Work-Related Driving of Heavy Goods Vehicles: Factors That Inﬂuence Road Safety and the Development of a Framework for Safety Training

: Road trafﬁc accidents are a major health concern all over the world. Each year, 1.3 million people die in fatal road trafﬁc accidents. Fatal and serious heavy goods vehicle (HGV) crashes are over-represented in many countries. This paper is a contribution to the road safety literature and has two aims. First, the study seeks to identify important factors in managing road safety for work-related driving of HGVs. Second, the study proposes an overall framework for how safety training could be executed and its overall content. Methods used were a literature review and a case study. The results show that important factors for management of road safety could be arranged at different levels: governmental level, third-party level, organizational level and driver level. Most important is that a systematic approach to road trafﬁc safety for HGVs is essential. Every party is jointly responsible for road trafﬁc safety, and parties must communicate and work together to increase road trafﬁc safety for work-related driving of HGVs. By developing a safety training program for all parties in the system, the study proposes a method for increased communication, collaboration and cooperation between parties. companies. The study has four aims: (1) to map the safety structure at the different levels of the safety ladder, (2) examine whether safety culture is improved with increased structural measures at each safety ladder level, (3) examine whether the accident risk decreases at each safety ladder level and (4) discuss practical implications. Based on interview results, increasing structural safety measures for the companies at each level of the safety ladder are registered. Survey results indicate increasing safety culture scores at each level of the safety ladder, while the accident risk decreases. The study concludes by suggesting the concrete management practice related to each level as good practice, as these seem to be related to the increases in safety culture and decreases in accident risk. Safety commitment of managers and employees. Follow-up on driver behavior. Focus on work-related factors’ inﬂuence on trafﬁc safety. Safety management system. the of and to the Findings indicate that buyers of road transport services have an impact on both sustainability and safety in the chain of road transport, by exerting inﬂuence through pricing and delivery demands. Transport buyers must set requirements for the road transport they order, be willing to pay for safe road transport and be aware of how their delivery demands have an impact on driver behavior.


Introduction
Road traffic accidents are a major health concern all over the world. Each year, 1.3 million people die in fatal road traffic accidents [1]. Another 20-30 million people sustain non-fatal injuries annually [2]. Fatal and serious heavy goods vehicle (HGV) crashes are over-represented in many countries [3]. Due to HGVs' great size and weight, accidents involving these vehicles are often fatal. In Norway, road transport organizations employ a large number of professionals whose main work is on the roads. HGV drivers account for the largest proportion (40%) of drivers in work who are involved in accidents and sustain injuries [4]. In Norway, specific interventions and measures directed particularly at work-related driving of HGVs are implemented. If new interventions and measures are not put in place, however, reducing HGV accidents and consequently achieving Norway's road safety target presents a challenge [5].
Even though there is a large body of research on the causes of HGV crashes, there is little research to evaluate the strategies that might be effective for preventing these crashes [3]. As a consequence, new research focuses increasingly on a systematic approach to reducing accidents involving HGVs. This means that accidents that do occur are not solely the driver's responsibility [5]. A crash caused by fatigue, for example, might not solely be the driver's fault, but could also be due to the supervisor's lack of involvement in route planning, or the type of compensation method used to align performance objectives with drivers' payment. Supervisors' level of involvement may also be restricted due to their own workload, company policies or pressure from higher up in the organization [6]. Recent research highlights stress-and fatigue-management policies and interventions in order to reduce work-related accidents with HGVs [7]. Hence, several small decisions from the top level down to the driver level may have triggered the actual accident. This paper is a contribution to the road safety literature and has two aims. First, the study seeks to identify the important factors in managing road traffic safety for work-related driving of HGVs. By conducting a literature review, an overview of what the research literature deems to be important factors will be presented. The literature review has a focus on the management perspective and does not cover legal nor other perspectives.
Safety training and education are highlighted as important factors in managing road safety for work-related driving of HGVs [3,8,9]. In a recent study by Llamazares, J., S. A. Useche, L. Montoro and F. Alonso [10], similarities between commuting crashes and the work environment of professional drivers are suggested. It is stated that time pressure and fatigue are potential enhancers of commuting accidents the same way these factors are enhancers of accidents involving professional drivers. An important finding in their study is that 44% of the commuting crashes involved drivers with less than ten years of tenure. The study therefore concludes with the importance of job experience and training as protective factors.
Even though safety training and education are highlighted as important factors, there is little research into how such training could be executed and the potential content of such training and/or education. This study's second aim is therefore to propose an overall framework for how safety training could be executed and its overall content. Safety training would thereby be directed towards all parties in the system of work-related driving of HGVs. However, most attention will be given to safety training directed at drivers, and detailed safety training is illustrated by a Norwegian case study. This leaves the study with the following two research questions: (I) What are important factors to manage road traffic safety for work-related driving of HGVs? (II) How can an overall safety training framework be arranged to enhance road safety for work-related driving of HGVs?
A presentation of the methodology and results is provided below. Thereafter, results are discussed in regards to previous literature. Finally, a conclusion is proposed.

