The influence of household characteristics on the purchase of clean cars. The case of Spain

This paper determines the socioeconomic characteristics of Spanish households that use clean cars, with the aim of identifying how these characteristics influence the market penetration of these vehicles. This study is one of the few in the literature that analyses the characteristics of car users based on a broad sample of data, that is representative of 11.5 million households. The results allow us to identify socioeconomic challenges and opportunities regarding the goal of replacing combustion vehicles with clean vehicles. We estimate a logit model finding that high-income households are 29.3% more likely to use a clean vehicle than medium–low-income households. On the contrary, the gender and age of the household"s main breadwinner present opportunities: if he is a male, it is more likely to use clean vehicles than if she is a woman, and households whose main breadwinner is over 55 or under 30 are more likely to use it. These results provide guidelines for a better design of public policies aimed at decarbonizing the transport sector through the replacement of conventional vehicles by clean ones. To do so it is important to consider the features of the social reality in which that objective is to be achieved

To Drive or not to Drive - A Critical Review regarding the Acceptance of Autonomous Vehicles

With the advent of autonomous vehicles (AVs), research has put much effort in investigating the factors relevant for the acceptance of this new technology. In order to identify, critically assess, and combine extant findings, we performed a structured literature review regarding the acceptance of self-driving vehicles. Results of this review spanning 58 articles include (1) a comprehensive AV acceptance framework outlining significant factors across three areas: individual characteristics, vehicle characteristics and policy/society. We also (2) analyze the operationalization of relevant constructs and items in the identified studies as they strongly diverge in extant literature. This new level of detail helps researchers and practitioners to pervade and compare the AV acceptance research in-depth. Additionally, we contribute to the AV research stream as we (3) identify possible future research avenues, which we examine regarding content, method, and focus

Autonomous vehicles between anticipation and apprehension: Investigations through safety and security perceptions

Due to the ongoing enormous infrastructural developments and car ownership culture in Qatar, it could be one of those countries to introduce Autonomous Vehicles (AV) technology at the early stages. Therefore, this study surveyed a number of residents at the State of Qatar to improve our understandings of their perceptions regarding overall safety of AV (General_safety), safety due to the fact that AV could eliminate human errors (Human_errors), safety due to the interactions between Human-Driven Vehicles (HDV) and AV (HDV-AV_interactions), performance in harsh environmental conditions, security, comfort level, travel time, congestion and operational costs. In addition, the study uncovered the relationships of public perceptions towards AV and some other contextual factors with the willingness to adopt it in the future. To study these relations, we relied on a Structural Equation Modeling. Overall, the results showed that respondents had higher and positive perceptions regarding “General_safety” and “Human_errors”, however, they were more concerned about “HDV-AV_interactions” and its security. In addition, individuals’ preference to shift to AV in the future was positively correlated with their perception level of “General_safety”, “Human_errors”, Comfort and Travel_time. Regarding ethnicity of the respondents, non-Arabs reported higher concerns regarding AV security, compared to Arabs. Furthermore, interestingly the results revealed that individuals having higher knowledge about AV technology had more concerns on “General_safety” and “HDV-AV_interactions”, while they had positive perceptions that AV could eliminate human errors. The findings from this study are anticipated to allow AV manufacturers and other relevant authorities to enhance public confidence towards AV technology by targeting different sub-groups through particular safety or security awareness campaigns.The Qatar–Japan Research Collaboration Application Award [M-QJRC-2020-8] from Qatar University. Open Access funding provided by the Qatar National Library

Interrelationships among predictors of automated vehicle acceptance: a structural equation modelling approach

The study investigated the interrelationships between the UTAUT2 (Unified Theory of Acceptance and Use of Technology) constructs predicting intentions to use driverless automated shuttles. Survey data was gathered from individuals physically experiencing an automated shuttle in a mixed traffic environment on public roads in Trikala (Greece) as part of the CityMobil2 project. Structural equation modelling showed that intentions to use automated shuttles were most strongly driven by hedonic motivation, followed by performance expectancy and social influence. Performance expectancy mediated the relationship between effort expectancy and behavioural intention. This means that people's expectations of how difficult automated shuttles will be to use and their intentions to use them can be explained through their expectations around how these vehicles will perform. Technology savviness was a negative moderator of the relationship between social influence and performance expectancy and facilitating conditions, respectively. Tech-savvy individuals rely less on their social networks to nurture their beliefs that automated shuttles are useful and to have the necessary resources to use automated shuttles. Car use was a negative predictor of the intention to use automated shuttles. Future research should revisit the interrelationships between the UTAUT2 constructs and apply (quasi-) experimental studies to unravel the temporal interaction between constructs.Relevance to human factors/Relevance to ergonomics theoryThe study investigated the interrelationships between the UTAUT2 (Unified Theory of Acceptance and Use of Technology) constructs predicting intentions to use driverless automated shuttles. Survey data from individuals physically experiencing an automated shuttle in Trikala (Greece) as part of the CityMobil2 project was analysed by structural equation modeling. Examining the interrelationships between the UTAUT2 constructs enables us to identify underlying beliefs and devise adequate strategies to promote automated vehicle acceptance

