1. Introduction
Continuous urbanisation brings with it the need for different forms of transportation for commuting. Globally, the primary method of commuting is private transportation [
1,
2]. Even though private transportation is not a sustainable mode of transport, it offers comfort, convenience, time efficiency, reliability, privacy, and flexibility [
3,
4]. The reliance on private transit has resulted in a rapid increase in the rate of motorisation in developed and developing countries. The statistics in Malaysia showed that the number of registered vehicles increased by about 66.2% within a decade (2008 to 2017) [
5].
One of the downsides of the advancement in motorisation is the high number of severe traffic-related injuries. The evidence provided by Ojo [
6] showed that the road traffic deaths and injuries in developing countries might be up to 80% higher between 2000 to 2020 due to the rapid increase in motorisation and the higher the number of vehicles per inhabitant. The statistics for Malaysia showed that in 2017, 802,532 road traffic accidents resulted in 16,589 injuries and 6740 deaths [
5]. Most of the accidents involved young drivers between 16–25 years old (29.5%). Of the total number of road crashes, motorcycles were involved in 564,491 cases, followed by cars, which were involved in 108,221 cases [
5]. According to Borhan et al. [
7] and Dapilah et al. [
8], globally, the number of deaths because of road crashes is about 3000 each day or 2 million annually, thus making road crashes a serious public health problem that threatens today’s society [
9]. The world has been focussing on preventing the injuries, disabilities, and deaths caused by traffic accidents, and researchers and transportation engineers are trying to find ways to reduce accident-related injuries and fatalities, and thus enhance sustainable traffic safety [
10,
11,
12].
Among the proposed method for reducing the number of accident-related deaths, the most effective measure is encouraging seat belt use to reinforce sustainable driver behaviour. This measure focusses on vehicle safety measures to reduce the risk of fatality and enhance sustainable traffic safety [
13,
14,
15,
16,
17]. Demirer et al. [
18] and Hezaveh and Cherry [
19] have shown that proper seat belt use reduces the risk of fatalities among road users between 44% to 73%. Despite the apparent benefits of seat belt use, several issues must be resolved [
20,
21,
22,
23]. The rate of seat belt use is the lowest among young road users relative to other age groups [
24]. According to Kim et al. [
15] and Shults et al. [
21], most road crashes involve young adults because they are unlikely to use seat belts. Therefore there is an urgent need to deal with this problem. The reluctance of young adults to use seat belts shows that even though society is aware of the significance of sustainable traffic safety, most of them exhibit limited structural behaviour towards traffic safety sustainability. This attitude is similar to the findings made by Langley and Broek [
25] that people ignore environmental sustainability even though they have a positive attitude towards the idea of sustainability.
This crucial issue has attracted the attention of researchers of traffic safety. Begg and Langley [
26] investigated the demographic factors of drivers and how these factors contribute to causing road crashes, reckless driving, and thrill-seeking culture in New Zealand. The researchers used the demographic factors to determine the reason for the reluctance of drivers to use seat belts, and the results showed that young adults did not use seat belts because they were lazy or forgetful, felt uncomfortable, or perceived low risk of injury. A study in the state of Missouri, U.S., discovered that seat belt use is dependent on several factors such as the demographic characteristics of high school students, type of vehicle, type of school, and location of the school [
15]. According to Shults et al. [
21], individual characteristics such as age, gender, race, and environmental factors influenced the use of seat belts by young adults. Goldzweig et al. [
24], Mccartt and Shabanova [
27], and Wan Ahmad Kamal et al. [
28] discussed the issues related to young adults and their attitude towards using seat belts.
