Research Article
مهندسی عمران-سازه های هیدرولیکی
roozbeh aghamajidi; amir kamanbedast
Abstract
In this study, the effect of change of flow discharge on the scouring around the piers of the fifth bridge of Dezful was investigated using the Hsec-RAS numerical model. For this purpose, a hydraulic model was created from the range of the river in which the bridge is located in the software by using ...
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In this study, the effect of change of flow discharge on the scouring around the piers of the fifth bridge of Dezful was investigated using the Hsec-RAS numerical model. For this purpose, a hydraulic model was created from the range of the river in which the bridge is located in the software by using field data. Then, by entering the data on the scouring of the bridge bases for the discharge of 25 to 1850 m3/s with different time steps, the effect of change of flow discharge on the scour around the middle and lateral piers of the bridge was investigated. The results of numerical model show a trend The increase was such that in low to moderate discharges (329m3/s) the scouring rate around the middle piers had the highest value, but in high discharges and flood conditions the scurry in the right support had the highest value, also up to 1630 m3/s flood conditions, the scouring rate in the left support had the lowest value, which was due to the morphology of the river bed and the Conditions are the creation of secondary currents in the arc.
Research Article
civil engineering
Mohammad Hossein Taghizadeh Valdi; Edris Merufinia
Abstract
In this article, the water entry problem of reticulated pounder including 4, 9, 16, 25 and 64 holes which are distributed with a matrix arrangement on the surface of the pounder, is investigated numerically and to model the interaction between the pounder and fluid, an explicit dynamic analysis was employed ...
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In this article, the water entry problem of reticulated pounder including 4, 9, 16, 25 and 64 holes which are distributed with a matrix arrangement on the surface of the pounder, is investigated numerically and to model the interaction between the pounder and fluid, an explicit dynamic analysis was employed using the Eulerian-Lagrangian couple formulation available in the commercial finite element software Abaqus 6.14-2. The results of the numerical solution were validated by comparing and matching the numerical, theoretical and experimental results of the trajectory of a spherical projectile in the depth of water, including the shape of the air bubble formed and the pinch-off time and depth, which indicated the accuracy and application of the numerical algorithm used. The results of the current research showed that the 9-hole pounder reaches the model bed at a depth of 100 cm in less time than other pounders with different arrangement and number of holes. In 16- and 25-hole pounders, the ratio between the mass of the pounder and the area of the holes is unstable, and due to the decrease in the area of the holes, the effect of water resistance on the bottom of the pounder increases when it moves in its depth. The effect of increasing the mass of the pounder on reducing the duration of its immersion in the water depth is more evident in the 64-hole pounder. So that this pounder has a smaller area of holes compared to other pounders, it has more mass with smaller holes than other pounders, and despite the smaller dimensions of the holes and the increase in the life of the reticulated pounder, which is the factor that increases the resistance of the water entering the pounder floor, due to the large mass of the pounder, it overcomes the water resistance that is applied as an upward force on the bottom of the reticulated pounder, and the duration of its movement in the depth of the water is reduced from the moment it hits the free surface of the water until it reaches the model bed.
Research Article
مدیریت ساخت و مدیریت پروژه
Amir Hossein Dalir; Hasan Javanshir
Abstract
This study evaluates the impact of Digital Twin (DT) technology on project success metrics—specifically time, cost, quality, and safety—within the automated monitoring and control of construction projects. Employing a mixed-methods approach, the research integrates survey data, Structural ...
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This study evaluates the impact of Digital Twin (DT) technology on project success metrics—specifically time, cost, quality, and safety—within the automated monitoring and control of construction projects. Employing a mixed-methods approach, the research integrates survey data, Structural Equation Modeling (SEM), case analysis, and qualitative insights from interviews and focus groups. A novel DT-based Progress Monitoring Management Model (DRX) is proposed and assessed, leveraging reality capture and Extended Reality (XR) technologies to streamline construction oversight. Findings reveal that DT significantly improves project outcomes by automating process oversight. The DRX model emerges as an innovative framework, enhancing construction management through the integration of DT and XR technologies, offering empirical insights into its efficacy and delineating its practical challenges and advantages.
