Assessing the feasibility of the theory of planned behaviour in predicting drivers’ intentions to operate conditional and full automated vehicles

Guided by the Theory of Planned Behaviour (TPB), this study examined the beliefs underpinning, and feasibility of the factors in predicting, individuals’ intentions to use a conditional (Level 3) automated vehicle (AV) and a full (Level 5) AV. Australian drivers (N = 505) aged 17–81 years (Mean age = 33.69, SD = 18.79) were recruited and completed a 20 min online survey which featured both quantitative and qualitative items. For the quantitative data, two linear regressions revealed that the TPB standard constructs of attitudes, subjective norm, and perceived behavioural control (PBC) accounted for 66% of the variance in intentions to use a conditional AV and 68% of the variance in intentions to use a full AV. Of the TPB constructs, attitudes and subjective norms were significant positive predictors of future intentions to use conditional and full AVs. For the qualitative data, some differences emerged for the underlying behavioural beliefs that underpinned intentions to use conditional and full AVs. For example, having beliefs about control over the conditional AV was identified by many participants as an advantage, while not being in full control of the full AV was identified as a disadvantage. For underlying control beliefs, participants identified similar barriers for both vehicle types, including; high costs, lack of trust, lack of control over the vehicle, lack of current legislation to support the mainstream introduction of these vehicles, and concerns of safety for self and for other road users when operating AVs. Overall, these findings provide some support for applying the TPB to understand drivers’ intended use of AVs. However, while the current study showed that the constructs of attitudes and subjective norms might reflect intended use of AVs, more research is required to further examine the role of PBC. Additionally, the findings provide initial insights into the underlying behavioural and control beliefs that may motivate drivers to use AVs and highlight the similarities and differences in drivers’ perceptions towards two levels of vehicle automation.     

To share or not to share: A theoretically guided investigation of factors predicting intentions to use fully automated shared passenger shuttles

This study applied the Theory of Planned Behaviour (TPB) to assess individuals’ intentions to use fully automated shared passenger shuttles when they become publicly available. In addition, perceived trust was assessed to examine the extent to which this variable could account for additional variance in intentions above the TPB constructs of attitudes, subjective norms, and perceived behavioural control (PBC). Further, and also guided by the TPB, the study explored the differences in behavioural, normative, and control beliefs between individuals who reported high intentions to use automated passenger shuttles in the future (high intenders) and individuals who reported low intentions to use fully automated shared passenger shuttles in the future (low intenders). Participants (N = 438; 64% female) aged between 17 and 84 years (Mage = 35.42 years) were asked to complete an online questionnaire which took approximately 15 min. The findings revealed that attitudes, subjective norms, and PBC were significant positive predictors of intentions to use fully automated shared passenger shuttles when they become publicly available. When perceived trust was added to the hierarchical regression, this variable was shown to account for additional significant variance in intentions above the TPB constructs and was shown to be a significant positive predictor of intentions. Further, the results revealed significant differences in beliefs held by high and low intenders. Specifically, high intenders held significantly more positive beliefs towards fully automated shared passenger shuttles than low intenders. In turn, low intenders held significantly more negative beliefs towards these vehicles than high intenders. Overall, these findings provide support for the utility of the TPB in examining individuals’ intentions to use fully automated shared passenger shuttles when they become publicly available.     

Predicting pedestrians’ intention to cross the road in front of automated vehicles in risky situations

Due to the absence of a human driver, the introduction of fully automated vehicles (FAVs) may bring new safety challenges to the traffic system, especially when FAVs interact with vulnerable road users such as pedestrians. To ensure safer interactions between pedestrians and FAVs, this questionnaire-based study aims to understand Australian pedestrians’ intention to engage in risky road-crossing behaviors when they interact with FAVs vs. human-driven vehicles (HDVs). A 2 × 2 between-subject design was utilized, in which two risky road-crossing scenarios were designed and took into account the vehicle type (FAV vs. HDV) and vehicle speed (30 km/h vs. 50 km/h). A total of 493 participants (aged 18–77) were randomly assigned to one of the four experimental conditions and completed an online questionnaire based on the extended Theory of Planned Behavior (TPB). This questionnaire measured pedestrians’ intentions to cross the road in the assigned scenarios as well as the motivational factors behind these intentions in terms of attitude, subjective norm, perceived behavioral control, perceived risk and trust in the vehicle. The results show that pedestrians had significantly higher intentions to cross the road in front of approaching FAVs than HDVs. Participants also reported a lower risk perception of crossing in front of FAVs and greater trust in this type of vehicle. Attitude, subjective norm, and perceived behavioral control were significant predictors of intentions to engage in risky road-crossing behavior. Findings of this study provide important implications for the development and implementation of FAVs in the future road transport system.     

