Citation: Farzin, I.; Abbasi, M.; Macioszek, E.; Mamdoohi, A.R.; Ciari, F. Moving toward a More Sustainable Autonomous Mobility, Case of Heterogeneity in Preferences. Sustainability 2023, 15, 460. https:// doi.org/10.3390/su15010460 Academic Editors: Qixiu Cheng, Kai Huang, Yongxiang Zhang and Yu Yao Received: 30 November 2022 Revised: 19 December 2022 Accepted: 23 December 2022 Published: 27 December 2022 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/licenses/by/ 4.0/). sustainability Article Moving toward a More Sustainable Autonomous Mobility, Case of Heterogeneity in Preferences Iman Farzin 1 , Mohammadhossein Abbasi 1 , El ˙ zbieta Macioszek 2, * , Amir Reza Mamdoohi 1 and Francesco Ciari 3 1 Transportation Planning Department, Faculty of Civil & Environmental Engineering, Tarbiat Modares University, Tehran 14115-111, Iran 2 Department of Transport Systems, Traffic Engineering and Logistics, Faculty of Transport and Aviation Engineering, Silesian University of Technology, Krasi´ nskiego 8 Street, 40-019 Katowice, Poland 3 Department of Civil, Geological and Mining Engineering, Polytechnique Montréal University, Montreal, QC H3T 1J4, Canada * Correspondence: elzbieta.macioszek@polsl.pl; Tel.: +48-32-603-41-50 Abstract: Autonomous vehicles (AVs) have a number of potential advantages, although some research indicates that this technology may increase dependence on private cars. An alternative approach to bringing such technology to market is through autonomous taxis (ATs) and buses, which can assist in making transportation more sustainable. This paper aims at examining the role of attitudinal, travel-related, and individual factors in preferences for a modal shift from conventional cars toward ATs and exclusive-lane autonomous buses (ELABs), exploring the existence of heterogeneity and its possible sources. The proposed mixed logit model with a decomposition of random coefficients uses 1251 valid responses from a stated preference survey distributed in Tehran, in 2019. Results show that there is significant taste variation among individuals with respect to ATs’ travel costs, ELABs’ travel times, and walking distances to ELAB stations. Furthermore, exploring the sources of heterogeneity indicates that women are more sensitive to ATs’ travel costs and walking distances to ELAB stations while they are less sensitive to ELABs’ travel times. Moreover, travel time in discretionary activities reduces the utility of ELABs more than it does in mandatory activities. Transportation authorities can use these findings to establish more effective policies for the successful implementation of AVs. Keywords: autonomous bus; autonomous taxi; mixed logit; preference heterogeneity; shifting behavior 1. Introduction Private vehicle ownership and use has led to many challenges facing metropolises, including threats to public health, air pollution, and congestion. This highlights the need to move towards sustainable cities [1]. In recent years, a growing focus has been placed on new technologies in pursuit of a sustainable urban development pathway [2]. Autonomous Vehicles (AVs), as a new paradigm in mobility, are closer to entering the mass market than ever before in the transportation sector [3,4]. AVs offer a variety of substantial benefits that are expected to revolutionize the transportation industry in the future [5] such as increasing traffic flow efficiency [6,7], allowing optimal use of transport infrastructures [8], reducing fatal accidents [9,10], increasing mobility [11], and development of sustainable and intelligent urban mobility by mitigating the externalities of conventional cars usage [12]. Several studies, however, are concerned about the possibility of negative consequences from these vehicles, including an increase in reliance on private cars [10], a reduction in the share of public transportation [13], and the affordability of purchasing such vehicles based on their expected high price [14]. Autonomous taxis (ATs) and autonomous buses (ABs) can be considered as a possible sustainable solution, as they decrease car ownership and increase vehicle occupancy as well as improve efficiency. ATs and ABs could diminish these detrimental effects and lead to an enhancement in transportation system performance. A Sustainability 2023, 15, 460. https://doi.org/10.3390/su15010460 https://www.mdpi.com/journal/sustainability