Essays on the econometric analysis of the use of transport and of the public policies for its sustainability

La reducción de la contaminación del sector transporte es fundamental para la transición energética y lograr los objetivos de la agenda 2030. En esta tesis doctoral, a través de tres ensayos, nos hemos centrado en investigar las medidas de política pública que promueven el uso de Transporte Público como alternativa ambiental al automóvil privado y aquellas que promueven la sustitución de vehículos de combustión por vehículos limpios (híbridos y eléctricos). Específicamente, los dos primeros ensayos evalúan el impacto de la política de subsidios a la tarifa de transporte público a los jóvenes y a las personas mayores sobre el bienestar de los hogares beneficiarios (equidad). En cuanto al segundo ensayo, también se ocupa del análisis del impacto de los subsidios del transpote público urbano en la eficiencia económica. Ambos ensayos se centran en analizar el caso de la región de Madrid. Se utilizaron las técnicas econométricas de Diferencias en Diferencias y de Regresión en Discontinuidad respectivamente. El tercer ensayo se centra en identificar las características socioeconómicas y demográficas que influyen en la compra de vehículos limpios (híbridos y eléctricos) mediante la técnica econométrica de regresión logística para toda España. Los ensayos utilizaron datos de la Encuesta de Presupuestos Familiares del Instituto Nacional de Estadística. Los tres trabajos han llegado a interesantes resultados: las políticas de subsidio analizadas logran los objetivos de equidad económica ya que benefician a los grupos más pobres de la sociedad. No obstante, los mayores beneficiarios de estas políticas son los hogares con niveles de renta media-alta (subsidios para jóvenes) o niveles de renta alta (subsidios para personas mayores), lo que sugiere la necesidad de incluir criterios de renta para esas políticas de subsidio. En relación a la eficiencia económica de los subsidios al transporte público urbano, los resultados muestran que aun cuando los subsidios son muy generosos, como es el caso de los subsidios para mayores de 65 años, si los beneficiarios están ocupados, y por lo tanto tienen que trasladarse por razones laborales, el aumento del precio relativo de los combustibles, derivado de la medida de política analizada, no es suficiente para incentivar la sustitución del uso del vehículo privado por el transporte público. En cuanto a la penetración de vehículos limpios en el mercado, los resultados muestran que existen barreras económicas a su penetración en el mercado que están relacionadas con el nivel de renta de los compradores potenciales y otras variables estrechamente ligadas al nivel de renta. Sin embargo, también existen características socioeconómicas que son ventajosas para el crecimiento del sector de vehículos limpios, como la edad y el género de los compradores potenciales. Las políticas públicas dirigidas a promover la compra de vehículos limpios deben considerar el primer aspecto y, por lo tanto, las ayudas económicas otorgadas para comprar un automóvil limpio deben estar vinculadas al nivel de rentas del beneficiario. Estos son temas de gran interés académico y social que contribuyen al análisis económico del uso del transporte y diseño de las políticas públicas que fomentan su sostenibilidad social y ambiental

Walking and cycling in an automated future: a Dutch-Australian comparison

Technological mobility innovation is poised to accelerate, with the advent of Automated Vehicles (AVs) predicted to improve road safety, reduce transport costs, increase access to mobility, and to hasten Electric Vehicle adoption. Although AV technology is evolving rapidly, consumer preferences for AV ownership and use, as well as the potential impacts of AVs on walking and cycling are not well understood. This research compares contextual conditions, attitudes and AV adoption likelihood in two contrasting locales: car-friendly Sydney, Australia and walk/cycle-friendly The Randstad, Netherlands. The research focuses on travel behaviour for short trips, where walking and cycling have traditionally held an advantage over motor vehicles. The research uses a mixed-methods approach that uses analytical methods (a comparison of locales), qualitative methods (semi-structured interviews) and quantitative methods (discrete choice analysis). The qualitative research reveals that Dutch participants feel that all road users have the same right to use road space, and should have the same expectation of safety. In contrast, Australian participants express impatience with “other people” walking, and score the importance of safety for car occupants as higher than for non-occupants. This highlights that attitudes towards non-car modes in some localities present a risk factor for further marginalisation of walking and cycling in an AV future. The quantitative research reveals that mode choice retention is highest for those who currently cycle, and that protected bicycle infrastructure is likely to encourage bicycle use in an AV future. Walking is also encouraged by the provision of separated infrastructure and is more popular for shopping in the Netherlands, where trips are more frequent and cargo-carrying requirements are lower