Literature Review
This study's first question is answered by using literature review as a method. The purpose of this literature review is to identify important factors to enhance road safety for work-related driving of HGVs. The literature review was conducted according to the method described in [11]. The method differs from a systematic literature review because the method allows broader topics where many different study designs might be applicable. Additionally, the method does not address very specific research questions, nor does it assess the quality of the studies included. The main aim of the method is to map relevant literature regarding important factors to manage road safety for work-related driving of HGVs. The stages of the literature review are as follows: (1) Identifying the research question, (2) finding relevant studies, (3) selecting the studies, (4) charting and collating the data and (5) summarizing and reporting the results.
Step 1: Identifying the research question As stated in the Introduction, this paper seeks to identify research literatures which present important factors that affect the management of road traffic safety for work-related driving of HGVs. Appendix A, Table A1, provides an overview of the studies included in the review, as well as a summary of the aim of the study, main findings and which factors have been identified.
Step 2: Finding relevant studies The review was carried out according to the method described by Hart, C. [12]. The literature search was conducted in two phases. The first phase was conducted in October-December 2019 and the second phase was conducted in October-December 2021. In the first phase (October-December 2019), an extensive search was performed of eight different databases. The databases providing the most references were Google Scholar, Oria, Proquest, Science Direct, and Taylor and Francis. In addition, a second literature search phase was conducted (October-December 2021). This search was performed based on literature the researcher was familiar with and perceived as relevant to the study objective. Moreover, the search also included new research published from the years 2019-2021. The keywords used in the search were 'risk management, safety culture, transport and/or road transport'.
Step 3: Selecting the studies The initial search included studies of all transport modes, such as road, train, air and sea. Based on titles, studies that involved transport modes other than road transport and duplications were excluded. The remaining road transport studies had to present factors that could influence the management of road traffic safety for work-related driving of HGVs. Hereby, studies that take a management perspective. Other inclusion criteria (Table 1) were that the articles had been published between 2014 and 2021, were online, peer-reviewed and written in English. Step 4: Charting and collating the data Articles were then critically reviewed according to the method described by Hart, C. [12]. The following statistics were registered for each article: the study's origin, authors, year of publication, method used, aim of study, main result and HGV road safety factors identified (Appendix A).
Step 5: Summarizing and reporting the results Main findings from all included studies were organized on a chart, compared and summarized. In addition, a descriptive text about specific HGV road safety factors linked to each study was produced (Appendix A).