Instead of investigating socio-demographic factors to predict the determinants of seat belt use, several researchers considered the socio-psychology of an individual to determine the factors influencing the intention to use seat belts. For instance, Şimşekoğlu and Lajunen [
29] and Ali et al. [
30] proposed a model based on the theory of planned behaviour (TPB) to explain the factors influencing the intention of seat belt use in Turkey and Iran, respectively. The model showed a good fit in explaining the self-reported seat belt use by front-seat passengers (students) in Turkey [
29] and among car drivers in Iran [
30] compared to the health belief model (HBM). Okamura et al. [
31] proposed a model for predicting the factors influencing the non-use of seat belts by front-seat passengers in Japan. Okamura’s model indicates that the intention of seat belt use is influenced by self-efficacy, individual attitude, descriptive norms, and experience of being ticketed for non-use of seat beats. Other models have been used to investigate the intention of seat belt use in different regions of the world [
6,
16,
21]. Even though there are many proposed models for seat belt use, the factors used as the foundation of each model focussed on different variables, such as both the drivers and passengers, drivers, passengers, non-use of seat belts by drivers, and region. Therefore, the models should be applied to other populations and countries with caution because different societies and countries have different cultures [
7,
32].
Given the limitations of previous studies, a specific model is needed to explore the factors influencing the intention of young Malaysian drivers to use seat belts. The authors believed that there was a dearth of studies on the sustainable behaviour of young Malaysian drivers in terms of the intention to use a seat belt. Previous studies focussed on determining the factors influencing seat belt use from a general perspective but did not perform an in-depth analysis of the factors influencing the intention of young drivers to use seat belts. There is, therefore, a gap in understanding the behaviour of an individual in the effort to encourage the use of seat belts by young adults because road users’ sustainable behaviour is one of the most influential factors relative to the other intentions they may have [
7].
This study seeks to bridge the gap and investigate the factors influencing the sustainable behavioural intentions of young Malaysian drivers to use seat belts by extending the TPB to include habit as a new construct. The remainder of this paper is structured as follows:
Section 2 discusses the literature review and hypothesis development.
Section 3 describes the research methodology, and
Section 4 presents the results of the study. Finally,
Section 5 presents the discussion and conclusion of the study.
3. Research Methodology
Results of a survey were used to investigate the link between habits, driver attitude, subjective norms, and perceived behavioural control in predicting the factors influencing the intention of young Malaysian drivers to use seat belts.
Appendix A presents the questionnaire, which contains all the constructs in the proposed paradigm of the framework. The questionnaire was adapted from the studies in the literature review (see
Table 1). The items were modified to suit the cultural, economic, and social context of Malaysia to test the viability of the hypotheses and framework. The questionnaire comprises two sections. The first section contains four items and gathers the respondents’ demographic data, namely, age, gender, employment status, and education background. All items in this section were evaluated using a categorical scale. The second section examines the five concepts in
Appendix A. The items were then measured using a five-point Likert scale, ranging from 1 = Strongly disagree to 5 = Strongly agree. The highest scores indicate the highest the level of interest of a specific measure. These items were validated by three professors who were domain experts. A pilot test was carried out to identify the weaknesses (errors or mistakes) in the designed instrument and make the necessary modifications before implementing them in the actual study [
1]. The pilot test involved 50 randomly selected students who drove on the Universiti Kebangsaan Malaysia campus. The feedback obtained from the pilot test showed some items in the questionnaire needed modification to improve clarity and consistency.
Table 1 presents the result of the reliability analysis of the pilot tests.
Selangor was selected as the study location because it had the highest number of road crashes (154,958 cases) and deaths (1087 cases) in 2017 [
5]. The full-scale survey was carried out between 12 October 2018 and 22 December 2018. Three enumerators gathered the data in areas including Serdang, Kajang dan Shah Alam because these areas have a large population of young university students who would most likely be willing to participate in this study. The data was gathered from 480 respondents using the convenience sampling technique. The respondents were between 18 and 25 years old, had a valid driving license, had driven during the past month, and were willing to participate in the survey.
The enumerators explained the objective of this study to the respondents before beginning the survey, as this would increase the response rate and accuracy of the gathered data [
42,
61]. A total of 398 questionnaires were analysed after eliminating the invalid and incomplete responses (response rate of 83%).
