In recent decade, regard to growing trend of Fuel conception in transportation section and the resulted economic losses resulted changing policy of consumption Fuel to compact natural gas, has been regarded in work command of government man and making essential infrastructures in this field is so essential. The most important essential infrastructure is establishing CNG Fuel station. The policy cause that the CNG Fuel places will be one of the most important city service centers in city centers. Shiraz city as the sixth metropolis in our country, have some problems in the field of CNG Fuel places, lack of stations, unsuitable distribution of stations, unsuitable locating stations etc. therefore we should use the method which by assuming the all factors, we can define the best stations for CNG Fuel places in this city. The research method in this study is description analytical which its essential information have been acquired via field observation, interviewing and studying the designed drawings related to Shiraz city and the 1/2000 map of this city. In this research, to analyse the current situation in CNG Fuel, Shiraz city has been chosen for case study, then by using the GIS integral and network analyzing, the existing condition of the CNG Fuel stations in shiraz have been examined and after recognizing unsuitable distribution and the shortage of CNG Fuel stations, by assisting the AHP model and indices overlapping in GIS software, the city lands have been valued according to the priority from most suitable to most unsuitable in 7 groups to make new Fuel stations for CNG.

The use of compressed natural gas as a clean fuel in the transportation sector is growing around the world. Moreover, regarding the growth of vehicle use in Iran and due to the higher fixed investment requirements, finding the suitable locations is an important issue. The flow refueling location model is one of the models that have proposed recently to find refueling locations. In this study, finding the best CNG locations for two major suburban routes of Tehran consist of Tehran- Firoozkooh and Tehran- Semnan has been studied using the flow refueling location model. The results showed that the selected place to build a CNG station in Tehran- Firoozkooh route is at the end of Tehran-Damavand road before the Boomehen fire station with geographical coordinates (35.74,51.85) and the selected place to build a CNG station inTehran-Semnan route is in the Eyvankeh petrol station in the beltway Eyvankeh with geographic coordinates (35.35,52.05)

Energy is one of the main pillars of the economic cycle. The environmental pollution caused by the consumption of gasoline and diesel fuel, the problems and limitations of supplying and supplying fuel within the country, moving towards self-sufficiency in the supply of gasoline and diesel fuel, reducing government spending against income and also allocating macro subsidies to keep their prices low for Increasing satisfaction and public welfare are among the government's concerns. In recent years, the use of alternative fuels, in particular CNG, has attracted the attention of the government in the transportation sector. The purpose of this research is mapping the mapping to improve the use of CNG fuel in the transportation sector using the Strategic Option Development and Analysis. Experts and stakeholders selected based on the job title, work experience, degree of education from professional experts and executives in the management of the CNG project, managers, experts and specialists of the automotive dual car manufacturing company, the companies producing parts of the gas system and the conversion of workshops of automobiles Diesel fuel and CNG equipment manufacturers, CNG locators, taxi organization (consumer representative) and postgraduate students (graduate and postgraduate degrees). The research data are provided through interviews with this experts and stakeholders, and finalized maps using the Explorer Decision software were designed and analyzed. D As a result, 18 effective factors were identified. Based on the results, the desire to use CNG fuel instead of gasoline, CNG sustainable development and the development of a CNG vision document are key issues for improving the use of CNG fuel in the transportation sector. Finally, according to the outcomes of the maps and expert opinions, effective and strategic alternatives, such as the elaboration of a long-term plan for the country's fuel basket, the release or determination of the appropriate rate for the price of all fuels, the provision of targeted facilities for the supply of CNG fuel, continuous advertising And influential, and strategies for achieving these goals were proposed for policy makers.

One of the main goals of all governments and organizations controlling urban management is to balance spatial distribution of resources and services in cities. Equal distribution of services needs pinpointing the locations of services and facilities in a way that all citizens have equal access to them. Providing CNG fueling stations in urban areas (with the emphasis on their accessibility) is one of the major urban services that has attracted a great deal of attention. Since Ardabil city is also the center of Ardabil province, it has experienced the increase in population density and growth that has led to insufficiency (due to the imbalanced distribution of services) in providing urban services such as CNG fueling stations in different areas. This study aimed to evaluate present condition of CNG fueling stations, to locate new stations optimally and to increase citizens’ access to these stations. Due to its nature and objectives, research method is descriptive-analytical. Hence in this study CNG fueling stations were pinpointed using data from descriptive analysis and field observations; moreover, criteria (12 criteria) for locating these stations in Ardabil city were assessed through AHP model and the urban areas with no or limited access to these stations were identified. The results of zoning in Ardabil city to locate CNG fueling stations indicated that the most unsuitable and suitable zones contained 22.5 % and 15.8 % of the areas in Ardabil city, respectively. Moreover, the obtained results indicated that through establishing 6 new CNG stations we can optimize providing services to the citizens. In this regard the suggested CNG stations were studied through TOPSIS model and utilizing 8 effective criteria for their optimal spatial distribution, then they prioritized. The results indicated that the existing CNG fueling station in Ardabil city are not in line with urbanization standards and besides providing undesirable services they don’t match with land use around them. This is in turn defines the need to reconsider the position of CNG fueling stations and establishing new stations in Ardabil city

The choose of the most appropriate place to build an economic enterprise in each region is very important and it requires to know the effective indicators in different fields. The importance of this issue is especially doubled with in areas that are facing limited resources and facilities and it increased with the improving demand due to population growth. Industrial goods, including cars and their fuel, are of this type. there is much more interest in special fuels such as CNG. For this purpose, the present research was conducted with the aim of investigating the economic factors affecting CNG fuel stations in Chaharmahal and Bakhtiari provinces in the year 1400. This research was done by questionnaire method and AHP and with SPSS and Expert Choice software. Effective indicators in this regard are the economic index of the location - production (communication network), land use, distance from fire stations, distance from gasoline fuel stations, distance from diesel fuel stations, CNG fuel stations, slope, distance from high-traffic streets, distance Among the fire-prone places, Chaharmahal and Bakhtiari provinces are one of the most effective factors in locating the CNG fuel stations, and they have a higher priority respectively.

