پژوهشنامه حمل و نقل
سال بیستم شماره 1 (پیاپی 74، بهار 1402)

Due to the sharp reduction in budget of civil projects and road construction, the need to use local soil as the base is felt as a way to reduce the final cost of projects. Therefore, this research examines the characteristics of untreated and treated base soil with 3% lime, including uniaxial compressive strengths and indirect tension (Brazilian) test and resilient modulus with different curing times, as well as after performing tests of wet -dry cycles and freezing- thawing. Uniaxial and Brazilian samples with a diameter of 10.1 cm and a height of 11 cm were made in 3 layers with the same thickness and dry density of 2.2 g/cm3 and initial moisture of 6% and 8%. The results show that the addition of lime significantly increases the CBR values and shear strength of the soil. Soil treatment with lime improves its resistance against wetting-drying cycles, but it is not suitable against freezing- thawing cycles. Also, based on the tests to determine the resilience modulus, a comparison was made to determine the relationship between CBR values of untreated and treated soil with lime under hot-dry weather conditions. The results showed that the modulus values of dry untreated soil and lime treated soil are equal. The CBR value (maximum value based on penetration of 2.5 mm or 5 mm) in untreated soil is equal to the same value for penetration of 1.25 mm in lime treated soil. Therefore, for design purposes, it is recommended to use correlation relations of resilience modulus and CBR values for penetration of 1.25 mm for soil treated by lime.

After The Emergence of the COVID-19 Virus, Beyond the Inappropriate Aspects of the Contagion of the Virus, the Effects on the Global Society Have Been Appeared. Changes in Mental Health, Social Relations, Lifestyle, Transportation, Income, Living Motivation, Etc. Has Been Investigated in Various Researches. in this Study, the Effects of COVID-19 Contagion on Changes in Traffic Volume, Modes, Air Pollutions Such as Particulate Matter (PM), Sulphur Oxides (SOx), Carbon Monoxide (CO), and Nitrogen Oxides (NOx) For Karaj-Chalus Corridor, is Investigated by SPSS Using Pearson Correlation and Cross-Correlation, And Multivariate Regression. in Addition, the Effects of Control and Management Policies Against Corona Virus Contagion on Each Aforementioned Parameters Were Evaluated. the Results of this Study Showed That, During the Peak Period of the COVID-19 Contagion, the Traffic Volume is Accompanied with A Significant Reduction as Well as the Amount of Generated Pollutants. However, After A Short Time Elapsed Since the Peak of Both the Contagion and the Lockdown, Traffic Volume Increased Even More Than Pre-COVID Period. Moreover, the Analysis of Transport Mode Changes and The Heavy Vehicles' Pollution Showed That Traffic Restrictions and Fines for Non-Domestic Passengers, Despite Higher Risk of Infection, Augmented The Interest of Travelling with Suburban Buses. Cross-Correlation Analysis Showed After 20 Days of Entering Higher Amount of Vehicles to Mazandaran District, Covid Cases Increased Respectively.

The urban subway network is one of the most vital infrastructures that plays a pivotal role in the sustainable development of cities; therefore, network robustness or maintaining the proper performance in various conditions has great importance. Considering financial and functional limitations, identifying critical nodes is required to prioritize robustness enhance projects. Critical nodes are nodes that their removal deeply affects the connectivity and efficiency of the network. Network robustness and identification of critical nodes in the face of cascading disruptions have been studied, focusing on the network's structural features. On the one hand, cascading disturbances affect several stations simultaneously, which is less likely to occur than concentrated disturbances that affect only one station. On the other hand, focusing on the network structure leads to the loss of dynamic information, resulting in underestimating the length and overestimating the number of paths between network nodes. In this study, the critical nodes in the face of centralized disturbances have been identified using temporal network concepts, which consider both structural and temporal features. The results reveal that Darvazeh-Shemiran, Shadman, Shahid Beheshti, and Mohammadieh Square stations are the critical stations from both efficiency and connectivity points of view. The critical nodes have high values of static and temporal centrality indices, which increase network vulnerability against malicious attacks. In contrast, due to the high ratio of non-critical nodes to critical nodes, the network is robust against random failures. The method developed in this research can be generalized to other transportation networks.