Research Article
management
ali beiruti
Abstract
In Genaveh city, due to the absence of a desirable urban governance model, most programs have been top-down, leading to the undesirability of urban plans and schemes. The aim of this research is to enhance the indicators of good urban governance through the explanation of the Citizen's House model ...
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In Genaveh city, due to the absence of a desirable urban governance model, most programs have been top-down, leading to the undesirability of urban plans and schemes. The aim of this research is to enhance the indicators of good urban governance through the explanation of the Citizen's House model and approach in Genaveh and its extension to cities with a population of less than 100,000. Initially, the eight indicators of participation, efficiency and effectiveness, political stability, access to information, social justice, accountability, community-oriented, and legality were examined and evaluated using a combined analytical-quantitative and qualitative method. The research data was collected through library and field research methods. The target population was approximately 34,286 individuals, and the sample size was determined to be 384 using Cochran's formula. The indicators of good urban governance were analyzed using planning models and techniques such as TOPSIS and Fuzzy Vikor. The research findings and analytical test results indicate that the examined indicators are in an undesirable state and there is a need to improve their qualitative level in the neighborhoods of Genaveh city. The ranking results of the neighborhoods indicate variations in the level of governance across different areas. Finally, the Citizen's House approach was proposed in accordance with the conditions of Genaveh, with the aim of implementing it in Genaveh city first and then extending it to cities with a population of less than 100,000.
Research Article
management
Alireza Khedri
Abstract
The purpose of this research is to explain the proper urban governance model with emphasis on social capital (case study of Bushehr city). The statistical population includes a number of citizens of Bushehr city. From this number, according to Cochran's formula, 384 people were selected as a statistical ...
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The purpose of this research is to explain the proper urban governance model with emphasis on social capital (case study of Bushehr city). The statistical population includes a number of citizens of Bushehr city. From this number, according to Cochran's formula, 384 people were selected as a statistical sample. After interviewing expert professors and reviewing sources, the objective questionnaire of urban meritocracy was prepared. This questionnaire was considered as a research tool. After verifying the content validity of the items, several people were asked to answer the questionnaire and identify the incomprehensible phrases and words. The purpose of this work was to find out the possible problems of the test. After this test, the form of some items was changed, but no item was deleted. Research data was analyzed using spss24 software. Also, Amos25 software was used for confirmatory factor analysis. The method used to check the reliability of the questionnaire was Cronbach's alpha. According to the findings, it was found that the dimensions of the appropriate urban governance variables and social capital have a significant relationship. That is, the better the governance of Bushehr city according to the activists, the more the social capital of the activists in Bushehr city will be felt by the citizens.
Research Article
Civil Engineering
MohammadHossein Edalatkhah
Abstract
The aim of this research is to identify and rank the effects of Corona virus on the construction industry. To achieve this goal, library studies and analytical methods such as the fuzzy decision matrix and the use of expert questionnaires have been used. In this research, the most important effects of ...
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The aim of this research is to identify and rank the effects of Corona virus on the construction industry. To achieve this goal, library studies and analytical methods such as the fuzzy decision matrix and the use of expert questionnaires have been used. In this research, the most important effects of Corona virus have been examined according to criteria such as the probability of occurrence, the severity of the effect, and the probability of detection, and then they have been analyzed using the opinion of experts and analytical tools like Fuzzy Vikor Solver software. The results show that the most effective effects of Corona virus on the construction industry include things such as lack of housing, delays in projects and schedules, reduced economic development due to the suspension of construction activities, reduced demand for building structures, unemployment of daily income workers, financial losses to construction companies, and reduced employment. In the construction industry, increasing the financial risks of contractors, the possibility of non-compliance with organizational obligations, and creating psychological problems such as depression on unemployed workers and employees.
Research Article
civil engineering
hassan afshin; mohammadhossein ahmadian khameneh; mehrdad emami tabrizi; yasser alilou; Gholamreza Qudsi Sharif
Abstract
Shotcrete is extensively used as a concrete reinforcement in underground spaces, for Retrofitting, slope stability, and construction of shell structures. In this research, the performance of recycled micro steel fibers on the compressive and flexural behavior of shotcrete was investigated in two strength ...
