مطالعه آثار و نتایج اقتصادی و زیست‌محیطی ناشی از اضافه شدن یک خط آهن جدید به شبکه حمل‌ونقل ریلی

The indicators used to determine transportation policies and guide investments in the infrastructure sector seem to be different for different regions. However, two major goals are jointly important: first, the need to improve the efficiency of the transportation network in order to reduce pollution caused by freight and passenger transportation (Abraham et al., 2012) and second, increasing the share of railways as a clean means of transportation in the transportation matrix; Therefore, the need to use a model that fulfills both of these goals seems important because among the transportation methods, rail modes have less energy consumption and pollution compared to roads. Also, the capacity to carry more cargo and passengers in each trip compared to the road mode, which depends on the width of highways and traffic, is another advantage of rail transportation. Roads account for approximately 61.1% of all transported cargo, while in some developed countries with relatively similar geographical dimensions, this amount is less than 30% (CNT, 2018). In a case study that examines the need to focus on domestic transportation for the export and transfer of agricultural products such as: wheat, corn, soybeans, etc., it is stated that approximately 50% of it is by the road sector, 40% by the railway sector. and 10% is transported by waterways (Brazil Rail Transport, 2019). In the country's public transport statistics, it is stated that Brazil has more than 1.7 million kilometers of roads, while there are only 30 thousand kilometers of active rail network and 20 thousand kilometers of waterways for the transit of goods and cargo (same source, 2019). ). This statistic also shows that the total public investments made in road, rail, port, air and water infrastructure between 2010 and 2017; It has decreased by about 37% (Arvis et al., 2018). Similarly, in the same period of time, the amount of transportation of grain, soybeans and corn produced in the mentioned country has increased by 61% (Ekisi et al., 2016). The area under cultivation to support additional productions with the expansion of the agricultural territory and becoming one of the export poles shows the necessity of dynamic transportation performance in this country and this is the situation that the development of transportation has not been done much and on the other hand the consumption of fossil fuels and emissions Greenhouse gases (GHG) have reached a much higher level. The transportation sector consumes about 35% of fossil fuels and more than 48% of greenhouse gas emissions in this country are due to the activity of this sector (Folin et al., 2018). The low efficiency of transportation in this country has caused an increase in losses and its costs will have a negative effect on the competitiveness of parts of the economy. The unfavorable performance of the transportation system, especially in the grain export sector, has highlighted the need to invest in rail transportation infrastructure. Global trends for investment with regard to green transportation development policies, in order to create transportation dynamism as well as logistics for economic development and continuous social welfare of citizens, make it necessary (Akiaro et al., 2014). However, there are increasing concerns about environmental protection and sustainable development in terms of diverse and scattered external effects of transportation systems, and they have constantly put pressure on the officials who develop transportation and logistics plans and policies to the extent that environmental and social considerations are included in the plans. comprehensive based on economic analysis (Chang et al., 2008). This goal to minimize the environmental impact of logistics is known as "green logistics" (Macharis, 2014). damages and disadvantages caused by air pollution and climate changes; It has forced countries to adopt a common agenda, which is summarized in the category of reducing fossil fuel consumption (Davarzni, 2012). The 1997 Kyoto Protocol and the 2015 Paris Agreement are examples of international agreements to encourage ambitious efforts to combat climate change and adapt to environmental impacts (UNFCCC, 2018). National measures to deal with climate change, especially by investing in energy alternatives and more efficient current methods for its management, are among the issues that have been addressed by policymakers in the transportation sector. The urgent need for decarbonization in the transportation sector, especially in the road transportation sector, has significantly increased the need to reduce the negative side effects of the environment in this sector (Ducrot et al., 2016). The transportation sector was the source of approximately 23% of the world's total energy-related CO2 emissions (equivalent to 6.7 gigatons of CO2) in 2010 alone (ibid., 2016). This is despite the implementation of policies designed to reduce fuel consumption and replace high-consumption vehicles with more efficient types of energy in the current transportation fleet, the emission of greenhouse gases from the potential transportation sector is almost twice the level obtained for it in 2010. About 12 gigatons of CO2 by 2050 (Farias, 2018). However, without the implementation of sustainable policies related to the reduction of greenhouse gas and CO2 emissions, it can be reduced in the passenger and cargo transportation sector by avoiding unnecessary trips as much as possible. Changing consumption patterns towards the use of low-carbon transportation systems and reducing the level of intensity of energy consumption in units (passenger-kilometer or ton-kilometer) and reducing the intensity of produced carbon (CO2eq/MJ) through the use of alternative fuels, including government measures
Policies related to transportation development and investment for transit infrastructure are different in different countries. However, the measures taken to improve the performance of the transportation industry and simultaneously reduce the emission of greenhouse gases and CO2 have become more important. In Iran, the lack of necessary platforms and infrastructures has caused the low productivity of transportation and the consequent increase in costs. On the other hand, air pollution caused by CO2 emissions is one of the causes of the inefficiency of the transportation sector, as far as the government's upstream documents provide strategies for attracting capital and the participation of public and private sectors in the development of the rail transportation industry. In this research, using a two-stage model, the economic and environmental impacts expected from the point of view of a new rail line have been evaluated, and the results have suggested suggestions for increasing the capacity of rail transport as follows: First) a balanced and network model for Simulating freight transport flows between grain production areas and evaluating the economic benefits of developing a rail network by making relevant measurements from the perspective of reducing transportation costs as well as reducing CO2 emissions that result from the construction of a new railway b) Conducting cost-benefit analyzes for value ranking Investing in railways according to its economic and environmental contribution.
Research findings show that the implementation and operation of a new rail line can reduce the total cost of transportation by 17%. Also, a 20% reduction in total CO2 emissions for grain planting and harvesting areas is one of the other economic and environmental achievements of the study, which seems attractive and motivating for financing and taking advantage of the potentials of the private and public sectors.