Case Study
This study's second question, concerning how an overall framework for safety training could be arranged to enhance road safety for work-related driving of HGVs, was answered by using the results from the literature review, as well as a small-scale case study [13].
A case study affords the researchers an in-depth understanding of the phenomena that is being studied. There are mainly three types of case studies: intrinsic, instrumental and collective case studies [14]. In this study, an instrumental case study has been used, meaning that the case study uses a particular case to study the phenomena [14]. The study was conducted according to the description in [14].
Step 1: Defining the case The case that was studied was the practical driving in periodic training of professional drivers (a more detailed description of mandatory periodic training in relation to the case study will be provided in Section 4.3) [15]. The research question that was to be answered was how an overall framework for safety training could be arranged to enhance road safety for work-related driving of HGVs.
Step 2: Selecting the case The reasoning behind the selection of the case was that the practical driving part of the periodic training of professional drivers could be an illustrative case, to develop a framework for safety training that is not too resource-demanding. Implementation of such a framework could be assumed to be easier for road transport organizations.
In addition, the case was chosen because of its accessibility for the researchers. Researchers were given access to instructors, professional drivers who attended the course, vehicles and locations.
Step 3: Collection of the data Data were collected through observation of the course at a Norwegian training center and an interview with one instructor. In addition, driver performance results were collected for the practical driving. Results extracted from these data are presented in Section 4.3.
Step 4: Analyzing, interpreting and reporting the data The data that were collected through observation and the interview were analyzed and interpreted with the research question in mind. Observation and interview notes were read and re-read to be familiar with the data. After this phase, the researchers identified important factors that could be used as a basis for the framework for safety training for work-related driving of HGVs. In addition, driver performance results were used to show improvement in driver behavior.

Results
In the following sections, the results from the literature review and the case study will be presented.

Search Results
A total of 805 studies were identified by the keywords used in the literature search and the additional manual search. However, after assessing the studies according to the inclusion criteria and removing duplicates, 93 studies were potentially relevant. The abstracts of these 93 studies were then reviewed. After this, 22 studies were included in the review ( Table 2).

Descriptive Presentation-Outcome
The analysis of the 22 included articles was conducted with the following research question in mind: What are important factors to manage road traffic safety for work-related driving of HGVs? Analysis of the articles showed that they could be categorized into three distinct groupings: articles with factors contributing to road traffic safety on an (I) organizational level, (II) driver level and (III) third-party organizations and regulatory bodies level. In the following sections, a presentation of the factors at each level is provided.

Organizational Level
There is a need for management of road transport organizations to implement a system-thinking approach and safety management systems (SMS) in road transport organizations [3,4,[16][17][18][19]. Accidents involving HGVs are likely to be a result of systems issues involving a network of interlinked contributory factors [19]. A reductionist perspective of finding the cause of an accident will not inform effective interventions or policy development [19]. Instead, the focus will be on identifying unsafe driver behavior, implying that the driver is solely to blame for the accident [7]. A collectivistic perspective is required in order to improve knowledge sharing and situational safety practices in transport [8]. Moreover, it must be acknowledged that the transport system has characteristics of a complex sociotechnical system, whereby all parties should be taken into consideration when an accident occurs [7]. A systematic approach to workplace road safety would acknowledge that responsibility for road traffic safety is shared across the system and that resources allocated to plan and manage workplace road traffic safety should be focused across all levels of the system, and not solely on the behavior and practice of the individual driver [1].
It is stated that transport organizations have little focus on organizational safety management (OSM), and thereby also little focus on SMS [4]. This is a particular challenge for small transport companies with limited resources. Consequently, an OSM strategy for small transport companies was developed in one of the studies [4]. To develop this OSM strategy, Naevestad et al. identified a set of evidence-based organizational safety measures that fulfilled five criteria. They had to: (1) address risk factors found in previous research, (2) have an effect on safety outcomes in previous research, (3) be attainable at a relatively low cost, (4) not be too complex, content-dependent or comprehensive and (5) be complementized to existing safety management standards. The measures identified on the basis of these five criteria were then arranged on a ladder, whereby the organizations start at the lowest level, before proceeding to: level (1) safety commitment of managers and employees, level (2) follow-up of driver speed, driving style and seat belt use, level (3) focus on work-related factors' influence on traffic safety (e.g., organization of transport) and level (4) safety management system (e.g., ISO 39001). It is argued that the safety culture increases at each level of the ladder, while the accident risk decreases [2].
It is stated that driver behavior is affected, among other factors, by the perceived level of stress. How transport schedule planning is conducted influences this perception (e.g., fatigue risk due to long working hours, as drivers get paid for actual production). Route planners must be aware of this risk when scheduling transport routes. The implementation of training programs for managers is highlighted as important [20][21][22][23].
The review of the literature showed some factors that stand out as important for the management of road safety for work-related driving of HGVs at an organizational level. In particular, there is a need for a systems approach and the implementation of safety management systems (SMS). It is crucial that the SMS include such elements as follow-up on driver behavior, training programs for both management and drivers and awareness about route planning, stress and fatigue. An overview of the literature is presented in Table 3. Table 3. Organizational level.