Mobility in the Advent of Autonomous Driving – Toward an Understanding of User Acceptance and Quality Perception Factors

Recent advancements in intelligent technologies and sensor-based data collections pave the way for autonomous driving and facilitate a radical transformation of today’s mobility. Based on auspicious market projections, traditional automotive manufacturers and technology companies invest heavily in the development of autonomous vehicles (AVs). In addition to the profits that the industry expects from self-driving vehicles, this new type of mobility should also solve societal issues like reducing traffic accidents and fatalities by eliminating human driving errors. More efficient autonomous driving is expected to bring improvements in terms of fewer congestions and less fuel consumption, thereby reducing greenhouse emissions. Besides, AVs pledge to entail advantages for their users. Specifically, they increase mobility for the disabled and the older generation. In contrast, younger passengers associate autonomous driving with improved productivity and an enhanced hedonic experience as non-driving activities, such as working or watching a movie, are made possible. Contrary to the above expectations, people also raise concerns regarding self-driving vehicles. They are worried about whether the sensors and systems can correctly interpret complex environmental conditions. Above all, there are doubts whether the technology, even being intelligent, can react appropriately in critical traffic situations made up of humans who sometimes behave unpredictably. In case of unavoidable traffic accidents, ethical questions come into play regarding how the vehicle makes decisions that could result in a person being injured or killed. Finally, the new and sophisticated technology could have vulnerabilities that can be exploited by cybercriminals or allow unauthorized third parties to obtain passenger data. Motivated by the anticipated improvements that AVs entail and the breadth of factors that might influence their adoption, a large body of research investigating relevant adoption factors has accumulated. In order to collect, organize, and combine extant findings, research paper A conducts a structured literature review on the acceptance of autonomous vehicles. Based on 58 articles, it develops an AV acceptance framework consisting of individual user characteristics, vehicle characteristics, and political/societal elements. The framework indicates for each factor whether available research results identify the effect as either positively or negatively significant. Thereby, the paper also sheds light on diverging construct operationalizations, aiming to support researchers in comparing available findings. Eventually, paper A proposes future research avenues across various themes and methods, which build a foundation for further research pursued in this dissertation’s subsequent papers. However, solely balancing significant against non-significant results can come to wrong conclusions since the sample size alone can lead to varying significance levels. Because of this, paper B builds on the literature review and conducts a meta-analysis to include further quantitative analyses. It calculates the mean effect sizes for each AV acceptance factor based on published research results. By doing so, the paper identifies attitude, perceived usefulness, efficiency, trust in AVs, safety, and subjective norms to correlate most strongly with the behavioral intention to use an automated car. A subsequent moderator-analysis shows that almost all acceptance factors are influenced by the study’s methodology and location, the AV’s level of automation, and the examined ownership model, i.e., private cars, car sharing, or public transport. In doing so, paper B observes that most of the available research is on privately owned AVs and hence lacks to assess public as well as shared automated mobility. To fill this gap, paper C investigates characteristics relevant for automated mobility as a service (AMaaS). Based on 23 exploratory interviews with the general public, the paper derives a set of AMaaS requirements. Mobility experts sort these requirements based on commonalities so that a cluster analysis can conceptualize the expected AMaaS characteristics from a practitioner’s view. The paper identifies traffic safety, information privacy, cybersecurity, regulations, flexibility, accessibility, efficiency, and convenience to be relevant service characteristics. It discusses each required characteristic and thereby delineates the constructs’ scopes so that subsequent research can build appropriate measurement instruments. Besides, paper C discovers strongly diverging priorities regarding the respective service characteristics when comparing the potential users’ conversation shares with the experts’ relevance ratings. Paper D builds on the qualitative results of paper C as it develops and validates a hierarchical quality scale for AMaaS. The paper proposes a theoretical model and operationalizes the previously identified service characteristics. Throughout multiple empirical studies with 1,431 participants, the proposed quality scale is refined iteratively until satisfactory psychometric properties are achieved. Nomological validity ensures the scale’s predictability. Paper D progresses research from focussing on the mere acceptance of autonomous driving to the user’s quality perception, which significantly influences user satisfaction and the success of AMaaS. This, in turn, is necessary to realize the promised benefits of autonomous driving in a sustainable manner