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Shotcrete is extensively used as a concrete reinforcement in underground spaces, for Retrofitting, slope stability, and construction of shell structures. In this research, the performance of recycled micro steel fibers on the compressive and flexural behavior of shotcrete was investigated in two strength categories: normal and high performance. Based on the results, in normal shotcrete, due to the relatively low cement content and lower adhesion, the use of fibers resulted in a 15% decrease in compressive strength. However, due to the higher air pressure in normal dry shotcrete, better performance was achieved with the use of fibers. The use of admixtures in high-performance shotcrete mix designs, in addition to improving rheological properties, increased the average compressive strength by 50%. With the use of fibers, ductile behavior was observed in the plastic deformation range and the load-bearing capacity was continued by the fibers. A constant volume percentage of steel fibers (1%) indicated that the observed differences in energy absorption of the investigated mix designs are related to the concrete matrix. With the use of steel fibers, the minimum required energy absorption at a central displacement of 5 mm in circular panel specimens was met, resulting in an average increase of 58% and 19% in energy absorption in the wet and dry methods, respectively. However, the minimum required energy absorption at a central displacement of 40 mm was not met
Review Article
مهندسی عمران-سازه های هیدرولیکی
Omid Karbasi; Hassan Akbari
Abstract
Sea transportation is one of the main methods of moving goods between different countries in the world. In this regard, ports play an extremely important role and breakwaters are very important as the main structure of coastal protection. There are different types of breakwaters, including traditional ...
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Sea transportation is one of the main methods of moving goods between different countries in the world. In this regard, ports play an extremely important role and breakwaters are very important as the main structure of coastal protection. There are different types of breakwaters, including traditional rock mass breakwaters, platform breakwaters, vertical breakwaters, combined breakwaters, and special breakwaters. Due to cost reduction in construction, caisson breakwaters are used in deep waters. In the design and construction of these breakwaters, the reflection coefficient, wave overtopping and stability of the breakwater are important issues that make designers face many challenges. In order to improve the performance of caissons, various solutions have been proposed by researchers, among them Jarlan caissons in which perforated plates were placed in front of the caisson. In the following, after presenting the solution of creating holes on the front face of the caisson, many researchers have evaluated various variables to obtain the optimal plan in this regard. The collection of these researches confirm the optimal performance of caisson breakwaters with holes and some of them suggest new geometries on how to create holes. This optimized performance includes both better hydraulic response and, in some cases, reduced forces, which will improve stability. At the same time, other researches have been conducted on breakwaters without holes, and researchers have tried to improve their performance by changing the geometry of these caissons.
Review Article
مهندسی عمران-راه و ترابری
SeyedAref Hosseini; Reza Amin; Ali Khodaii
Abstract
This study meticulously reviews the impact of subway development on air pollution, focusing on China as a case study. Amidst rapid urbanization and escalating private vehicle usage, China's air pollution has soared, prompting significant investments in public transportation as a mitigation strategy. ...
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This study meticulously reviews the impact of subway development on air pollution, focusing on China as a case study. Amidst rapid urbanization and escalating private vehicle usage, China's air pollution has soared, prompting significant investments in public transportation as a mitigation strategy. This article examines how subway expansions correlate with changes in air quality across multiple Chinese cities, drawing from high-frequency data on air pollutants like PM10, PM2.5, NOx, SO2, and CO. A notable finding is that new subway openings generally lead to a decrease in PM10 and PM2.5 levels, with reductions averaging 17% across different cities. However, the study also identifies complexities in the relationship between subway development and air pollution reduction. While short-term impacts occasionally show increased pollutant levels, likely due to construction activities, long-term analysis reveals more consistent improvements. For example, after subway line inaugurations, PM10 levels initially rise by approximately 5% but subsequently decrease by around 9% over more extended periods. These dynamics underscore the effectiveness of subways in reducing air pollution, particularly in high-density urban areas, though the benefits may vary based on local conditions and the scale of the subway network. By integrating comprehensive spatial econometric analyses, this research not only highlights the direct benefits of subway infrastructure on environmental health but also enriches the policy dialogue concerning sustainable urban transport solutions in mega-urban settings.
