Sustainability 2022, 14, 14462. https://doi.org/10.3390/su142114462 www.mdpi.com/journal/sustainability Article Comparing Inequality in Future Urban Transport Modes by Doughnut Economy Concept Ali Alamdar Moghaddam 1 , Hamid Mirzahossein 1, * and Robert Guzik 2 1 Faculty of Technical and Engineering, Imam Khomeini International University, Qazvin 34148-96818, Iran 2 Institute of Geography and Spatial Management, Jagiellonian University, 31-007 Kraków, Poland * Correspondence: mirzahossein@eng.ikiu.ac.ir Abstract: Inequality is a problem facing the world community, especially in developing countries, that affects urban transport and vice versa. Which possible urban transportation mode will cause the least inequality? This is a vital question. The development of Autonomous vehicles (AV) has made Shared Autonomous Vehicles (SAV) one of the future transport modes. Active and public transport are also mentioned as applicable future modes, based on the literature. This paper aims to compare inequality in active transportation, public transport and SAV as the most important al- ternatives to private cars in the future. In this regard, we use doughnut economic concepts as the framework for our comparison. First, the inequality concept is expanded and then literature demonstrates the future desirability of modes. We show why doughnut economics could be a beneficial alternative for comparing that resulted in the superiority of active and public transport over SAV in terms of future inequality. Keywords: inequality; active transport; public transport; shared autonomous vehicle; doughnut economy 1. Introduction Sustainable development is a still growing concept approximately five decades since its introduction [1]. It shapes policy and strategies at all levels of governance from the United Nations, supranational bodies such as the European Union, countries, regions and localities. Researchers have tried to identify different dimensions of sustainable de- velopment according to their field [2]. However, despite global development, many goals set for sustainable development have not been achieved, such as equality. Inequality is still one of the most significant challenges, despite globalization and national develop- ment. The rapid development of cities is one of the essential issues of the 21st century. The Department of Economic and Social Affairs of the United Nations predictions show the importance of this problem. According to the latest forecasts, by 2030, the proportion of urban dwellers in the world’s total population will reach 60%. This ratio will reach more than 68% in 2050. In 2018, the urban population ratios in Africa and Asia were 40% and 50%, respectively, which will reach 59% and 66% in the middle of the current century [3]. Thus, the growth of urbanization is more overriding in developing countries. Immigra- tion and birth rates are two principal factors in increasing the population of cities. In these countries, cities provide much better opportunities for living [4]. So urban birth rate and internal migration rate (from rural to urban) in developing countries are significantly higher than in developed countries [5,6]. Urbanization growth is considered a factor in economic growth, poverty reduction and human development [3], but developing countries face various problems in their urban development process. The rapid growth of the urban population in developing countries has led to a significant part of the urban population not benefiting from basic living facilities. For example, slums formed in dif- Citation: Moghaddam, A.A.; Mirzahossein, H.; Guzik, R. Comparing Inequality in Future Urban Transport Modes by Doughnut Economy Concept. Sustainability 2022, 14, 14462. https://doi.org/10.3390/su142114462 Academic Editors: Muhammad Zaly Shah, Eng. Muhammad Isran Ramli and Antonio Nelson Rodrigues da Silva Received: 25 September 2022 Accepted: 30 October 2022 Published: 3 November 2022 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and insti- tutional affiliations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/license s/by/4.0/).