One of the influencing factors in failure asphalt layer perecentage empty space. For that reason validate benchmark for assessing and evaluating the quality of asphalt in road projects. Coring is the usuall method for measuring quality of asphalt layer in the implemented road projects. But the mentioned method is costly and time-consuming and also show the quality of asphalt layer in a specific point . In the present article determin percentage empty space and also detection potential failure of the implemented asphalt layer with using the device GPR ( Ground Penetrating Radar ) reviewed. In the research firstly a part of Tehran network roads selected as a sample for study then evaluated mechanized with the help device GPR done . In the following taken core samples from locations rand omly and then experiments determine percentage empty space and density done on them.In comparison results destructive experiments with mechanized scrolling transpire by increase percentage empty space in the asphalt layer decreases dielectric. So that by decreasing the percentage of empty space less and equal to 9%, an increase in dielectric constant value of 5 due to non-destructive evaluation observed. .so the using output results radar can be obtained continuous profile from status percentage empty spase the project study that this profiles obtained make useful in diagnosis potential groove failure implemented asphalt layer.

Wagons are one of The Valuables Assets in Railway Networks. Boosting Trade Speed which caused by Exact Wagon Tracking, In One Hand Acquire Customer Satisfaction in Supply Chain and in Other Hand Result in Decreasing Capital Cost and Increasing Productivity then Finally Make Railways Investment justified. We Aim to introducing The Current Procedure in Fleet Tracing, Advantage and Disadvantage of Each Methods, Calculate the Cost and Effect of Humane Errors, Necessity of Implementing Modern Methods for Wagon Tracking and Eventually Determine the Best System of Wagon Tracing in IRI Railway Network by means of Concordance Analysis Approach. For This Purpose, We measured Five Options in Twelve Criteria’s. It is Necessary to Mention that This Research in Context of Automatic Wagon Identification is Novel in the Country and yet not to be done. The Output of The Study Show That Installing the GPS Module on Each Wagon is the Best Method for Wagon Automatic Identification in Iran Railway Network.

Regardless of the properties of links and junctions, road network structure and their arrangement effects on traffic safety and this is a topic that has been less discussed in the area of traffic safety. In this study for the first time in the country by defining a quantitative indices of street network pattern, its impact on the risk of traffic accidents has been observed in 178 Mashhad's Traffic Analysis Zones (TAZs). For this purpose, with using Mashhad's crash data of 2008-2010 years, the Space Syntax measures such as Integration, Connectivity, Choice, Entropy, Intelligibility and other descriptive variables such as average car ownership, vehicle kilometer traveled, number of junctions and road network density, The Bayesian accident prediction models were fitted to data. Poisson Log-Normal model was developed to investigate and compare the ability of Space Syntax measures in improving crash prediction models and the BYM model with Conditional Autoregressive (CAR) prior was used to incorporate the spatial correlation of nearby zones. Finally the risk of traffic accidents was estimated using the selected final model. The results showed that applying the descriptive variables of the road network pattern leads to the improvement of crash prediction models. The performance of the Connectivity measure was better than other quantitative variables of the road network pattern and considering the spatial correlation of the TAZs improved the predictive power of the model. The results indicate that the Integration, Connectivity and Intelligibility measures are directly related to the risk of accidents while Entropy and Choice are inversely related. This means that by changing the road network pattern from Irregular to Grid, traffic safety is decreased. This achievement can be used to design a new road network with more safe design of network pattern.

