Shared cars have emerged as a novel model based on the sharing economy, aimed at mitigating urban challenges, particularly traffic congestion and air pollution. This study seeks to identify and prioritize the advantages and disadvantages of developing shared-car systems across five dimensions: economic, social, environmental, infrastructural, and managerial. Methodologically, the study employs a descriptive-analytical approach. Data were collected through a systematic review of the literature and the participation of 50 experts. The SWARA and MARCOS methods were employed to determine the weights and rank the criteria. The findings indicate that, despite limitations such as security concerns, cultural barriers, and the absence of a comprehensive legal framework, shared-car systems have considerable potential to improve urban transportation, reduce pollution, and lower transportation costs. According to the MARCOS results, the economic dimension received the highest score (0.715), followed by the environmental (0.685), social (0.666), infrastructural (0.629), and managerial (0.614) dimensions. The first-place ranking of the economic dimension highlights the central role of shared-car systems in reducing transportation costs and optimizing resource allocation, while the second-place ranking of the environmental dimension underscores the close relationship between environmental sustainability and economic efficiency in urban planning. Overall, policymaking should focus on leveraging the economic, environmental, and social benefits of shared-car systems, while infrastructural and managerial barriers should be addressed progressively and in line with the growth in demand. The development of smart infrastructure and the establishment of a clear legal and regulatory framework are essential to realizing the potential of this emerging transportation model.