Journal of Transportation Research

Journal of Transportation Research

Optimal policies for reducing carbon dioxide emissions in Iran's light vehicle fleet

Document Type : Original Article

Authors
سحر رفیعی 1
Zeinolabedein Sadeghi 2
Kourosh Qaderi 3
1 M.Sc. Grad., Faculty of Management and Economics, Shahid Bahonar University of Kerman, Iran.
2 Associate Professor, Department of Economics, Faculty of Management and Economics, Shahid Bahonar University of Kerman, Kerman, Iran.
3 Associate Professor, Department of Water Engineering, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran.
10.22034/tri.2026.553775.3391
Abstract
The light-duty transportation sector in Iran, as one of the main sources of greenhouse gas emissions, plays a significant role in increasing carbon dioxide (CO₂) levels and intensifying climate change. The sector’s heavy dependence on fossil fuels, outdated engine technologies, and the high carbon intensity of the power grid have led to a rising trend in emissions over recent decades.

The aim of this study is to analyze optimal decarbonization pathways for Iran’s light-duty vehicle fleet through 2050. To achieve this goal, time series modeling (Auto-ARIMA) and policy scenario simulations were conducted using the GAMS environment, in which five scenarios—ranging from “business as usual” to “optimistic policies”—were designed and examined. The results indicate that if the current trend continues, the number of light vehicles in the country will exceed 50 million units by 2050, and CO₂ emissions will more than double. In contrast, under the optimistic scenario—which assumes an increase in the share of electric and hybrid vehicles to 20%, a 30% improvement in the fuel efficiency of combustion vehicles, and a reduction in the carbon intensity of the power grid from 0.60 to 0.40 kg CO₂ per kWh—total fleet emissions would decline by more than 30%. The findings emphasize that achieving decarbonization targets requires comprehensive policies, including the development of clean technologies, reform of the power generation structure, fleet modernization, and the design of economic incentive mechanisms for users. These results can serve as a basis for national policymaking toward achieving sustainable and low-carbon transportation in Iran.
Keywords
Decarbonization
electric vehicles
electricity grid
policy scenarios
light transportation
Subjects
-برخوردار، عادل، سادات و ورهرامی، ویدا (۱۴۰۳). ارزیابی تاثیر جایگزینی سوخت در بخش حمل‌و‌نقل بر انتشار گازهای گلخانه‌ای. نشریه انرژی‌های تجدیدپذیر و نو، ۱۱(۱)، 99-90.
-حسینی، میثم (۱۳۹۹). مدل و الگوریتم حل مسئله مکان‌یابی جایگاه‌های سوخت برای خودروهای دوگانه‌سوز به‌منظور مینیمم‌کردن انتشار گازهای گلخانه‌ای. پژوهشنامه حمل‌و‌نقل، ۱۷(۳)، ۱۲۱-۱۴۲.
-مرکز آمار ایران. (1402). نتایج سرشماری عمومی و گزارش آمار ناوگان حمل‌ونقل جاده‌ای ایران.
-ناظمان، حمید و حقدوست، احسان (۱۳۹۱). بررسی امکان صرفه‌جویی در مصرف سوخت و کاهش آلودگی هوا با استفاده از خودروهای برقی-بنزینی (الکتروهیبرید). پژوهشنامه اقتصاد انرژی ایران، ۱(۴)، 196-169.
-مؤسسه مطالعات بین‌المللی انرژی (1398). چشم‌انداز انرژی ایران در افق 2040. تهران.
-وزارت نفت (1400). گزارش سالانه شرکت ملی پخش فرآورده‌های نفتی ایران. تهران: معاونت برنامه‌ریزی و نظارت.
 -وزارت نیرو. (۱۴۰۱). آمار ترازنامه انرژی سال ۱۴۰۱.
-BP. (2024). Statistical review of world energy 2024. BP p.l.c.
-Changchun, L., Zhen, Y., & Xia, H. (2022). Transportation decarbonization pathways in developing economies: Policy and technology synergies. Energy Policy, 164, 112–125. https://doi.org/10.1016/j.enpol.2022.112125