Table 2 presents a summary of the respondents’ profiles. The data were analysed using the Statistical Package for Social Sciences Software (SPSS) version 21 and Analysis of Moment Structure (AMOS) version 21. This study developed a structural equation model based on the covariance-based estimator. The systematic procedure for data analysis included exploratory factor analysis, assessment of the measurement model, and assessment of the structural model.
5. Discussion and Conclusions
This research extended the TPB to include a measure of habit to determine the factors that enhance the sustainable behavioural intention of seat belt use among young Malaysian drivers. Covariance-based structural equation modelling (CB-SEM) was employed to investigate the connection between attitude, subjective norms, perceived behavioural control, and habit with the behavioural intention of young drivers to use seat belts. Many researchers used TPB in their studies on seat belt use [
29,
30,
31,
73], but very few used SEM and the extended version of the TPB.
Hence, the present study was a novel approach for understanding the intention of young Malaysian drivers to use seat belts by using the extended version of TPB and CB-SEM models. This study is significant because it sought to understand the relationship between constructs and their impact (behavioural intention) on young drivers’ intention to use seat belts in the future. The authorities and policymakers can use the findings of this study to understand the determinants of young drivers’ intentions to use seat belts and introduce preventive measures to deal with the low rate of seat belt use among young Malaysian drivers. The suggested paradigm of the framework comprised attitude (54%), subjective norms (37%), and behavioural control (58%), which explained 76% of the variables for drivers’ seat belt intention. Three TPB constructs, attitude, subjective norms, and perceived behavioural control, had a significant positive impact on young Malaysian drivers’ intention to use seat belts.
Perceived behavioural control was the most significant predictor of seat belt use among young Malaysian drivers, followed by attitude and subjective norms. This finding is consistent with the results obtained by Ali et al. [
30] that attitude, subjective norms, and perceived behavioural constructs are the critical determining factor of Iranians’ intention to use seat belts, with a variance of 39%. Other studies on seat belt use and traffic safety reported similar results [
31,
45,
73,
74,
75], which provide unequivocal support for the results of this research. However, the findings of this study differ from the results obtained by and Şimşekoğlu and Lajunen [
29], which showed that only attitude and subjective norms influenced drivers’ intentions to use seat belts when driving on rural and urban roads in Turkey. Şimşekoğlu and Lajunen [
29] also reported that perceived behavioural control was not a critical factor in the behavioural intention of drivers.
The attitude of drivers influences their intention to use seat belts, especially when it is associated with benefits such as comfort and time-saving. Young drivers were the least likely to use seat belts compared to other age groups [
21,
27], which is in line with the findings made by Borhan et al. [
7] that young adults had a greater tendency to take risks on the road. On the other hand, subjective norms indicated that young drivers were influenced by social referents such as parents, friends, and spouses.
Young drivers are more likely to perform a behaviour that is approved by social referents. According to Zhou et al. [
47], humans learn by observing the behaviour of others and imitating the action without thinking. In the case of this study, young drivers observed social referents obeying traffic rules by wearing seat belts and imitated the behaviour. Thus, subjective norms can influence the behaviour of young drivers and contribute to enhancing a sustainable society. Besides, perceived behavioural control is intended to assess the ability of an individual to perform a particular behaviour. Ali et al. [
30] posited that if young drivers had a better sense of control over the use of seat belts, they would be more likely to use seat belts in a specific circumstance.
This study used an extended TPB through the habit construct to understand the use of seat belts among young drivers. The habit construct had an indirect positive influence on behavioural intention through attitude and perceived behavioural control. Previous studies [
29,
59] showed that one of the reasons the Turks fasten their seat belts when driving is because of habit. Forward [
74] stated that habit contributes to the non-use of seat belts when driving. Thus, this study proposed several measures to enhance the intention of young drivers in Malaysia, or even throughout the globe, to use seat belts.