Research Article
civil engineering
Parviz Fakhraei
Abstract
Abstract
The current research was conducted with the aim of rating the selection of construction materials in high-rise buildings using the fuzzy TOPSIS technique from the point of view of contractors. The results of data analysis were presented using fuzzy Delphi, fuzzy hierarchical analysis and fuzzy ...
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Abstract
The current research was conducted with the aim of rating the selection of construction materials in high-rise buildings using the fuzzy TOPSIS technique from the point of view of contractors. The results of data analysis were presented using fuzzy Delphi, fuzzy hierarchical analysis and fuzzy TOPSIS methods to identify and rank options based on indicators. The results of the fuzzy Delphi method showed that safety and health indicators and logistics should be removed. The results of the fuzzy hierarchical analysis method showed that the sustainability index is the most important and the legal and regulatory acceptance index is the least important index among the final indices obtained. According to the weights of the final indicators for the selection of building materials in high-rise buildings in the fuzzy hierarchical analysis method, the indicators were weighted in a fuzzy way for the fuzzy TOPSIS method. According to the results of TOPSIS Fazi method, polymer concrete, microcement, glass concrete, dry wall, sandwich panel, self-healing concrete, armalate, spider glass, carbon concrete, gas block, curtain wall and thermowall rank 1 to 12 respectively. They gave. It is hoped that in the not too distant future these materials will enter the construction materials market in high-rise buildings and help to reduce the consumption of natural resources, energy and water, as well as to create stronger and more environmentally friendly buildings.
Research Article
مدیریت ساخت و مدیریت پروژه
seyed ali asghar mousavi; alireza valipour
Abstract
Earned value management (EVM) is one of the most frequently applied methods in project management for the investigation of the performance and controlling of the temporal and cost progress of the project. Using its temporal and cost control indices, this method is capable of predicting the future status ...
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Earned value management (EVM) is one of the most frequently applied methods in project management for the investigation of the performance and controlling of the temporal and cost progress of the project. Using its temporal and cost control indices, this method is capable of predicting the future status of the project in terms of time and cost. But, this approach falls short of taking the risk analysis and project’s variability into account. The primary goal of the present study is the conceptual and subjective combining of risk management and EVM and investigation of the effect of risk occurrence on the project’s objectives using the EVM indices. To collect the information on the theoretical foundations and study literature and study background, use has been made herein of the Persian and Latin books, articles, dissertations and information databases and questionnaire and interview have been the methods of choice for gathering the information pertinent to the scales and indices. Moreover, in order to identify and prioritize the risks, the perspectives of the sophisticated experts and managers in civil activities have been inquired and ANP and Super Decision Software have been the instruments of interest for information analysis. After analyzing and evaluating and prioritizing the risk, the risk management process has been applied along with challenging the dimensions and factors influencing the project’s prospective performance to offer the risk coefficient that was subsequently combined with the current EVM indices for increasing the accuracy and precision of the project goals’ estimation. A civil reconstruction project (central building project of Shiraz’s municipality) in progress was evaluated for applying and comparing this method. Finally, it was found that the occurrence of risk has a significant impact on the project's objectives and changes its time and costs, additionally, given the risk factor, deviation from the time and cost of the project can considerably decrease.
Review Article
مهندسی عمران-سازه های هیدرولیکی
Omid Karbasi
Abstract
Numerical studies provide researchers with favorable facilities for research to investigate various cases. In conventional modeling, there are two approaches, Lagrangian and Eulerian. In the Eulerian approach with fixed meshing of the environment, the fluid flow enters the environment and then various ...
