Transportation Planning to Reduce Private Car Usage with an Emphasis on Psychological Motivations (Case Study: Regions 1 and 3 of Isfahan Metropolis)

Introduction : Urban transportation has been shaped since World War II by focusing on private cars. Today, in most cities and countries, this focus is still evident in common planning methods. This is because using a car has many benefits for individuals, households, and society as a whole. In addition to providing easier access to different places, using a private car brings other benefits such as flexible scheduling, relatively shorter travel time, convenience, and lower incidental costs for individuals. However, along with the advantages of using a private car, there are also several disadvantages that have created significant risks to urban life. Among these are the increase in greenhouse gas emissions, traffic congestion in urban areas, significant waste of citizens' time in daily traffic, and the intensification of air pollution. In the Isfahan metropolis, along with various challenges in various areas related to the urban system, transportation issues have become one of the most serious challenges. It is worth noting that among all the regions of the Isfahan metropolitan, regions 1 and 3 can be considered as the most important and key regions of the city. Because many important urban activities are scattered in these regions, and from a systemic perspective, efforts to solve traffic problems in these regions, if effective and operational, can have positive and beneficial results not only for improving the situation in these areas but also for the entire transportation system of the Isfahan metropolis.
Methodology: The present study is applied research with a descriptive-analytical approach. Data collection was carried out by two methods: library and field. In the field study, the necessary information was obtained by visiting regions 1 and 3 of Isfahan and distributing questionnaires among 677 citizens. SPSS software was used for descriptive and inferential data analysis, and System Dynamics and Vensim software were used to integrate the results. 
Results: The results indicate that factors such as cost, comfort, convenience, control, safety, power, self-confidence, and the competence of car owners, along with their related indicators, have had the greatest impact the use of private cars.
Discussion: The use of private cars in Isfahan is one of the major challenges in the areas of transportation and urban planning. This is not only an environmental and economic concern, but also has profound impacts on the daily lives of citizens. Examining this phenomenon from different perspectives – including traffic congestion, air pollution, urban space occupation, reduced pedestrian safety, economic burden, and impacts on the overall quality of life – can help to provide a more comprehensive understanding of the challenges and potential solutions to address them. The first and most obvious problem caused by the use of private cars in Isfahan is traffic congestion. Heavy traffic during peak hours reduces vehicle speeds, increases travel time, and increases driver stress. Furthermore, increased congestion negatively impacts the efficiency of the public transport network, causing increased delays and reduced system reliability. This ultimately reduces citizen satisfaction and reduces their willingness to use public transport services. The second major issue related to the use of private cars is air pollution. Private cars are among the main sources of emissions of gases such as carbon dioxide, nitrogen oxides and particulate matter, all of which contribute significantly to the reduction of air quality. This pollution has direct adverse effects on the public health and general well-being of citizens. In addition, air pollution exacerbates respiratory and cardiovascular diseases and hinders the achievement of public health goals. The third issue is the occupation of urban space by private vehicles. Irregular and unauthorized parking practices lead to encroachment on public spaces and reduced access to public facilities and green areas. As a result, these conditions reduce urban liveability and increase residents’ sense of insecurity in public spaces. The fourth issue concerns the reduction in safety for pedestrians and cyclists. Heavy traffic and reduced driver attention increase the likelihood of accidents and injuries among vulnerable road users. Finally, the use of private cars imposes a significant financial burden on citizens. These costs include fuel consumption, vehicle maintenance, insurance premiums, and parking fees, all of which can pose serious challenges for many households and lead to economic and financial strain.
Conclusion: The main factor identified in reduction of private car use in regions 3 and 1 is instrumental value, as the lack of adequate public transport infrastructure has led citizens to prioritize convenience and control. However, the findings indicate that positive attitudes toward sustainable transportation and social norms can moderate these motivations. In particular, citizens who are aware of the environmental benefits are more likely to reduce car use.