In the present research, challenges of using CNG as an alternative in fuel basket of the transportation sector are investigated considering the results of a survey. 1601 natural gas vehicle drivers, 41 CNG stations, 28 conversion workshop and 44 licensed repair and service centers in Tehran participated in the survey. The study released that busy stations, out of service equipments at the stations, high cost of CNG station construction and maintenance, relatively low capacity, technical problems of the equipments and unsuitable dispersion have been the most significant challenges. Long queues for vehicle system conversion and unauthorized conversions have been the major issues with the conversion workshops. Unsuitable access to gas system spare parts and their low quality have been the serious problems at licensed repair and services centers. In summary, the above-mentioned cases are known as the main challenges within CNG infrastructures. For CNG-using vehicles, the short distance vehicle can travel with a full CNG tank and low acceleration rate have been found as the most considerable challenges. Over-focus on using CNG as alternative fuel in transportation sector, only because it is an easy-access and cheap natural source (in comparison to the other ordinary fuels in Iran) cannot present a logic policy for transportation energy supply in the future. Therefore, developing infrastructure to use biodiesel, hybrid, hydrogen and electricity is suggested to alleviate future fuel challenges.

Hybrid cars have become increasingly popular among drivers. Affordable CNG, similar fuel efficiency (substitute product) and gasoline rationing have caused use of gas to be considered as an alternative fuel. Thus, providing CNG fuel stations to offer more services to the gas users has become one of the priorities in public and private sector. Small number of available stations, long queues which gas customers face at the CNG stations and increase in the number of hybrid vehicles necessitates establishment of new stations. This research work is to develop a model based on a heuristic solution to find suitable locations for constructing CNG stations. The main purpose f the model is to minimize the refueling trip distance. Modeling has been done for the case of Isfahan and will be finally implemented in this city.

Transportation sector is the major consumer of oil products. Since consumption of gasoline has increased during the recent years, pollution of air and warming up of the earth as result of the production of green house gases, has increased. Natural gas, due to its environment friendliness as one of its characteristics, can become the dominant fuel in the transportation sector. In this study, we have evaluated the amount of Green House Gases produced from transportation sector using Clean Development Mechanism formuala. Then external and social costs from produced Green House Gases, the economies of the owner`s and governmental view and the present capacity of CNG stations to replace the CNG for other conventional fuels in zanjan city, were studied according to the variety of sceneries (increasing amount of bi-fule vehicles 25%, 50%, 75%, 90%, respectedly). The results show that the most amount of Greenhouse Gasses (GHGs) belong to the vehicles with conventional petrol engines which exceeds 2.08×1011 CO2 tonnage in a year imposing external and social costs which amount to $2.9×1012 and $1.6 ×1012, respectively, in just one single year. The least amount of (GHGs) belong to the CNG fueled vehicles with 3.4×109 CO2 tonnage in a year imposing external and social costs that would be $1×1010 and 1.4 ×1011, respectively, in just one single year. This study implies that the cost is mounting up, in the owner`s and governmental view. The present capacity of CNG stations to replace the CNG for other conventional fuels is just suited to the existing conditions in this city and the number of bi-fuel vehicles, but in other sceneries which requires that the city must be provided with other stations, should be disused in an independent study.

Energy is one of the most important issues of the world today. Given the limited energy resources and the increase in the prices of energy carriers in Iran, identification of methods and solutions for supplying resources and energy consumption in the energy and energy industries such as transportation is very necessary. In this regard, due to the rich natural resources of the country and the government's investment in this sector, the importance and role of compressed natural gas (CNG) as one of the best gasoline alternatives in cars in the past years has been identified. On the other hand, due to the role of various factors in economics, politics and society in the performance of this industry, policy and planning are associated with particular complexities. Hence, in this paper, a systematic approach is proposed to provide appropriate solutions for the development of optimal use of compressed natural gas (CNG) instead of petrol as a fuel for the road transport sector based on the important impacts of this industry and their effectiveness on the basis of the dynamic system Designed and decomposed. An approach that involves and interacts with all the factors involved, as well as adopting a glimpse into the compressed natural gas (CNG) industries in the transportation sector, provides appropriate solutions for the development of an appropriate economic system. Accurate and timely information, creates a long-term program for the fuel basket, Suitable fuel prices, the proportions of the growth of Duncan cars with compressed natural gas (CNG) supply sites, are known as effective development variables in use of compressed natural gas (CNG) instead of gas is known in Iran's road transport system. Finally, make the necessary and effective suggestions based on the systematic analysis to create a growing trend to government officials and policy makers.