Feel good now or regret it later? The respective roles of affective attitudes and anticipated affective reactions for explaining health‐promoting and health risk behavioral intentions

Evidence supporting the incorporation of affective constructs, such as affective attitudes and anticipated regret, into theoretical models of health behavior has been mounting in recent years; however, the role of positive anticipated affective reactions (e.g., pride) has been largely unexplored. The purpose of the present investigation was to assess how affective attitudes and anticipated affective reactions (both pride and regret for performing a behavior or not) may provide distinct utility for understanding intentions to perform health‐promoting and health risk behaviors over and above cognitive attitudes and other established theoretical constructs from the theory of planned behavior (TPB). Participants (N = 210) were recruited via Amazon’s Mechanical Turk to complete a one‐time online battery assessing TPB and affective constructs. Self‐reported intentions served as the main outcome measure, and hierarchical linear modeling was used to examine the effects of TPB and affective constructs across behaviors. Controlling for TPB constructs, more positive affective attitudes and greater anticipated regret, but not anticipated pride, predicted intentions to engage in future health behaviors. Anticipated affective reactions contributed explanatory variance for intentions to perform health risk behaviors, but anticipated pride and regret were not associated with intentions to perform health risk behaviors. Contributions made via the inclusion of both positively and negatively valence anticipated affective reactions for both action and inaction (performing a behavior or not) across a range of health promoting and health risk behaviors are discussed, as well as implications for future intervention work.     

Me, My Mobile, and I: The Role of Self- and Prototypical Identity Influences in the Prediction of Mobile Phone Behavior

This study examined the effect of and relationship between self- and prototypical identity influences on high-level mobile phone use from a theory of planned behavior (TPB) perspective. Participants were 252 university students who completed 2 questionnaires, 1 week apart. The first questionnaire assessed the standard TPB constructs (attitude, subjective norm, perceived behavioral control), as well as self- and prototypical identity influences. The second questionnaire assessed level of mobile phone use in the previous week. Support was found for the TPB in predicting high-level mobile use intentions and behavior. Self-identity and prototype similarity, but not prototype favorability, also significantly predicted intentions. The effects of prototype similarity on intentions were mediated via self-identity processes.     

On-Road vehicle study of the experience of automated driving

Prior studies of automated driving have focused on drivers’ evaluations of advanced driving assistance systems and their knowledge of the technology. An on-road experiment with novice drivers who had never used automated systems was conducted to examine the effects of the automation on the driving experience. Participants drove a Tesla Model 3 sedan with level 2 automation engaged or not engaged on a 4-lane interstate freeway. They reported that driving was more enjoyable and less stressful during automated driving than manual driving. They also indicated that they were less anxious and nervous, and able to relax more with the automation. Their intentions to use and purchase automated systems in the future were correlated with the favorableness of their automated driving experiences. The positive experiences of the first-time users suggest that consumers may not need a great deal of persuading to develop an appreciation for partially automated vehicles.     

Application of the Theory of Planned Behavior to Recidivism: The Role of Personal Norm in Predicting Behavioral Intentions of Re‐Offending1

The study is a partial application of the theory of planned behavior (TPB) to the prediction of young offenders’ behavioral intentions to re‐offend. Participants were 152 young offenders who were randomly selected and who completed a self‐report questionnaire assessing the sociocognitive determinants of the TPB and personal norm. It was found that attitudes and perceived behavioral control are necessary factors for the prediction of intentions to re‐offend; while personal norm contributed significantly, yet marginally. The TPB provides a parsimonious way to predict behavioral intentions to re‐offend. Personal norm could be a variable that expands the model when it is applied to the prediction of young offenders’ behavioral intentions to re‐offend.     

