1. Introduction
The automation of transport is expected to bring a shift in mobility. This will significantly affect the way of life for many people [
1] and will serve as a key aspect determining the competitiveness of transport companies, affecting their future position in economic, environmental, and social spheres [
2,
3]. It is not surprising that the automation of transport has become a priority thematic area at the global level, which is reflected in several international research programs (e.g., Horizon 2020). A few of the benefits expected from the automation of transport are increased security and efficiency, major comfort for users and professionals, and enhanced social inclusion and accessibility [
4].
In this context, project AUTOMOST (2016–2020) [
5] was implemented. The project’s aim is to analyze the technical and psychological barriers along the path towards implementation of autonomous vehicles, specifically, autonomous buses. The present report deals with the psychological barriers only, analyzed through data collected from focus groups (FGs).
Progress in the field of autonomous driving, which is understood as the capacity of a vehicle to drive by itself, is a fact. Niche manufacturers have estimated that by the 2020s, fully autonomous vehicles will be available on the market [
6]. The development of this technology is fostered by European and other various international institutions due to the potential of this technology to improve security, increase fuel consumption efficiency, and save time. Indeed, autonomous vehicles (AVs), as well as electrification and vehicle sharing, can be the next big change in the field of mobility [
7].
However, while autonomous vehicles may be available on the market in the 2020s, it will take at least another three decades until these vehicles receive sufficient acceptance and become adequately reliable and affordable enough to account for 50% of the global fleet [
4]. The barriers that are required to be overcome in order to introduce autonomous vehicles to the road and the consequences of this development are uncertain, and several researchers have analyzed this previously [
2,
4,
8]. The positive and negative aspects of these reported technologies from these studies—and in certain others conducted on autonomous buses [
9,
10,
11], a topic for which the literature is scarce [
12]—are summarized in
Table 1.
In addition to the studies mentioned above and summarized in
Table 1, several other studies have been conducted regarding the actual and potential technical, administrative, or legal constraints and benefits of autonomous driving [
13,
14,
15], or regarding the motivations for owning an autonomous vehicle [
16]. However, limited focus has been paid regarding perceptions of autonomous vehicles, particularly regarding perceptions of autonomous buses, i.e., how individuals feel regarding the possibility of being transported by a driverless public transport means other than metro rail or taxi, or whether factors affecting the public perceptions of autonomous vehicles are similar to those affecting autonomous buses.
The fact is that the limited number of scientific studies conducted on autonomous buses deal only with the cost analysis of the services [
12]. As stated by Shin et al. [
15], limited data are available on how consumers value emerging vehicular technologies. According to the reviewed literature, no studies are available which have used the FG technique in order to identify the factors influencing the adoption and usage of autonomous buses.
A focus on autonomous buses generates alternative perspectives. For instance, several researchers have predicted that autonomous cars will lead to a general reduction in the travelers’ value of time, as their occupants will be able to perform other activities (leisure or productive) while traveling [
17], in addition to the reduction of stress, among other advantages. However, this would not be the case with autonomous buses, as it could be argued that public transport is already offering these possibilities. Therefore, it all turns out to be about efficiency. It is in this context that the UITP’s (Union Internationale des Transports Publics) position paper pleads for a future of shared mobility, with driverless car fleets reinforcing the public transport network, as illustrated in
Figure 1. In this sense, autonomous public transportation can provide the key to a
sustainable mobility solution [
7].
The present report describes the results of the two FGs which were developed in the framework of project AUTOMOST [
5], with the objective of outlining all the aspects that could affect the implementation of autonomous vehicles, particularly autonomous buses, and exploring which of these aspects could be more interesting.
2. Methodology: The FG Approach
Focus groups may assist in capturing insights into several issues ranging from decision making to policy or service development [
18], and, of course, behavior. In the AUTOMOST project [
5], the researchers expect to determine the level of acceptability among individuals for an innovative technology applied to a means of transport other than a car, for example, buses. The objective of the project was to identify the main objections to the usage of autonomous buses and to generate ideas regarding methods to overcome these objections in order to design a strategy to introduce self-driving buses onto the market. The main difference between the FG approach and the one-to-one interview approach lies in the fact that while the latter aims to probe experience, an FG is intended to serve as a group of individuals who are able to generate ideas [
19].
The FG approach may be defined as a semi-structured group session, moderated by a group leader, and held in an informal setting, with the purpose of collecting information on a designated topic [
20]. Unlike one-to-one interviews, FG debates are more accommodating in that they allow for the generation of novel ideas [
19]. Focus group debates are used widely in different fields of research to obtain qualitative data [
21].
Merton and Kendall [
22] developed the FG technique as a key element for studying human behavior and sociology. Since the time it was originally developed, the FG technique has been used to conduct market analysis, evaluation of product acceptance, analysis of the structure and organization of companies, health research, analysis of social issues, etc. [
23].
A focus group interview is a sort of group interview in which, owing to the communication among the participants, knowledge and data are generated [
24]. Interaction among the participants is the key component of this technique and another main factor which differentiates FGs from one-to-one interviews. This type of group exercise is quite effective in assisting individuals to explore and clarify their thoughts and opinions.
