding the arrival of the damage to the passenger and goods, or the delay in passenger flight and arrival of the goods. Issues about the regulations relate to these cases and the defenses that the air carrier can make in these cases will be analyzed in domestic and international flights. This article covers the analysis of the Warsaw and Montreal Convention, because it relates to international flights and domestic regulations related to the discussion of domestic flights. The basis of responsibility is the strict liability and the regulations of the Warsaw Convention can also be applied in domestic law, and the cases of exemptions in addition to force majeurem, is pass of time barred of lawsuit.  

In present century the air transportation has had a very important role in relations between different countries of the world , as exchanging of culture, showing the economic and military power and speeding the vital affairs of a country and in this case airports form a very critical role in the Air Transportation system. In fact airports are considered to have the most basic role in Air Transportation industry. The main aim of the present research is to analyze the location of the Shahid Beheshti International Airport in Isfahan using analytical methods, field (observation) studies, and interviewing technique along with a questionnaire and the model of the factor analysis and standard indicators of the International Civil Aviation Organization (ICAO). The results determine that the airport's proximity index to military air base explained with 26.49% of the variance was the most important airport problem from participants’ viewpoints. In addition, the index of non-observance of environmental indices, distance to the city of Isfahan and the proximity of the airport to industrial areas are other important indices that are considered.  

Red-light running (RLR) is considered as a highly dangerous driving act. Reducing this risky behavior depends on understanding its prevalence, as well as the drivers which are involved. This study investigates the video images of traffic cameras and central smart program in four intersections of Qazvin. Peak and off-peak conditions were assessed in either sunny or rainy weather and drivers' behavior in red times was studied using binary logit model. It has been considered that red light running is often occurred unintentionally. Generally, according to the observations, 96 percent of red phase violations are happened during the first two seconds. Recent studies have concluded that drivers’ decision to stop or cross the red light is complex but can be reasonably predicted based on numerous factors (e.g. number of pedestrians in streets and time passed in red phase, etc). Vehicle’s speed is another significant factor which highly effects the crossing probability during red phase. Moreover, in situations where vehicles` distance from the intersection is more than 20 m at the onset of a yellow-phase, the passing probabilities are zero percent and if vehicles’ distance from the intersection is more than 9 m, red light running probability will be 51 percent (Other variables considered as their average).  

Transportation sector is an important sector of economic which has many effects on other sectors of economic. Operation of this sector is dependent to energy and energy price changes are affected on value added and inflation of this sector and have important effect on main variables of economic. In this paper, effects of volatility of energy price are surveyed on value added and inflation of land transportation sector and its intensity on these two variables with VECM, Impulse response. Results reveal indirect effect of volatility of energy price on value added and direct effect on inflation in land transportation sector. Second hypothesis as more effects of volatility of energy price on inflation respect to value added in this sector, is accepted.  

Today, air and rail transportation are two important industries in the world, because they effect on the economic, cultural and social issues of societies, causing the cities to communicate to each other, and in the larger space, they lead to the relationship between countries. In other words, they lead to the society growth in all economic, cultural and social themes, and sometimes affect the tourism industry negatively or positively. In this research, a simple of Iran provinces have been investigated during the period of 1399-1389. The research method consists of two Granger causation and panel data methods. The results indicate that the relationship between aviation, rail transport and tourism is a one-way relationship, and due to the lack of priority tourism in development plans and the lack of adequate subtraction for airial and railing transportation, subtraction the expectation of direct communication, the results indicate an indirect communication. Also, to measurement of the aviation and rail sectors productivity of the selected provinces it has been used from the input-to-input ratio. According to the obtained results by calculating the average of each province during the period of 1394-1389, in the gross production ratio to the number of rail passengers, Tehran province has the highest measure in the GDP. In the ratio of gross production to rail arrived freight, Tehran province has the highest measure in the GDP. In the ratio of gross domestic product to the number of transported air passengers, Tehran has the highest measure in the GDP and In the ratio of gross production to the air carried freight, Markazi province has the highest measure in the GDP.  

Footpaths are among the most important public and urban spaces, and their importance is due to their function as part of the urban transport system as well as its function as an urban space. The existence of a sharing between the walking system in urban transport and urban planning requires a collaborative work for different planning and design stages. The main objective of this research is to determine the optimal timing of traffic lights by examining the behavior of pedestrians at intersections and their interaction with vehicles at one of the most important intersections of Tehran. The minor objectives include calculating the traffic parameters associated with each type of traffic facility, simulating pedestrian behavior by software and programming in order to determine the optimal timing of traffic lights.  

The existence of dispersive soils in civil project is regarded as one of the geotechnical problems. This research studies the engineering properties of dispersive and improved soil. Studied soil is located in Dispersive- semi Dispersive range. In the current study, first, the disparity potential of studying soil (Minab city in Hormozgan province) was evaluated by double hydrometer, crumb, pinhole and chemical tests. In the following, Dispersive soil was mixed with red soil of Hormoz Island and cement, and after the 14 days curing, the test was performed on samples and finally dispersivity changes and soil plasticity were studied. The results showed dispersivity is greatly decreased, because of existence of Fe+3 in Red Soil and Ca+2 in cement. In addition, Plasticity index is increased in improved samples with increasing cement and the red soil. According to the results of pinhole test, adding 10% of red soil and according to double hygrometry 10% of red soil in addition to 1.5% of cement would result in the elimination of dispersivity potential.  

Nowadays, the existence of limitation in urban spaces, the requisiteness of consideration to land use from the environmental and social perspective, as well as the necessity to develop the urban transportation network, has forced those involved in urban management of cities to use underground spaces as one of the best alternatives. The usage of these infrastructures in developed countries, has led to the very well results on reducing the traffic and urban transportation issues, which unavoidably necessitates their application. On the other hand, the potential of the occurrence of hazards and incoming risks on tunnels has always been considered as the main challenge of tunneling in each three phases of design, construction, and operation, and with regard to the remarkable costs related to construction and operation of these establishments, the identification of these hazards and investigation of their impacts on tunnels has a particular importance on reducing the probable damages. In phases of design and construction, the investigation of types of hazards on urban tunnels shows that hazards such as the occurrence of mistakes in planning stage such as preparation of technical specifications and estimation of design parameters; computational and numerical mistakes; managerial and controlling mistakes; the occurrence of errors and mistakes during the construction phase of tunnel; hazards due to unknown situations of underground spaces; the existence of underground water; entrance of water and flood; effects of earthquake on tunnel; and hazards due to subsidence as well as the gases must be considered in the risk management and securing the safety of urban tunnels.