Introduction
Air pollution is recognized as one of the most critical environmental and public health challenges of contemporary urban life. In megacities such as Tehran, rapid population growth, uncontrolled urban expansion, the widespread use of private vehicles, and the aging public transport fleet have intensified this crisis. Every day, more than seventeen million trips take place within the city, and over 2.4 million vehicles contribute substantially to air and noise pollution. Statistical reports indicate that the transport sector accounts for over eighty percent of mobile pollutant sources in Tehran, directly linked to increased respiratory diseases, premature deaths, and considerable social and economic costs. Both national and international studies emphasize that the transition toward clean and sustainable transportation is not only an environmental necessity but also a prerequisite for sustainable urban development. However, achieving this goal is impossible without broad and active citizen participation in planning, decision-making, and operating public transport systems. This research was conducted with the main objective of identifying and explaining the components influencing the establishment of clean transportation in Tehran, with particular emphasis on the pivotal role of public engagement, using Sherry Arnstein’s participation ladder as the theoretical framework.
Methodology
This study is applied in nature and employed a descriptive–survey design. The statistical population comprised 300 managers, officials, and experts working in Tehran’s municipal transport and traffic organizations, including the Tehran Municipality and the Tehran Metro Company. Based on Cochran’s formula, a sample of 166 respondents was selected. Data collection was conducted using a researcher-developed questionnaire, whose content validity was confirmed by experts, and reliability was assessed through Cronbach’s alpha (0.80), indicating acceptable internal consistency. For data analysis, SPSS (version 23) was used for preliminary statistical tests, while LISREL (version 8.5) supported structural equation modeling and confirmatory factor analysis. This methodological approach enabled a detailed examination of the relationships between citizen participation levels and the environmental, economic, and social indicators of clean transportation development.
Results and Discussion
The results demonstrated that the role of citizen participation varies across different dimensions. In the environmental dimension (R² = 0.77), reducing air pollutants through lower per capita CO₂ and greenhouse gas emissions (mean 4.45±0.22), mitigating noise pollution (4.18±0.45), and reducing water pollution (4.04±0.92) were identified as top priorities. Here, a combination of partial participation (awareness, consultation, consensus) and full participation (partnership, empowerment, control) yielded the most effective outcomes. In the economic dimension (R² = 0.71), indicators such as reducing daily commuting time, improving accessibility to employment opportunities, and lowering travel costs were better explained through passive and partial participation, as major economic interventions often require large-scale governmental and private sector investment beyond the immediate control of citizens. In the social dimension (R² = 0.79), factors such as enhancing transport safety, improving accessibility for pedestrians and people with disabilities, and facilitating access to cultural and historical sites were most significant. In this area, once again, a balanced combination of partial and full participation emerged as the optimal approach. Overall, the findings indicate that citizen participation is not a single-layer phenomenon but a dynamic, multi-level process, requiring differentiated strategies tailored to each dimension.
Conclusion
The analysis of the findings indicates that the development of clean transportation in Tehran is not achievable without recognizing and enhancing the role of citizens. In the environmental and social dimensions, raising public awareness, strengthening the sense of responsibility, and creating conditions for genuine citizen participation through partnership and empowerment are the main drivers of success in reducing pollution and improving urban quality of life. In contrast, the realization of economic indicators in clean transportation relies less on direct citizen involvement and more on large-scale investments and structural decisions made by government and private sector actors. Overall, the study concludes that a balanced and integrated strategy, which simultaneously addresses environmental, social, and economic dimensions, is the key to achieving clean and sustainable urban transportation in Tehran. Such an approach requires the promotion of public awareness and education, the cultivation of social trust, and the institutionalization of participatory mechanisms that enable citizens to play an active role in planning and monitoring. Furthermore, it is recommended that urban policymakers prioritize the modernization of the public transport fleet with electric and low-emission vehicles, expand pedestrian and cycling infrastructure with an emphasis on safety, and adopt intelligent traffic management systems to mitigate peak-hour congestion. Designing financial and legal incentives to attract private sector investment, strengthening the role of non-governmental and community-based organizations, and integrating land-use planning with transport policies are also crucial measures. Implementing such a multidimensional and participatory approach can pave the way for significant reductions in air pollution, improvements in safety and social equity, and progress toward a healthier and more sustainable urban future for Tehran.