The most effective measure to improve sustainable traffic safety is enforcing seat belt laws [
21,
76,
77,
78]. Curtis et al. [
77] showed that enforcement of seat belt laws increased the use of seat belts by 17–26%. The primary seat belt law allows the police to stop drivers who do not use seat belts. The secondary seat belt law gives the police the power to issue tickets to unrestrained drivers who are pulled over for violating other regulations. Enforcing the primary seat belt law is more effective in increasing the use of seat belts, especially by teenage drivers [
21]. Salzberg and Moffat [
79] reported that the primary seat belt law was critical in increasing the rate of seat belt use in the state of Washington. Many previous works [
9,
76,
78] suggested increasing the statutory fine to ensure the use of seat belts by drivers. In summary, strict enforcement of seat belt laws and fining the drivers, especially young drivers, who violate the law would encourage them to use seat belts and achieve sustainable traffic safety.
This study identified the critical role of attitude, subjective norms, perceived behavioural control, and habit in enhancing the intention of young drivers to use seat belts. Government agencies have to formulate better strategies and allocate more resources to influence young drivers’ perspectives on the use of seat belts to ensure safety. There is a need to change the attitude of young drivers towards seat belt use and encourage them to practice sustainable driving behaviour. One of the most effective ways to change behavioural intention and ensure the sustainable development of society is through campaigns. The campaigns should inform and reinforce a positive attitude towards the use of seat belts by young drivers. According to Akba et al. [
10] and Şimşekoğlu and Lajunen [
29], campaigns that focus on the benefits of using seat belts are more effective than those that highlight the adverse effect of not using seat belts. Borhan et al. [
42] recommended conducting the campaigns through mass media, such as social networking sites, newspapers, and television, as it can reach a large segment of the population. Similarly, Langley and Broek [
25] reported the benefits of using social media to improve the sustainable behaviour of society.
Previous studies have proven the effectiveness of a mass media campaign on road safety in positively influencing the behavioural intention of drivers towards sustainable traffic safety [
80,
81,
82]. Another way to change the public’s perception of seat belt use is by informing them through mass media that the proper use of seat belts will reduce or prevent serious injuries or fatalities in road accidents. The campaigns should not be limited to young drivers but also target important social referents such as parents, spouses, and friends, as young drivers tend to emulate them. This effort is consistent with the outcomes of this study in that subjective norms are a strong determiner of young drivers’ intentions to use seat belts. There is also a need to educate schoolchildren on the importance of using seat belts and practising correct social norms [
47]. Providing early education would put them on the right path to make it a habit to use seat belts.
The effort to change the behaviour of road users must not depend only on campaigns and safety education. Engineering countermeasures can also help change the behaviour of young road users. Cunill et al. [
9] believed that improving the design of seat belts to make them more comfortable could increase the use of seat belts. Kulanthayan et al. [
78] and Şimşekoğlu and Lajunen [
59] reported that discomfort was one of the main reasons drivers were reluctant to use seat belts. In addition, advanced vehicle technology such as a seat belt interlock system and seat belt reminder system could increase the use of seat belts. The seat belt interlock system requires the driver and front-seat passenger to fasten the seat belts before the engine can be started. Kidd and Singer [
13] pointed out that the seat belt interlock system is more effective in increasing the use of seat belts compared to the reminder system. Unfortunately, this system is not well-received by the users.
In conclusion, proper seat belt use by young drivers reduces the injuries and risk of death due to road accidents. The effort to encourage young Malaysian drivers to use seat belts must focus on the drivers’ behavioural intention. This study used an extended TPB model with a new construct (habit) to make a better prediction of young Malaysian drivers’ intention to use seat belts and thus achieve sustainable traffic safety. The model used in this study effectively reinforced and substantiated most of the hypotheses. The outcomes of the present study can serve as the basis for intervention measures that can enhance the sustainable seat belt use behaviour of young drivers and eventually reduce the severe injuries and risk of death due to road crashes.