The importance of subjective norms for people who care what others think of them

Using the framework of the Theory of Planned Behaviour (TPB), this study examined whether the extent to which people are concerned with others’ approval of them moderates the subjective norms–intentions relationship in the context of exercise. The participants were 325 undergraduate students who completed a questionnaire assessing the TPB constructs (subjective norms, attitudes, perceived behavioural control, intentions) and the Brief Fear of Negative Evaluation Scale. The results of hierarchical regression analyses indicated that subjective norms were a significant predictor of intentions to exercise only for people highly concerned with receiving disapproval from others (i.e., high fear of negative evaluation) and not for people low on this trait.     

Investigating the motivational factors influencing drivers intentions to unsafe driving behaviours: Speeding and overtaking violations

Achieving road safety depends on driver attitudes and behaviours in handling the vehicle on roads. The availability of good road, improvement of vehicle designs and drivers experience lead to reduction in crashes but not prevention of crashes. The study aims to predict the drivers’ intentions towards speeding and overtaking violations when under the influence of motivational factors using belief measure of TPB and DBQ variables. To achieve this, questionnaires were randomly administered to a sample of Ghanaian drivers (N = 354) who held valid driving licenses. This study applied regression techniques. The result shows that the components of TPB and DBQ variables were able to predict drivers’ intentions towards speeding and overtaking violations. The study further shows that components of TPB made larger contributions to the prediction of divers’ intentions to speeding and overtaking than the DBQ. Further analysis revealed that, in the prediction of drivers’ intentions, speeding attitude was the most frequent violations compared to overtaking. The drivers tend to involved in overtaking violations when they perceived the driving motivations would enhance the performance of the behaviour. Additionally, control belief has been the strongest predictor of drivers’ intentions under the influence of motivations to speeding and overtaking violations. It appeared that the drivers who intended to involve in speeding and overtaking violations had strong beliefs in the factors and are more likely to violate based on their beliefs. The practical implications of the findings for the development of interventions to promote road safety and positive changes are also discussed.     

To Be a Donor or Not to Be? Applying an Extended Theory of Planned Behavior to Predict Posthumous Organ Donation Intentions

Using a theory of planned behavior (TPB) perspective, individual intentions to register and discuss the decision of organ donation with significant others were examined. In addition to standard TPB variables (attitude, subjective norm, and perceived behavioral control [PBC]), self-identity and moral norm were incorporated into the TPB as predictors. Australian university students ( N  = 303) completed a survey comprising standard and additional TPB constructs. Separate analyses were conducted for both registered and nonregistered participants. In general, results provide support for the extended TPB model in predicting intentions to register and discuss the donation decision, with the exceptions that self-identity did not predict discussion intentions for either registered or nonregistered participants, and PBC did not predict discussion intentions for nonregistered participants.     

Using the Theory of Planned Behavior to Predict Intention to Use Condoms Among Male and Female Injecting Drug Users

This study tested the utility of the theory of planned behavior (TPB) for understanding and predicting condom use intentions among male and female injecting drug users (IDUs). Interviews were conducted with 405 male and 315 female sexually active IDUs. Participants indicated their intentions to use condoms with main and nonmain sexual partners as well as attitudes, social norms, partner norms, and perceived behavioral control relevant to condom use with each partner type. The TPB accounted for 36 to 48% of the variance in intentions to use condoms. Intentions were related to attitudes, regardless of partner type. Partner norms were related to intentions to use condoms with main partners (men and women) and nonmain partners (men only). Social norms did not predict intentions, regardless of partner type. Perceived behavioral control was related to intentions to use condoms with main partners (men and women) and nonmain partners (women only). The findings are interpreted in light of the roles of cooperation, intimacy, and concern about self-protection.     

Personality,motivational, and social cognition predictors of leisure-time physical activity

ObjectiveThe purpose of the present study was to investigate associations between personality traits of extraversion and neuroticism, autonomous motivation, and the Theory of Planned Behavior (TPB) constructs and leisure-time physical activity. The study examined whether autonomous motivation and the TPB constructs mediate the association between personality traits and physical activity, and whether personality traits moderate the relationship of autonomous motivation and the TPB constructs with physical activity.MethodsMiddle-aged women (N = 441) completed self-report measures of personality traits, autonomous motivation, attitudes, subjective norms, perceived behavioral control (PBC) and intention. Moderate-to-vigorous leisure-time physical activity (MVPA) was measured using accelerometers approximately seven weeks later. Participants’ past accelerometer-based MVPA was available from four years earlier.ResultsOnly autonomous motivation and past MVPA directly predicted MVPA. Neuroticism and past MVPA were indirectly related with MVPA through autonomous motivation. No support for a moderator role of personality traits was found.ConclusionsCurrent data suggest that autonomous motivation and past experience are prominent determinants of accelerometer-based leisure-time MVPA, but not beliefs and intentions.     