Source Findings
Newnam et al. [19] There is a need for systems-thinking for management of transport companies.
Li and Itoh [16] Mooren et al. [3] Moreen et al. [17] Naevestad et al. [18] Phillips et al. [22] Warmerdam et al. [24] Naevestad et al. [4] Naevestad et al. [2] Grinerud et al. [25] There is a need for the implementation of a safety management system (SMS) in road transport and for systematic safety management work. Effective workplace management programs must also include the drivers, who should be seen as the companies' responsibility. Implement training programs for managers of drivers.
Dawson et al. [20] Phillips et al. [22] Fatigue amongst drivers must be addressed by implementing fatigue management systems.
Thompson et al. [23] How drivers are paid affects the safety level. Payment systems should be 'flat-range' wage systems.
Li and Itoh [16] Grytnes et al. [8] Grinerud et al. [25] Increase communication between drivers and management and their willingness for teamwork.

Driver Level
At the individual driver level, several studies highlight the importance of driver/safety training and monitoring of driver behavior. This is argued to be the management of road transport organizations' responsibility: to provide their drivers with the right competence to execute their work. It is highlighted that safety training is closely linked to safety outcomes [3,4]. It is stated that such safety training could be arranged differently in terms of both informal courses/coaching/knowledge sharing, and formal training/education. The management of road transport organizations must provide an opportunity to identify and reduce the frequency of unsafe driving behavior by implementing corrective measures, such as coaching. The authors of [9] highlight the importance of a collectivist practice among drivers that can be utilized to improve knowledge sharing and situational safety practices. Li, Y. and K. Itoh [16] suggest more formal training, whereby they highlight proper safety training to give drivers more realistic views of stress/workload effects on their performance at work. Furthermore, in 2009, mandatory periodic freight transport training was implemented in Europe [15]. It is stated that after completing this periodic training, the driver/student will: (I) drive optimally and safely, (II) demonstrate professionalism in the execution of the profession and (III) protect their own and others' safety at work when the vehicle is stationary. Elvebakk, B., T.-O. Naevestad and L. C. Lahn [15] state that the periodic training is a success in many ways. This conclusion is based on Norwegian students' self-reporting that they have acquired new knowledge and changed their driving practices after completing 35 h of mandatory periodic training (a more detailed description of mandatory periodic training will be provided in relation to the case study in Section 4.3).
However, even though proper safety training is likely to have a positive outcome for road safety, few road transport organizations systematically provide non-mandatory safety training for their drivers [25]. The reasons for the lack of such programs is cost, a lack of information about efficient training programs, logistics and a lack of senior management support [26]. Nonetheless, there are also findings that suggest that by providing regulatory driver/safety training, road transport organizations have an advantage when recruiting new drivers, as many drivers perceive driver/safety training as important [25]. In addition to driver/safety training, studies also highlight the importance of follow-up on driver behavior (e.g., [4]). It is stated that technology and organizational follow-up on driver behavior are important for managing road safety with work-related driving of HGVs.
After reviewing the literature, some factors stand out as important for the management of road safety for work-related driving of HGVs at a driver level. They particularly include that drivers should have proper safety training and education in terms of driving behavior and that this behavior should be regularly followed up. An overview of the literature is presented in Table 4. Table 4. Driver level.