Nevertheless, the analysis and utilization of FGs is a complex task, and although it generates qualitative information which is relevant and innovative, it does not offer statistically significant results [
24], which is the reason that the application of this technique is not always advisable. However, as stated by Krueger and Casey [
18], FGs are ideal when exploring perceptions, attitudes, and thoughts among individuals regarding a plan, policy, or tendency which will affect them in the future, and also when searching for novel ideas, concepts, and issues related to a new topic. Both of these objectives were fulfilled and are included in the present report, i.e., a better understanding of the perceptions among people regarding the implementation of autonomous cars and buses in a manner that raises novel questions and factors related to this relatively new topic.
The research described here was based on two FGs, the same number of FGs used by other authors to support their own qualitative analyses [
25,
26,
27]. In order to correctly develop both of the FGs, they were organized in accordance with the following guidelines provided by Kitzinger [
24], and Krueger and Casey [
18]:
It is advisable to organize the FG with the number of participants ranging between 6 and 10 [
20]. This number should represent the target population to the fullest extent possible. Besides, it is convenient that the focus group be diverse in terms of the variables that affect the topic under analysis the most. In the case described in the present report, each group consisted of eight participants, and the variables considered to ensure diversity were age and gender; according to different authors [
28], these are the characteristics that influence the acceptability of autonomous driving the most. Each group consisted of a man and a woman aged between 20 and 30 years, between 30 and 40 years, 40 and 60 years, and 60 and 80 years.
The sessions should be conducted in a relaxed atmosphere, where the participants feel at ease, with all of them seated in a circle for convenient interaction. One or two coordinators or moderators should introduce the topic, encourage communication among the participants, lead the discussion, and raise questions. Two moderators intervened in the FGs described in the present report. A brief introduction of the subject was presented to the group at the beginning of the session, in order to provide information on the current situation, while explaining that they could ask for clarifications.
After the introduction of the subject, all the participants should talk freely regarding what they consider appropriate, to encourage the emergence of novel concepts and to determine the priority issues required to be taken into consideration. Nevertheless, in order to gain the best possible results from the FG, the moderator(s) should raise those important issues that have not been brought up naturally during participant discussions. Besides, the moderator(s) must attempt to have everyone engaged, preventing a particularly dominant participant from overtaking the conversation and crowding out other participants [
19]. In the case included in the present report, the moderators used notes based on the information provided in
Table 1. Therefore, the factors already analyzed by existing literature on autonomous driving (described in
Section 1 and summarized in
Table 1) were the starting points for the FG. This should ensure the added value of the results compared to other studies.
Ideally, the sessions should be recorded and subsequently transcribed. In the case at hand, the sessions were recorded, while a person took notes that were later transcribed. The sessions lasted for 1.5–2 h. Once the files with the recordings were extracted, they were transcribed word by word in order to better grasp the emotions and the intensity of the comments, and the different ways of thinking, which would otherwise be impossible to grasp.
Once the FG plans have been conducted, consideration of whether the saturation point has been reached should be done [
18]. According to the authors in Reference [
18], saturation is a term used to describe the point where a range of ideas have been raised on a recurring basis and no new information appears. If this point has not been reached, it would be necessary to program more FGs. However, it is always advisable to carry out more than one FG in order to conduct an analysis across groups. In the case described here, two FGs were planned in principle, the first one in Madrid and the second one in Malaga. Most ideas and thoughts were raised in Madrid and corroborated in Malaga. Actually, in this second FG, several new concepts appeared but it mostly consisted of repeating the same notions in different words. Therefore, it was concluded that the saturation point was reached in Malaga and there was no need to program a new FG.
3. Results
All the concepts that emerged on the basis of the transcriptions were defined and conceptualized. Automated driving is a novel and futuristic topic. The discussions focused on the effects (positive or negative) that autonomous driving technology would cause and the barriers for the development of this technology.
Table 2 and
Table 3 list the positive and negative effects of autonomous driving, divided into five categories: environmental, psychosocial, socioeconomic, effects related to the vehicle or the infrastructure, and the effects related to novel business models associated with autonomous vehicles.
Table 4 describes the relevance of each effect on autonomous vehicles.
Table 5 lists the barriers along the path to the development of autonomous vehicles in general and autonomous buses in particular.
Figure 2 presents the importance given to each of the effects associated with autonomous driving according to the number of times the effect was mentioned during the sessions. It is noteworthy that much importance was given to the psychosocial effects associated with the compliance with rules, which indicated that a greater reliance was placed in machines rather than in people at the time of execution and application of standards (e.g., obeying speed limits and traffic lights). It is also believed that there would be fewer accidents because of a reduction in human errors. Among the disadvantages, the inability to improvise appears to be the most significant. It is also worth noting that the importance was given to novel business models, especially to the fact that autonomous driving would encourage collaborative economy, which is a concept that is becoming increasingly important nowadays. Environmental effects attracted few comments in general, although it is believed that the implementation of autonomous vehicles would have positive outcomes in general. On the one hand, it would promote car fleet renewal, favoring the use of cleaner energy resources. On the other hand, it would lead to more efficient driving, reducing the energy consumption per kilometer.