The effect of self‐identity alongside perceived importance within the theory of planned behaviour

Self‐identity often predicts behavioural intentions after standard theory of planned behaviour (TPB) components are accounted for. However, it has been claimed this is due to conceptual similarity between self‐identity and perceived importance of the behaviour. We examined this claim within the context of recycling food waste. Participants (N = 113) completed questionnaires assessing intentions, attitude, perceived behavioural control, perceived norms, perceived importance, self‐identity, and past behaviour. Confirmatory factor analysis indicated that self‐identity and perceived importance were distinct constructs. Further, after accounting for TPB components and perceived importance, self‐identity explained a significant amount of additional variance in intentions. The present findings therefore do not support this particular argument against the predictive utility of self‐identity.     

Antecedent variables of intentions to use an autonomous shuttle: Moving beyond TAM and TPB?

IntroductionThe use of autonomous shuttles (AS) seems a promising mobility solution. Technology acceptance model (TAM) and theory of planned behavior (TPB) provide useful a priori frameworks to study AS’ acceptance, but they might arguably benefit from a specific, AS-related adjustment.ObjectiveTo provide a preliminary model of AS’ acceptance based on both laboratory and field data.MethodUndergraduate students (n = 370, study 1) and both the potential and the real AS users (n = 162, study 2) answered surveys concerned with the key TAM, TPB and evidence-based additional variables.ResultsSome of TAM and TPB constructs accounted for 40% of intentions to use an AS while further 13 to 16% were explained systematically by such variables as group norms, affective attitudes and first AS experience.ConclusionSome of TAM and TPB constructs capture substantial proportion of AS’ acceptance while additional social, motivational and experience-related factors should be taken into account.     

Distracted pedestrians in crosswalks: An application of the Theory of Planned Behavior

Thousands of adult pedestrians are killed or injured each year. In spite of ever growing knowledge of correlates of risk pedestrian behavior, much remains to be learned. A small body of research has applied the Theory of Planned Behavior (TPB) to the problem of risky crossing decisions. We employed TPB to examination of intentions to cross under varying types of distraction. Eighty adults completed measures of injury exposure, followed by a questionnaire structured around TPB assessing intentions to cross streets under common conditions of self-imposed distraction. Results were similar to other research, suggesting attitude and perceived behavioral control predicted intentions to cross streets while distracted. Results are discussed in the context of similar studies, and with regard to future directions and injury prevention efforts.     

A test of theory of planned behavior in Korea: participation in alcohol-related social gatherings

Two studies are reported using the theory of planned behavior (TPB) to predict and explain joining and not joining alcohol-related social gatherings among Korean undergraduates in various engineering majors. Specifically, considering that the attitudinal component of TPB is behavioral-outcome-based, the current study investigated whether the outcomes of engaging in a behavior and of not engaging in a behavior would similarly predict intentions to engage in a behavior and intentions to not engage in a behavior. The current study also examined whether intentions to engage and intentions to not engage would be significantly related to self-reported behavior a week later. Participants in Study 1 reported TPB components (attitudes toward behavior, subjective norms, perceived behavioral control, and behavioral intentions) concerning joining alcohol-related social gatherings. Participants in Study 2 reported TPB components concerning not joining alcohol-related social gatherings. Additionally, a week later, the participants in both studies reported their participation in alcohol-related social gatherings from the past week. Generally, the results showed that the TPB components were significantly associated with undergraduates' intentions to join and intentions to not join. Specifically, conversation-related attitudes and senior-junior relationship-related attitudes were significantly related to intentions to join, and only group-related attitudes were significantly related to intentions to not join. Intentions to join and intentions to not join were not significantly related to self-reported behavior of joining alcohol-related social gatherings a week later. The findings from the current research provide some evidence that joining or not joining alcohol-related social gatherings may not be mere behavioral opposites, predictable by the presence or absence of the same behavioral outcomes. These two aspects of the behavior may require assessment of different behavioral outcomes or different assessments of the same behavioral outcomes.     

