Assessment of the autonomous vehicles impacts on urban mobility and urban form

Abstract

The advent of automobiles profoundly influenced the development of cities in the 20th century, and in recent years, substantial investments by automakers and technology-leading companies in vehicle automation technologies, alongside the release of autonomous driver-assistant features, pilot projects, and the booming volume of studies, signal that Autonomous Vehicles (AVs) have the potential to reshape 21st-century urban mobility and urban form. In today's rapidly evolving world, urban mobility plays a critical role in promoting development in cities. As urban areas continue to grow and evolve, there is an increasing need for efficient and sustainable transportation systems that can accommodate the needs of a rapidly changing urban landscape. Enhancing transportation technology aims to improve the safety, comfort, sustainability, and effectiveness of trips. The benefits of AVs extend beyond mere convenience, promising enhanced safety, reduced traffic congestion, and positive environmental impacts. Additionally, the prospect of driverless taxis, changes in car ownership dynamics, and the synergy between AVs and electric vehicles underscore the multifaceted advantages. However, without comprehensive planning and timely and well-designed regulatory frameworks, AVs could also result in various disruptions and unprecedented challenges in urban mobility and form. Therefore, preparing for the impacts of AVs on urban mobility and urban form is crucial, particularly as municipalities and governments typically develop urban and transportation master plans with 15-25 year horizons. Timely and well-designed policies could maximize the advantages and minimize the drawbacks of these newly emerging technologies. Conversely, inadequate planning and the absence of robust policies could lead to significant monetary and temporal losses due to the uncertainties surrounding AVs. Therefore, understanding and predicting the impacts of AVs are crucial for urban and transport planners and policymakers to make informed decisions and mitigate potential adverse effects. Automotive industry experts claims that the next 10 years' developments in the automotive industry will be much more transformative than it was in the last 50 years. The automotive industry is radically changing by megatrends such as autonomous driving, connectivity, electrification, vehicle sharing, and shifting consumer preferences, and will enter a completely different path by 2030. Considering all these factors, and the features AVs will bring along, the emergence of these vehicles is expected to revolutionize urban mobility in the short to mid-term and urban form in the mid to long-term by introducing new mobility options. The potential impacts of AVs on urban mobility could be complex and twofold. AVs are expected to reduce travel time, improve safety, and provide more comfortable and convenient modes of transportation, transforming individuals' travel behavior and mode choices. These outcomes could induce individuals to own personal AVs and reduce their interest and reliance on public transportation, potentially leading to more traffic congestion and less sustainable outcomes. Conversely, timely and well-designed policies and incentives that popularize shared modes of AVs, such as using them as feeders for public transportation, could decrease personal car ownership rates and foster a culture of shared transportation, resulting in less congestion and more sustainable outcomes. AVs could impact urban form in two opposite ways. On one hand, AVs could enable passengers to work or rest during travel, making long commutes less burdensome and potentially prompting relocations to larger or more affordable homes further from workplaces, thus increasing urban sprawl. On the other hand, shared AV modes could reduce the need for parking spaces, making central locations more attractive and sparking re-urbanization and re-densification. The interdependence between transportation and residential locations is a crucial aspect of urban life, with each influencing the other reciprocally. The transformation of transportation demand is largely driven by the evolution of residential and job location patterns, a relationship commonly referred to as the chicken-and-egg problem in the context of land use and urban transport. Despite an exponential increase in the volume of published journal articles, conference papers, reports and other materials on various aspects of AVs, significant gaps remain in understanding their potential challenges and disruptions. These include required transformations or modifications in road infrastructures, user perceptions and attitudes, road safety, transport operations' effectiveness, and emissions. There are still many uncertainties about different modes of AVs, particularly their shared modes (SAVs), such as whether they will be easily accepted by the public, their effect on personal car ownership rates, and potential shifts in individuals' travel behavior, which depend on several factors. The majority of existing studies have been conducted in developed countries, with few or no studies focusing on developing countries such as Turkey. Moreover, the great majority of the existing knowledge in this field is derived from or localized to developed countries, leaving data on developing countries scarce or non-existent. Meanwhile, considering the existence of hundreds of millions of active passenger cars running around globally with an average lifespan of approximately 20 years, the transition to AVs will be gradual. Consequently, it is imperative to analyze the different phases of AVs' transition in the presence of traditional modes continuously and in advance, so the required policies can be calibrated early to guide toward the desired AV-dominated future. The interdisciplinary nature of AVs subject, combined with significant investments by automakers and technology-leading companies, has led to a surge in research publications. Considering the massive volume of research studies, published journal articles, conference papers, book chapters, reports, and other materials, it is essential to periodically synthesize and summarize these studies to map the domain's landscape and its evolutions and key characteristics, pinpoint gaps, and develop a roadmap to detect potential trends. Therefore, this dissertation employs scientometrics analyses to depict a comprehensive review of the literature on AVs with a particular focus on the place of Urban Transportation Planning (UTP) and the place of developing countries in this field. This has been achieved by visualizing and mapping the scientific landscape of the domain at a holistic macro-level, along with the analysis of the literature from the perspective of UTP at a meso-level. This approach aimed to provide insights into research trends and future directions, particularly in the context of UTP. As the second chapter of the dissertation, this part aims to contribute to the literature by focusing on the UTP aspect of AVs, addressing the current gap and aiding in the preparation for the impending technology. In the third chapter, data obtained from a meticulously designed survey distributed in Istanbul, Turkey, was used to analyze the potential factors influencing individuals' willingness to own an AV if they were released to the market. Additionally, this chapter examines factors that might affect individuals' decisions to relocate to a farther, but more affordable or larger residence due to the convenience of travel brought by AVs. To achieve these analyses, discrete choice modeling techniques were employed, and numerous multinomial logit models were estimated to identify significant determinants. In the fourth chapter, four hypothetical designed scenarios, each represents a horizon of AVs' progression were presented to the subjects. This chapter carefully analyzes the factors influencing individuals' willingness to choose a particular mode of transportation. Additionally, this chapter investigates potential shifts in mode choice behavior in the presence of different AV modes, alongside conventional vehicles through various phases of AVs evolution. Mixed logit models were found to be the most efficient models for these analyses. The study also analyzes diverse demographic and socio-economic groups to determine the factors influencing their decision-making processes, considering the potential for renouncing personal car ownership under various shared AV scenarios. Utilizing a dataset collected from Istanbul, Turkey, this study enriches the literature from the perspective of a developing country. In conclusion, this dissertation has provided a comprehensive analysis of AVs' potential impacts on urban mobility and form, emphasizing the importance of UTP in maximizing benefits and mitigating negative outcomes.