Figure 3 depicts that the socioeconomic aspects—especially the probable reduction in the number of jobs for drivers—which were among the most important negative attributes stated by the participants in the FGs. Nevertheless, it was agreed in general that these losses in jobs could be conveniently compensated through the creation of skilled employment (
Figure 2).
The importance of each barrier along the path of the development of autonomous driving are listed in
Figure 4. The fear of a new technology that has barely been proven appeared to be the most important barrier. This barrier was well aligned with the other recurrent barriers, such as the feeling of not having control over the driving. Other relevant barriers were those associated with the transition between manual and autonomous vehicles. It was believed that once the entire fleet is autonomous, driving will be safer. However, the coexistence period—where both autonomous and manual vehicles would be circulating together on the road—generated uncertainty, and was, therefore, associated with unsafety and compatibility issues.
Certain legal barriers were stated during the FGs, such as those associated with responsibilities in the event of an accident or those associated with insurance complexities. However, these barriers were not considered crucial, as it was believed that these would be resolved as the technologies evolved. Even the barriers associated with mobility did not appear to be noteworthy. As far as autonomous buses were concerned, the barriers were related to the absence of someone who could physically impose authority, in enforcing payment, informing, or preventing security attacks.
In order to obtain the results that were reported, the FGs held in Madrid and Malaga were jointly addressed. After processing the interventions of each of the participants, 413 relevant comments that fulfilled the objective of the present report were obtained (
Figure 5). Most of these comments (64%) referred to the effects that the autonomous vehicles would have in the future, the positive ones being more frequent (37%) than the negative ones (17%). Forty-six percent of the comments were focused on the barriers along the path of development of autonomous vehicles, especially the barriers related to the perceptions of the lack of safety.
Figure 5 also reveals that the psychosocial and socioeconomic effects of autonomous driving were the most recurrent ones. In addition, autonomous vehicles were positively associated with novel business models and a collaborative economy.
Appendix A provides details regarding the personal characteristics of the individuals who made reference to each of the concepts with their comments.
4. Discussion of Results
The added value of the results presented in comparison to the existing literature (summarized in
Table 1) relies on results including the definition of all the concepts surrounding the implementation of AVs and ABs and their classification, in addition to the definition of novel concepts (highlighted in grey in
Table 2 and
Table 3). Although the research was developed in the framework of a national project, the outcomes obtained are universally applicable and help to understand the barriers to the development of autonomous driving. Furthermore, autonomous buses constitute a topic that has been barely addressed in the literature [
12]. The few existing studies are generally focused on psychological barriers [
9,
10], while this paper offers a more holistic approach.
In any case, there is a need to reflect on the possible limitations and potential extensions of the study presented. In the context of this research, the realization of more FGs would probably not have added new findings, as the saturation point was reached in the second FG. However, the FGs were developed in two Spanish cities and it is possible that if the experiment was repeated in other countries, participants would insist differently on each effect and barrier. For example, in a country such as the USA, which has more permissive laws regarding AVs and which has more experience in testing these technologies [
29], perceptions and psychosocial barriers would probably not seem so important (
Figure 5). Finally, it should be noted that most effects and barriers arise due to the mistrust that new technologies produce. Therefore, it would be convenient and interesting to repeat the study in a few years and analyze the outcomes again, when AVs have been more tested and developed.
5. Conclusions
In the present report, the results of two focus groups conducted in Malaga and Madrid were presented in order to define and evaluate the barriers and potential consequences of autonomous driving. The methodology was proven as effective in determining the key factors surrounding the introduction of autonomous vehicles. The added value of the present report compared to the existing literature is that this report conceptualized all of these factors and their classification into different categories. A convenient structure of the effects and barriers was generated, which assists in understanding the possible consequences of autonomous driving in all areas. In addition, the report illustrates the most positive aspects (e.g., regulatory compliance or promotion of collaborative economy) as well as the most important barriers in the path of expansion of this technology (e.g., lack of experimentation or the complex management of a mixed fleet). However, the good news here is that these constraints can be overcome as the technology begins to penetrate the market [
30].
Finally, in the present report, a topic barely addressed in the existing literature was analyzed, i.e., autonomous buses and their acceptability. All the concepts analyzed will be important for the implementation of autonomous cars and buses and must be considered in the marketing or promotional strategies for these technologies. Given that individuals are still less willing to ride in driverless vehicles than those with human drivers [
10], the outcomes of this paper are clearly relevant.
The present report opens the scope for novel research works in this area of study. With the identification and conceptualization of the major concerns and interests perceived by people and the structuring of their perceptions performed in a logical manner, it would be interesting to conduct massive surveys among the general public or interviews with experts in the field. This would assist in prioritizing and evaluating, in a statistically significant manner, the most important barriers or the most worrying effects along the path of the development of autonomous driving.