-Du, H., Chen, Z., Zhang, Z., & Southworth, F. (2020). The rebound effect on energy efficiency improvements in China’s transportation sector: A CGE analysis. Journal of Management Science and Engineering, 5(4), 249–263. doi.org/10.1016/j.jmse.2020.05.004
-Emodi, N. V., Okereke, C., Abam, F. I., Diemuodeke, O. E., Owebor, K., & Nnamani, U. A. (2022). Transport sector decarbonisation in the Global South: A systematic literature review. Energy Strategy Reviews, 43, 100925. doi.org/10.1016/j.esr.2022.100925
-European Commission. (2021). Proposal for a regulation of the European Parliament and of the Council amending Regulation (EU) 2019/631 as regards strengthening the CO2 emission performance standards for new passenger cars and new light commercial vehicles in line with the Union’s increased climate ambition (COM(2021) 556 final).
-Ferguson, M. M., Sharmin, A., Camur, M. C., & Li, X. (2025). A review on intermodal transportation and decarbonization: An operations research perspective. arXiv preprint arXiv:2503.12322. doi.org/10.48550/arXiv.2503.12322
-Ghisolfi, V., Tavasszy, L. A., Correia, G. H. d. A., Chaves, G. d. L. D., & Ribeiro, G. M. (2022). Freight transport decarbonization: A systematic literature review of system dynamics models. Sustainability, 14(6), 3625. doi.org/10.3390/su14063625
Glyniadakis, S., & Balestieri, J. A. P. (2023). Brazilian light vehicle fleet decarbonization scenarios for 2050. Energy Policy, 181, 113682. doi.org/10.1016/j.enpol.2023.113682
-Huo, H., Cai, H., Zhang, Q., Liu, F., & He, K. (2015). Life-cycle assessment of greenhouse gas and air emissions of electric vehicles: A comparison between China and theUS. AtmosphericEnvironment, 108,107–116.
doi.org/10.1016/j.atmosenv.2015.02.041
-IEA. (2021). World Energy Outlook 2021. International Energy Agency.
-IEA. (2022). Global EV Outlook 2022. International Energy Agency.
-Intergovernmental Panel on Climate Change. (2006). 2006 IPCC guidelines for national greenhouse gas inventories: Vol. 2: Energy. Institute for Global Environmental Strategies.
-IPCC. (2022). Climate change 2022: Mitigation of climate change. Cambridge University Press.
 -Patil, G., Pode, G., Diouf, B., & Pode, R. (2024). Sustainable decarbonization of road transport: Policies, current status, and challenges of electric vehicles. Sustainability, 16(18), 8058. doi.org/10.3390/su16188058
-Requia, W. J., Mohamed, M., Higgins, C. D., Arain, A., & Ferguson, M. (2018). How clean are electric vehicles? Evidence-based review of the effects of electric mobility on air pollutants, Greenhouse Gas Emissions and Human Health. Atmospheric Environment, 185, 64–77. doi.org/10.1016/j.atmosenv.2018.04.041
-Solaymani, S., & Botero, J. (2025). Reducing carbon emissions from transport sector: Experience and policy design considerations. Sustainability, 17(9), 3762.
­doi.org/10.3390/su17093762
-United Nations Environment Programme. (2019). Emissions gap report 2019.
-World Bank. (2023, June 1). Electric mobility & power systems. Open Knowledge Repository.
-Zeyen, E., Kalweit, S., Victoria, M., & Brown, T. (2025). Shifting burdens: How delayed decarbonisation of road transport affects other sectoral emission reductions. Environmental Research Letters, 20(4), 044044. doi.org/10.1088/1748-9326/abf123
-Zheng, Y., He, X., Wang, H., & Wang, M. (2020). Well-to-wheels greenhouse gas and air pollutant emissions from battery electric vehicles in China. Mitigation and Adaptation Strategies for Global Change, 25(5), 779–798. doi.org/10.1007/s11027-019-09890-5
Journal of Transportation Research
Volume 23, Issue 3
Summer 2026
Pages 471-482