Autonomous Vehicles (AVs) provide safe and efficient mobility without human intervention by using self-propelled and communication technologies. This technology will be a turning point in transportation. Evaluating the acceptance of AVs plays an important role in its successful and efficient use. Removing economic and technical barriers without removing the human barrier will be not efficient. Most researchers have used Unified Theory of Acceptance and Use of Technology (UTAUT) in order to identify the latent variable affecting the acceptance of AVs. In this study, in addition to the variables considered in this theory (including performance expectancy (PE), effort expectancy (EE), and social influence (SI)), the perceived risk (PR) variable is used to identify more latent variables affecting the acceptance of AVs. In order to calibrate the structural equation model proposed in this study, 641 stated preference questionnaires were distributed among the residents of Tehran. The results indicate that the variables of PE, PR, EE, and SI influence on the acceptance of AVs, respectively. The results of this study can be used by decision-makers and policymakers to evaluate and estimate the response to AVs before the start of development and adopt appropriate policies to increase the penetration rate of these vehicles.
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Traffic safety issues due to speed increase accompanied by the rapid development of freeway and highway systems have increased the concern of the people and transportation policymakers. Speed limitation, as one of the most common safety measures, plays a unique role in protecting passenger safety. Thus, the study of traffic control effect by applying the speed limit on roads (especially freeways and highways) is scientifically significant to ensure passenger safety and functional performance. In this paper, by using time series method, road accidents in Tabriz-Zanjan freeway in design year (presence date of the speed cameras) have been predicted. Then by comparing the anticipated results with the real data, the impact of speed cameras on this road has been investigated. Before the modeling process, data collection, recording, framing and normalization operations were performed by Excel software and IBM SPSS software was used to construct the time series model. After comparing design year's data and examining the impact of cameras on this freeway, the number of fatal accidents decreased by 76%. The impact of speed cameras in reducing the number of crashes was negligible by 5%, and it did not have a positive impact on the number of injuries, and injuries increased by 38% this year. by investigation of available data from base year until horizon year, it was observed that upgrading road safety has been possible by adding appropriate designs and the speed cameras on this route have had an acceptable performance, and all three parameters (number of crashes, deceases, and injuries) have gone through a decreasing trend.

Increasing the number of vehicles on the streets is called the problem of urban traffic congestion. One way to solve this problem is to control the timing of traffic lights. In this research, the model used is the green-red space model and the yellow light as a third color has been added to the modeling. To control the illuminated intersection, a fuzzy amplifier-learning controller is used, the core of which is the Fuzzy Q-Iteration algorithm. The length of each street queue is considered as a fuzzy variable. The controller generates a control signal according to the length of the queue behind the light. The output control signal is the duration of the green light on each street during a cycle. The results show that the proposed controller had a similar or better performance than the fixed time controller ratio with the vehicle waiting time criterion. At high input current rates, controller performance has improved significantly in reducing waiting times. In addition, the queue length on streets with high input flow rates is reduced because the agent tries to generate a larger control signal on high flow rates streets, which means more green time for that street. According to the proposed model, the number of cars on each street of the smart intersection does not exceed about 30 cars.

Ports always play a strategic role in the development of a country's domestic and international trade, whether it is developing or developed. Ports as a base of maritime trade have changed a lot in recent decades, but in line with these changes, the Ports and Maritime Organization, as the main custodian of port and maritime policy, must adapt quickly, and this adaptation and the process of change in the next generations of ports of the country should lead to good governance in the management of port affairs. The present study is a descriptive-survey research in terms of applied purpose and based on its nature and method. This study identifies the effective factors on good governance in the Ports and Maritime Organization by comprehensively reviewing the existing literature and then using fuzzy Delphi method to refine the components based on the opinions of experts and then analyzing the relationships between the components of good governance using the Fuzzy Dematel technique. Findings show that the component of "Responsibility" has the most impact,influens and most of the interaction and communication with other components is among the other components of good governance.

The aggregates as a prominent part of concrete mixture have significant impact on durability and strength of concrete pavements. One of the most important problems attributed to some part of aggregates in Iran are reported to possibly deleterious alkali silica reaction between the hydroxyl ions (OH−) in the pore solution and reactive silica in the aggregate over the time. So, investigation of alkali-silica reaction potential for aggregate in this area in addition to identifying appropriate preventive measures to minimize the risk of expansion is so invaluable because of high consumption of these suspicious materials in the construction of concrete pavements.This study presents evaluation of alkali silica reactivity potential of Mazandaran and Guilan aggregates using petrography examination of aggregate according to ASTM C295, alkali silica reactivity mortar bar testing according to ASTM C1260 and determination of length change of concrete due to alkali silica reaction according to ASTM C1293. Selecting appropriate preventive measures to minimize the risk of expansion when deleterious reactive aggregates are used in concrete pavements are described in following. Based on results obtained in present study, it was observed that about 30 and 50 percentages of aggregates placed in two studied province of Mazandaran and Gilan respectively, has high alkali silica reactivity. Furthermore, preventive measures including limiting the alkali loading of the concrete to 1.8 kg/m3, substitution supplementary cementitious materials such as silica fume to amount of 7%, or a combination of these strategies was suggested for use of high alkali silica reactivity aggregates in concrete pavements.

