Integrating Shared Autonomous Mobility into the U.S. Transportation System: An Equity, Economic, Ethical, and Environmental Assessment
The transportation sector will experience a significant shift with the advent of automated vehicles. As the new technology emerges, shared automated mobility is a potentialopportunity to improve equity, access, and sustainability at potentially lower costs. Automated vehicles and shuttles are agile for dynamic routing and can make use of the existing transportation infrastructure, but operating costs, environmental impacts, and social outcomes remain uncertain.
This dissertation advances the understanding of shared automated mobility when integrated with public transportation and when replacing regional air travel. The first study models unmet service need based on transit dependence and sociodemographic information to assess operation costs of shared autonomous vehicles (SAVs) and autonomous shuttles as a part of a public transit system in southwestern Pennsylvania. Analysis revealed SAVs having the lowest for cost per passenger-kilometer traveled (PKT) ranging from $0.77/PKT to $0.90/PKT. SAVs also had the lowest costs per vehicle kilometer traveled (VKT) with $/VKT between $2.15 and $2.28. Results suggest it is feasible to operate SAVs and shuttles into a public transit system at, on average, lower costs than buses. The tool developed in the first study is used in the second study for different-sized cities and transit systems across the United States to determine if there any unique characteristics of cities and public transportation infrastructure SAV public transportation integration and provided insight into service parameters that lead to the cost-efficient operation of shared automated mobility in different public transit systems. In New York City, there were ten Census Block Groups (CBGs) identified as locations for shuttle service. On average these CBGs experienced a 13% improvement in transit access and costs $1.1 million per CBG on average. In the second largest system, Chicago, two census block groups were most costefficiently served by shuttles with a mean cost of $869,000 per CBG for service. One of the midsized cities in this study, Minneapolis-St. Paul saw an 18% improvement in transit access for CBGs served by a small SAV fleet. On average adding SAV service in this city cost approximately $179,000 per CBG. Finally, Pittsburgh was compared to our other cities and had the greatest increase in transit coverage at 315% for SAV service in 4 CBGs. New service for Pittsburgh cost approximately $168,000 per CBG. There are, however, certain conditions where it is still most cost-efficient to add transit access with more conventional modes like bus and rail. The third study assesses to operating costs for trips via shared autonomous electrics vehicles (SAEVs) compared to regional air travel. Ninety-seven of the most common regional aircraft routes were identified as prospective candidates representing approximately 1.2 million flights annually. When the levelized operating costs of SAEVs, privately owned vehicles are regional flights were compared, SAEVs were shown to be the most cost effective and emit the least CO2. SAEVs were found to be less expensive than planes, costing $0.33 versus $12.22 per RKT. SAEVs displayed cost parity with privately owned vehicles while cutting emissions by 39% on average, signaling the prospect of achieving economic and environmental efficiency through intercity shared autonomous mobility services. The final study explores the ethical responsibilities of engineers that contribute to the development and deployment of AVs. While uncertainty surrounds the AV space as a result of technological novelty, engineering ethical canons provide guidelines for engineers to follow. In its totality, this dissertation improves our understanding of the cost, social, and ethical challenges associated with shared automated mobility in different use cases to better inform AV deployment policy and decision making.
- Civil and Environmental Engineering
- Doctor of Philosophy (PhD)