Does it matter whether friends,parents, or peers drink walk? Identifying which normative influences predict young pedestrian’s decisions to walk while intoxicated

Drink walking, that is walking in a public place while intoxicated, is associated with increased risk of injury and fatality. Young people and males are especially prone to engaging in this behaviour, yet little is known about the factors associated with individual’s decisions to drink walk. The present research explores the role of different normative influences (friendship group norm, parent group norm, university peer group norm) and perceived risk, within an extended theory of planned behaviour (TPB) framework, in predicting young people’s self-reported drink walking intentions. One hundred and eighteen young people (aged 17–25 years) completed a survey including sociodemographic measures and extended TPB measures related to drink walking. Overall the extended TPB explained 72.8% of the variance in young people’s intentions to drink walk in the next six months with attitude, perceived behavioural control, friendship group norm, and gender (male) emerging as significant predictors. Males, as compared with females, had higher intentions to drink walk and lower perceptions of risk regarding drink walking. Together, these findings provide a clearer indication of the salient normative influences and gender differences in young pedestrian’s decisions to walk while intoxicated. Such findings can be used to inform future interventions designed to reduce injuries and fatalities associated with drink walking.     

The determinants of Portuguese preference for vehicle automation: A descriptive and explanatory study

During the last century, innovation of automated vehicles (AVs) technologies are successively maturing while progressively excluding the human intervention in vehicle driving. The objective of this paper was to analyze the determinants of Portuguese drivers’ decision to adopt AVs technologies, in an under explored context, where the driver of contemporary vehicles does all or part of the dynamic driving task (DDT) in comparison to vehicles equipped with Automated Driving systems (ADS) where the driver can become a passenger temporarily or permanently. In addition, willingness-to-pay for ADS estimates were also investigated. This study data was collected through a survey designed and deployed in Portugal. A mixed logit model was estimated, and the results obtained are in line with the literature of AVs in a number of determinants, but also highlights differences that can be explained by the Portuguese cultural, social and economic context. Overall, 83.7% of the Portuguese drivers favor contemporary vehicles, today, and among those who prefer vehicles with ADS, highly educated drivers’ are willing to pay, on average, 65,671 € for Conditional AVs, 31,185 € for Highly AVs, and about 28,622 € for Full AVs.     

Consumer knowledge and acceptance of advanced driver assistance systems

This research aimed to examine how personal car users are informed about Advanced Driver Assistance Systems (ADAS) in Australia, and the extent to which information received at point of sale influenced the level of understanding and adaptation of ADAS. Further, this study applied the Technology Acceptance Model (TAM) to assess drivers’ intentions to use ADAS within the next month. Participants were required to have purchased a new or second-hand vehicle within the past five years and which had at least one of the following five ADAS: autonomous emergency braking, lane departure warning, adaptive cruise control, blind spot monitoring, and rear cross traffic alert. Participants (N = 217, Mage = 47.87 years, 149 male) completed a 20-minute online questionnaire. The findings revealed that 122 (56%) participants reported not seeking out any information about ADAS prior to purchasing their vehicle. Further, the most reported approaches used by participants to learn about their vehicle’s ADAS were through the owner’s manual (n = 121, 55%) and via trial and error (n = 117, 54%). It was also found that total time spent with the salesperson in explaining ADAS features did not influence drivers’ level of understanding of ADAS or number of days to adapt to the ADAS in their vehicle. However, and consistent with the TAM, perceived usefulness and perceived ease of use were significant positive predictors of intentions to use ADAS within the next month. It was also found that participants who learnt about these technologies either via reading the owner’s manual, trial and error, or a verbal explanation at point of sale appeared to be more frequently classified as reporting higher acceptance of ADAS than those participants who did not use those learning methods. Given that technology in vehicles will continue to advance, it is vital that more work is conducted to educate drivers about the functionality of ADAS. Further, it is also important to communicate where buyers of personal cars can go and find accurate and reliable information about ADAS.