Today, the method of Build, operation and Transfer of accepted and effective methods for investing in the construction of fast infrastructure projects required by countries. However, several risks may affect the Build, operation, and Transfer contracts.One of the most significant topics in study of BOT is process of its allocation to public and private sections. In this paper, by presenting the position of the risk-sharing process in the formation of Build, operation, and Transfer projects, a guidance framework is developed for how to allocate risk among the project's agents.Therefore, before starting a project and contracting, each of the project risks must be determined according to the appropriate criteria. Study continues by studying risk’s allocation in two quantitative and qualitative levels. Qualitative model uses Bayesian model to allocate risk for employer and contractor in 93.56% and 98.31% levels of significance. In order to identify the risks in the high way project of Tehran-Rasht, we first used 30 action questionnaires and then qualitative assigning and sharing the risk. In quantitative model, game theory used to allocate minimum of total cost while 35% of risk assigned to employer and 65% to contractor.

Because of the advantages of the railway transport like less accidents, energy consumption and environmental pollution, Iranian government pays special attention to this mode of transportation. However, the Iranian Railways (RAI) has not yet been able to gain its share of the freight market. As one of the main elements of the marketing mix, pricing plays crucial role in increasing the share of railway in the market and adopting the right and timely strategies in this regard can lead RAI to achieve its grand goals. In this study, the most important internal factors (strengths and weaknesses) and external (opportunities and threats) of RAI in the field of business and especially price identified by studying the literature review and interviews with rail transport business experts, then strategies in this field were identified using SWOT technique. In the next step, the identified strategies were prioritized by using QSPM technique. The results show that developing the brand, improving customer orientation, get government subsidies for the social benefits of railways and increasing market share through the developing a pricing model, are presented as the top-priority strategies of the RAI that can take the initiative in freight transportation pricing.

Pavement is the main part of the country's road network. Therefore, the evaluation of pavement conditions, especially the inspection of pavement distresses has an important role in the managing and repairing process of the pavement network. Bleeding is one of the important distresses in asphalt pavement because it has a direct influence on pavement skid resistance, vehicle maneuverability, and road safety. According to a survey of prior research, the automatic evaluation of bleeding receives less attention than other pavement distresses, and the main focus of study in this field has been on the automatic detection of bleeding. Automatic segmentation of distress regions is a critical component of pavement distress evaluation, allowing for a more precise assessment of distress. As a result, the purpose of this study is to develop an efficient method for the automatic segmentation of bleeding regions from healthy regions using image processing tools based on multiresolution image analysis. The proposed method has better performance than prior research, with averages of 82.44, 88.66, and 80.33 percent based on recall, Dice similarity coefficient, and intersection to union ratio as prevalent segmentation performance metrics. This model allows for the automated evaluation of bleeding and can enhance the performance of pavement management systems.

Predicting the viscoelastic properties of asphalt mastic is very important in pavement engineering. Prediction of viscoelastic properties of mastic using machine learning methods resulting in closed form formulation is not considered in the technical literature up to now. This study aims to develop prediction models for complex shear modulus (G*) and phase angle (δ) of modified asphalt mastic with Styrene-Butadiene-Styrene (SBS) at low and medium temperatures. Three different amounts of SBS (2, 4, and 6%) are considered for bitumen modification and four different volume filling rates (10, 18, 25, and 35%) are considered for making asphalt mastic samples. Dynamic Shear Rheometer (DSR) test was performed in frequency sweep mode at 21 loading frequencies from 0.1 to 100 Hz and seven temperatures of -22, -16, -10, 0, 10, 16, and 22 ° C. This test was used to measure the G* and δ of samples of asphalt, modified asphalt, and asphalt mastic. Multi-gene genetic programming has been used to develop the G* and δ asphalt mastic prediction model based on the additive's dosage, loading frequency, temperature, filler volume filling rate, G* and δ of the base asphalt. Finally, two separate prediction models for G* and δ are developed, with a R2 value of 0.96 and 0.98, respectively. The results show that multi-gene genetic programming can accurately predict the viscoelastic behavior of asphalt mastic. After examining the performance of the models, it was shown that the viscoelastic properties of the asphalt have the greatest impact on the prediction of output variables by performing sensitivity analysis on the prediction models..