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Numerical studies provide researchers with favorable facilities for research to investigate various cases. In conventional modeling, there are two approaches, Lagrangian and Eulerian. In the Eulerian approach with fixed meshing of the environment, the fluid flow enters the environment and then various variables are investigated, but in the Lagrangian approach, the mesh is placed on the fluid particles and this causes the movement of the mesh along with the fluid. Smooth particle hydrodynamics (SPH) is a Lagrangian approach that has been favored by researchers in various engineering fields in recent years. This approach, which is based on kernel function interpolation, can consider compressible and incompressible fluid. The development of this method has accelerated more than before in view of removing the limitations and errors in its modeling in the past years. In this process, improved solvers and methods have been presented, including SPHysics and DualSPHysics. In the field of marine structures engineering, the investigation of the hydraulic response of breakwaters such as the overttoping and reflection coefficient and the force acting on breakwaters and pipelines is one of the application cases of smooth particle hydrodynamics. By improving the performance of this method, it is now possible to simulate porous environments, which creates a powerful tool in the hands of researchers. In this article, in order to better understand the limitations and possibilities of this method, its development in recent years has been examined and its applications in the fields related to marine structures have been reviewed in order to identify its weaknesses and strengths and its uses, other researches To be carried out in the continuation of research processes.
Research Article
civil engineering
farhad pirmohammadi alishah; mehdi Mohammadrezaei
Abstract
Nowadays, improving problematic soils is considered as one of the geotechnical engineering challenges. Since the problematic soils have a secondary origin that are the results of chemical weathering, they have a wide range of dispersive characteristics. One of these types of soils is clay that causes ...
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Nowadays, improving problematic soils is considered as one of the geotechnical engineering challenges. Since the problematic soils have a secondary origin that are the results of chemical weathering, they have a wide range of dispersive characteristics. One of these types of soils is clay that causes many problems in the engineering project. These problems are related to their specifications, such as week strength, settlement, and dispersivity problems. One of the treatment methods of the mentioned problems is chemical soil stabilization. One of the ways to improve soil quality is to use additives. Due to the widespread use of nanomaterials in different sciences, the impact of these materials as a novel additive can be investigated. In this study, the effect of nanosilica additive on bond strength of clay soils was investigated. In this study, we investigated the effect of nanosilica on unconfined compressive strength of clay soils in Jolfa region using in vitro and uniaxial experiments. Cohesive soil samples were tested by adding different percentages of nanosilica. The results indicate that nanosilica increased the uniaxial compressive strength of the clay soil. The results showed that the percentage of nanosilica additive for optimum compressive strength in clay soil was about 0.8%. Comparison of three series of clay compressive strengths in different percentages of nanosilica additives shows a minimum resistance of about 6 kg / cm2 and maximum resistance of about 9 kg / cm2.
Review Article
مهندسی عمران-راه و ترابری
Nemat Nawroozi; Reza Amin; Ali Khodaii
Abstract
One of the challenges in the construction of roads and airports that affects the transportation system is the freezing of the pavement surface, which can lead to accidents and cause financial and human losses. Historically, most countries around the world have used salt as a de-icing agent for pavements. ...
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One of the challenges in the construction of roads and airports that affects the transportation system is the freezing of the pavement surface, which can lead to accidents and cause financial and human losses. Historically, most countries around the world have used salt as a de-icing agent for pavements. While salt is effective for de-icing, it has destructive effects on both the pavement and the environment. Asphalt pavements, being a vital part of transportation infrastructure due to their importance in traffic safety and comfort, are significantly affected by the use of salt as a de-icing agent. This can lead to various types of damage, including increased degradation, cracking, and reduced lifespan of the pavements. These challenges have led to the search for new and innovative solutions for de-icing and preventing ice formation on pavements. This article examines the destructive effects of salt on asphalt pavements and evaluates and compares modern solutions for de-icing and preventing ice formation. These solutions include the use of organic materials, methods of using thermal energy for de-icing, which involves geothermal energy, non-geothermal energy, and electrical energy, as well as mechanical methods.
Research Article
مدیریت ساخت و مدیریت پروژه
seyed ali asghar mousavi; alireza vali pour
Abstract
One of the goals of knowledge of construction management is to identify the unforeseen factors and situations in the way of implementing projects in order to provide effective plans for dealing with potential risks and project risks. Risk assessment is one of the most important factors in risk management ...
