Perceived benefits and constraints in vehicle automation: Data to assess the relationship between driver's features and their attitudes towards autonomous vehicles

This data article examines the association driver's features, perceptions and attitudes towards autonomous vehicles (AVs). The data was collected using a structured self-administrable and online-based questionnaire, applied to a full sample of 1205 Spanish drivers. The data contains 4 parts: the full set of bivariate correlations between study variables; descriptive statistics and graphical trends for each main study variable according to gender, age group and city/town size; and, finally, the dataset for further explorations in this regard. For more information, it is convenient to read the full article entitled “Perceived safety and attributed value as predictors of the intention to use autonomous vehicles: A national study with Spanish drivers” [1].


Data
The dataset of this article provides information on a set of demographics, perceptions on autonomous vehicles and crash-related factors of the sample, fully composed of licensed Spanish drivers. Table 1 presents the descriptive information on the items contained in the questionnaire. Fig. 1 presents graphically the full set of bivariate correlations among the three main study factors and individual features of drivers. Table 2 shows the descriptive statistics obtained for the three attitudinal AV-related variables included in this data article (i.e., perceived safety, value attributed and intention to use), both for the full sample and split by gender, and Fig. 2 specifically shows trends on acceptance of autonomous vehicles according to the gender of drivers. Table 3 allows to identify the specific differences between drivers by age through a One-way ANOVA (Analysis of Variance), summarizing the statistical differences among different age groups for these variables, and Fig. 3 graphically shows the mean score reported by each age group.
Finally, Table 4 presents the mean scores reported on perceived safety, value attributed and intention to use autonomous vehicles (AVs) according to the size of the town/city of residence of participants. In addition, this article includes, as supplementary materials: the questionnaire (form) used for performing the study, and the dataset (SPSS -.sav), that will allow researchers to perform additional tests and comparisons using the entire set of measured variables. It is important to remark that no inferences, interpretations or conclusions on the data are presented in this paper, but are available in the complementary article [1]. Value of the Data This data can be useful since it provides information on how Spanish drivers perceive the safety and value of the autonomous vehicles (AVs), and their intention to use them. This data can be used by other researchers, road safety practitioners and market stakeholders to identify demographicbased patterns and profiles of potential users of AVs, according to the trends and differences identified in this study. The perceived safety and value attributed to autonomous vehicles can be analyzed according to different user-related features, such as their age, gender, educational level, city/town size and occupation, variables also contained in the annex dataset. Additionally, the data contained in this article can be compared with other samples/studies, in order to examine means, associations and trends on perceptions and attitudes towards the autonomous vehicles (AVs) among drivers.

Participants
For this cross-sectional research, it was collected and analyzed the data of a nationally representative sample of n ¼ 1025 drivers from the 17 autonomous communities of Spain.
In accordance with the pursued analyses and some previous research experiences dealing with different gender and age-based groups of population [2,3], the data was analyzed considering both the full sample and specific sub-groups built up bearing in mind these individual features, already supported by literature as potential key factors on decision-making in urban mobility-settings [4e6]. Thus, for making comparisons in the study variables, the full sample was divided: a) by gender (538 females, and 667 males); and b) in five intervals, composed as follows: <25 years (n ¼ 113, composing 9.4% of the sample); 25e35 years (n ¼ 271, composing 22.4% of the sample); 36e45 years (n ¼ 359, composing 29.8% of the sample); 46e55 years (n ¼ 326, composing 27.1% of the sample); and >55 years (n ¼ 136, composing 11.3% of the sample). Additionally, it was taken into account the size of the town/city of residence of the driver, as recent evidences suggest that attitudes towards autonomous vehicles may differ according to the place of residence [6] and other settings related to driving habits and lifestyle [3,4]. Notes: Negative (-) items have been recoded for factor scoring.; 1 n¼ sample size; 2 Min¼ lower value; 3 Max¼ higher value; 4 Mean¼ Arithmetic mean (average); 5 SD¼ Standard Deviation.

Questionnaire
For the original research [1], the questionnaire was administrated exclusively in Spanish (professionally translated for publication) and consisted of three main sections. The first part asked about individual and demographic variables, such as age, gender, city/town of provenance (and its size) and main current occupation.
In the second part, participants were asked about their level of interaction with Information and Communication Technologies (ICTs) in a scale between 1 (less interaction) and 5 (more interaction). It also contained a short form about driving-related issues such as: crashes suffered while driving conventional cars (along the last 3 years), driving tenure (years licensed) and driving patterns, including the type of vehicle most frequently driven, number of kilometers (Km) a day, and their average frequency (times a week), in order to estimate the driving intensity.
As for the third part of the research questionnaire, a 5-item scale (a ¼ 0.735) was used for measuring the perceived safety of autonomous vehicles among drivers. It asked the level of agreement of drivers with statements related to the safety features of AVs through a Likert scale between 1 ¼ total disagreement to 5 ¼ total agreement. In order to assess the value attributed to the AV for traffic sustainability and road safety, it was applied a 5-item scale (a ¼ 0.739), aimed at obtaining the appraisal of participants on topics related to the impact of AVs on better and safer transport dynamics, using a Likert form ranging from 1 to 5. Finally, and in order to measure the intention of using autonomous vehicles, a 12-item (a ¼ 0.929) Likert scale (1 ¼ total disagreement to 5 ¼ total agreement), designed under the guidelines suggested by Van Der Laan et al. [7] was applied. It asked participants about different situations in which they would decide (or not) to use an autonomous vehicle, considering the potential benefits seen on it by them. The full set of items included in the questionnaire and their descriptive statistics are shown in Table 1.

Statistical analysis
First of all, basic descriptive analyses (i.e. means and standard deviations of the study variables) were obtained, and bivariate correlation analyses were carried out, in order to establish measures of association between pairs of these factors. Further, and with the aim of comparing the scores obtained on attitudes towards autonomous vehicles, One-way ANOVA (Analysis of Variance) was performed for the categorical factors: 1) gender; 2) age group -using five intervals, as described in the sample section;  and 3) width of the city of provenance. The full set of variables and cases composing the study is available in the annex dataset.