Transportation of spent nuclear fuel requires radical and scientific management due to radiation and high temperature. Looking at international documents, in particular the Joint Conventional Fuel Safety Management Convention, which is designed to protect individuals and the environment from damage caused by it. The present paper seeks to clarify and assess the obligations of governments to apply the legal safety requirements for the remaining nuclear fuel and thereby respond to one of the requirements for the development of nuclear energy use. Finally, there are weaknesses in the safe transportation sector, such as the lack of comprehensiveness and universality of these regulations and the complementarity of government responsibilitiesTransportation of spent nuclear fuel requires radical and scientific management due to radiation and high temperature. Looking at international documents, in particular the Joint Conventional Fuel Safety Management Convention, which is designed to protect individuals and the environment from damage caused by it. The present paper seeks to clarify and assess the obligations of governments to apply the legal safety requirements for the remaining nuclear fuel and thereby respond to one of the requirements for the development of nuclear energy use. Finally, there are weaknesses in the safe transportation sector, such as the lack of comprehensiveness and universality of these regulations and the complementarity of government responsibilities.

The development and industrialization of communities, and consequently the birth and development of urban suburbs, has led to a sharp increase in travel demand. This increase in demand, along with the jump in the growth rate of car ownership, has led to the emergence of several problems, such as excessive energy consumption, environmental pollution, traffic delays , and psychological problems caused by traffic The main challenge for transportation policy makers, in addition to providing to respond to the large volume of travel, is to take measures to reduce the above losses. The suburban train is a rail's public transportation system that runs between the distances of a metropolis with topics such as work, education, and business. This system can to play a key role in improving transportation problems and even lead to economic efficiency in the long run. This study determines the extent to which suburban trains can meet the transportation needs and what are the benefits of increasing the services of using this system compared to other methods. The purpose of this study is to evaluate the performance of suburban trains from various economic, social and traffic aspects to highlight the characteristics of this system to take an effective step in expanding the scientific field of this system into enter the cycle of sustainable competition in the transportation of suburban areas. Simultaneous analysis of two lines with different characteristics of suburban areas, explanation of criteria in TOD, increasing the share of personal preferences of users in other criteria are aspects of innovation in this study In this research, using the research method of multi-criteria statistical ,it is argued that according to the set criteria, suburban train By gaining the majority of points defined as the ideal limit, it has the first rank and has the highest level of desirability.

Improving the physical properties of soil using industrial waste has always been of interest to researchers And it becomes more important when Accumulation of huge volume of borrowed Soil resulting from the development of Civil projects Due to improper engineering characteristics For reuse in Civil projects Cause a lot of problems. On the other hand Given that Iran is one of the hubs of steel production and Huge volumes of steel furnace slag are produced and accumulated annually in this country, It is necessary for the optimal recycling of this waste Conduct comprehensive research in various fields of science and technology. One of the goals for the optimal use of this waste, Their use is in soil improvement for use in road construction. The present study is based on the improvement of accumulated fine-grained soil in Mobarakeh Steel area Using processed steel slag in the size of 0 to 25 mm , Has been studied For use in road construction. Engineering properties of loan soil in Mobarakeh Steel Plant (Saba area), Includes Liquid Limit and Plasticity Index , classification and seive size, After sampling from different parts, Preparation and testing in the laboratory Was initially examined According to the specifications of road building materials, Soil unsuitable for use in road construction was identified. Eventually, by performing step by step experiments, Soil engineering properties were modified using different percentages of steel slag And achieve a suitable mixture for use in road construction. Also compare the geotechnical properties of soil samples to the samples of soil and slag mixture obtained Showed that these properties improved significantly by increasing the percentage of slag.