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One of the goals of knowledge of construction management is to identify the unforeseen factors and situations in the way of implementing projects in order to provide effective plans for dealing with potential risks and project risks. Risk assessment is one of the most important factors in risk management and research indicates the need to use risk assessment to achieve success in construction projects. The aim of this study is to identify the types of risks in constructions projects based on the PMBOK, analysis, ranking and priority of risks using ANP method in order to improve the technical, qualitative and economic aspects of constructions projects. this research is in search of a suitable model that can use risk management and its methods in order to implement the economic and technical implementation of civil engineering projects. At first, 40 risks were identified in the context of 8 groups of risk factors through library studies and interviews, then by questionnaire and their analysis, were finally identified and ranked as the most important risks in constructions projects. Also, experts’ and experienced managers’ expertise in constructions activities was duly consulted to identify and prioritize the risks, and for the analysis of information, ANP and Super Decision software were used. Finally, it was found that the risk of delay in case of situations, adjustments and other costs to the contractor from the risk group of employers is the most important risk.
Research Article
Civil Engineering
Soleyman Jabbari Asli
Abstract
The cycle of freezing and thawing is one of the damage factors of concrete in cold regions. For this type of damage, the air temperature must change to the point of freezing, melting. The concrete must be in contact with water or humidity, and the porosity of the concrete must be inappropriate. The progression ...
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The cycle of freezing and thawing is one of the damage factors of concrete in cold regions. For this type of damage, the air temperature must change to the point of freezing, melting. The concrete must be in contact with water or humidity, and the porosity of the concrete must be inappropriate. The progression of damage depends on the number of cycles, temperature during solidification, porosity of concrete and environmental conditions of concrete. In this research, the effect of adding early-breaking cationic emulsion bitumen on the durability and other characteristics of structural concrete was investigated by performing water absorption tests, concrete resistance against freezing, melting, permeability, concrete resistance against chlorine ion penetration by electrical conductivity method. For this research, four mixing plans, one mixing as a control and three mixing with the addition of 2, 4 and 6 percent by weight of emulsion bitumen compared to the weight of cement were prepared. Slump tests, compressive strength, water absorption, permeability, durability of concrete against chloride ion penetration by electrical conduction method, surface resistance of concrete against chloride ion penetration and durability of concrete against freezing and thawing cycles were performed on the manufactured samples. The results showed that the addition of emulsion bitumen to structural concrete generally reduces the compressive strength and water absorption of concrete. Adding 6% bitumen reduces the permeability of concrete to the extent maximum. Regarding the durability of concrete against chloride ion penetration, the surface resistance of concrete against chloride ion penetration and the durability of concrete against freezing and thawing cycles do not have a positive effect, and in some cases, it causes a drop in these indices in concrete. Overall review, the results obtained from the conducted tests show that adding 4%, emulsion bitumen to concrete leads to better results.
Review Article
مهندسی عمران-راه و ترابری
Abdul Atiq Amiri; Reza Amin; Ali Khodaii
Abstract
Transportation of goods and passengers, especially by road and land, has been one of the most important needs of the human since ancient times until today. But some problems such as, environmental pollution that caused by transportation, increasing damages due to accidents, reducing energy resources, ...
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Transportation of goods and passengers, especially by road and land, has been one of the most important needs of the human since ancient times until today. But some problems such as, environmental pollution that caused by transportation, increasing damages due to accidents, reducing energy resources, traffic controlling and management problems, and increasing unauthorized speeds caused people to think of using new and effective solutions in this way, to solve the existing problems and improve the transportation process. So using from ITS, has been able to solve these problems largely. Intelligent Transportation System (ITS) is a new concept in this way that means the use of new technologies such as communications, controls, and electronic systems and increase the efficiency, security and dynamism of transportation. This article first introduce the ITS system and the effect of this system in road transportation, then the run of ITS system in Iran until the end of year 1400. The findings show a decrease in air pollution (25% in Sydney city according to statistics), a decrease in fuel consumption (10% in Paris city according to statistics), an increase in efficiency and traffic flow monitoring in the world's leading cities due to the use of ITS system, and also the use of some intelligent systems such as online traffic counter, weigh in motion, variable message displays and speed control and video surveillance cameras in the provinces of Iran by the end of 1400.