This research evaluated the effect of epoxy resins on the moisture resistance of asphalt mixtures of each bitumen and aggregate (limestone and siliceous) combination by measuring their surface free energy characteristics. The laboratory method measured the contact angle of several probe liquids called the Sessile Drop method. Bitumen polarity, cohesion energy, adhesion energy, bonding energy, energy parameter related to adhesion performance and energy parameter related to wetting performance of aggregate surface by bitumen for each combination of bitumen and limestone and siliceous aggregates were investigated. The results show that epoxy resins increase the polarity of bitumen, but they do not have a positive effect on increasing the cohesion energy of bitumen. For all the studied bitumen-aggregate compounds containing epoxy resin, the adhesion and wetting performance has increased compared to the compounds containing base bitumen, which indicates the proper performance of this additive in improving the moisture resistance of asphalt mixtures.

Despite the significant advantages of rubber powder in the pavement industry, but the significant increase in viscosity and storage stability problems of rubberized binders has led to the implementation limitations of this technology. Accordingly, various methods have been proposed to improve the technical and performance properties of rubberized binders as a complementary additive. The aim of this study was to improve the fatigue and rutting performance of rubberized binders and mixtures using nano-clay. In order to achieve the set goals, rubber binder containing 8% and 14% were modified with 2 to 6% nanoclay values using linear amplitude sweeping (LAS), Multiple Stress Creep Recovery (MSCR), Four points bending beam and dynamic creep tests were investigated.The results of MSCR and dynamic creep showed that the addition of nanoclay up to 4% had a significant effect on increasing the rutting strength and reducing the permanent deformation, but increasing it to 6% reduced its ascending trend. Also, the results of the four-point beam test showed that, due to the positive effect of nanoclay on improving fatigue life and aging resistance, the mixture containing modified binder with 14% rubber powder and 3% nanoclay increased 195% fatigue life compared to the control specimen. In general, the simultaneous study of fatigue and rutting behavior showed that the simultaneous use of 4% nanoclay and 14% rubber powder had the best effect on asphalt performance.

The aim of this study was to investigate the effect of warm mix asphalt additive on the low-temperature performance of bitumen and asphalt mixtures containing rubber powder and gilsonite. In the present study, gilsonite, rubber powder and 2 warm mix additives (3% Sasobit and also 0.3% Zycotherm) were used to modify pure bitumen (AC-85/100). Several bitumen rheological tests and mixed functional tests were performed. The results of rheological behavior test showed that the performance of asphalt bitumen’s at low temperatures deteriorated with the addition of gilsonite, while the use of rubber powder improved the performance of low temperatures. The test results showed that the use of gilsonite leads to decrease the fracture energy and stress intensity factor. While, addition of crumb rubber led to increase them. Based on results, addition of warm mix additives led to increase the fracture energy and decrease the stiffness at low temperatures.

Composite modification is increasingly used to alleviate the detrimental problems associated with asphalt modifiers and meet the massive demand for asphalt pavement. In this study, nano-Al2O3 composite modifications at three concentrations of 1%, 2%, and 3% by weight of asphalt binder were implemented in neat and modified asphalt binders to improve their performance at high and intermediate temperatures. These binders were evaluated in terms of their physical, rheological, and high-temperature storage stability properties. In addition, nano-Al2O3 composite modified binders were utilized in asphalt concrete and investigated for their resistance to cracking, permanent deformation, and moisture damage. The nano-Al2O3 composite modifications were made using neat, polymer-modified, and crumb-rubber (CR) modified asphalt binders. Adding nano-Al2O3 to the asphalt binders was found to improve stiffness, high-temperature storage stability, permanent deformation resistance, and cracking tolerance. Moreover, the composites of nano-Al2O3 with neat and modified asphalt binders were found to provide improved resistance to permanent deformation, cracking, and moisture damage in hot mix asphalt concrete. The composite of 2% nano-Al2O3 showed the best performance in terms of resistance to permanent deformation, the composite of 3% nano-Al2O3 showed the best performance in terms of resistance to moisture damage, the composites of 2% nano-Al2O3 with polymer and CR-modified asphalt binders both showed the best performance in terms of resistance to cracking, and the composite of 3% nano-Al2O3 with AC20 showed improved resistance to cracking.