Third-Party Organizations and Regulatory Bodies
Different studies highlight third-party organizations and regulatory bodies as important parties that can influence safe road transport using HGVs. In this study, third-party organizations are limited to focus on buyers of road transport services. Naevestad, T.-O., R. O. Phillips and B. Elvebakk [18] state that time pressure is a critical problem in the transport industry. It is said that, for example, transport buyers and forwarding agents are likely to put pressure on/stress drivers. This means that drivers take greater risks while driving due to tight time margins for assignments [5,9,18]. Transport buyers and forwarding agents can also influence safe road transport through the requirements they set. These requirements include that drivers must have winter driving proficiency before transporting their goods on winter roads [9]. It is stated that a lack of skills to drive on Norwegian winter roads is a road safety challenge [29]. The management of road transport organizations' choice of strategy is influencing what kind of customers they acquire. Hereby, customers that enhance or decrease road traffic safety for work-related driving of HGVs [25].
Governmental and regulatory bodies are important for the management of road safety for work-related driving of heavy goods vehicles. In this study, governmental bodies are limited to be those who approve legal acts, while regulatory bodies are limited to those who enforce laws and regulations. They play a key role in maintaining safety at all levels through their regulations and policies [7]. For example, if regulatory bodies' inspections fail to detect deficiencies in road transport organizations' maintenance procedures, this may result in HGVs with non-functional brakes being allowed on the road. Further, if governmental and regulatory bodies approve and enforce laws and regulations that are not in line with actual day-to-day transportation, challenges for drivers and road transport organizations in applying these regulations will occur. To prevent these challenges, frequent communication and collaboration between parties is highlighted as important.
After reviewing the literature, some factors stand out as important for the management of road safety for work-related driving of heavy goods vehicles at a third-party organizational and regulatory body level. It is particularly important that third-party organizations and governmental and regulatory bodies increase their collaboration, so that the different parties are familiar with the challenges at different levels. An overview of the literature is presented in Table 5. Table 5. Third-party organizations and regulatory bodies.

Case Study
In the following, results collected from (1) interviewing an instructor and (2) observing actual driver training in module 5 in periodic training for professional drivers are reported.
The actual training in module 5 was conducted as shown in Table 6. Table 6. Actual driver training module 5.

What Who
Introductory conversation between instructor and driver Instructor and driver in dialogue 60 min of driving Driver active, instructor is a passive observer Feedback conversation Instructor and driver in dialogue 60 min of driving Driver active, instructor active with clues and feedback on driving behavior Feedback conversation Instructor and driver in dialogue The driving rounds of 60 min are exactly the same for both rounds. The driver is measured by explicit factors in both rounds, so that improvement can be registered. These factors are fuel consumption, speed, number of stops and time consumption. The overall aim is to drive optimally, defensively and safely, and it is proposed that these factors can serve to illustrate whether this aim is achieved or not. For example, if fuel consumption is lower in round two, this is most probably because the driving is better planned, and hence safer. Less stops in round two also indicate better planned driving and thereby more optimal and safe driving. Full stops with HGVs are time-consuming because it takes time to stop and accelerate heavy weight. Unnecessary stops increase time and slow down the overall speed. In addition, the professional instructors use their experience to assess whether the driving is optimal, defensive and safe. This includes whether speed is adjusted to the circumstances, distance to others and positioning on the road in general and in particular towards intersections or other similar situations. The results for 17 drivers (Table 7) showed a better score for almost every factor from round 1 to round 2.
An example could be Driver 17, who reduced their fuel consumption by 0.37 L, increased the average speed by 6 km/h, reduced the number of stops from 7 to 2 and reduced time consumption by 11 min. In addition, the professional instructor stated that the driving in round 2 was more optimal, defensive and safe due to the driver's improved planning of driving behavior.

Discussion
This study's first aim was to identify important factors to manage road traffic safety for work-related driving of HGVs. These factors were categorized into three groups: how management of road transport organizations' decisions could affect road traffic safety for work-related driving of HGVs on an organizational, driver and third-party level.

Important Factors to Manage Road Safety for Work-Related Driving of HGVs
The majority of the studies in the review see road traffic safety for work-related driving of HGVs as a complex phenomenon. This means that the driver is not solely to blame when a road accident involving an HGV occurs. A systematic approach to road safety for HGVs is essential. It is stated that third-parties such as governmental and regulatory bodies must develop and enforce laws and regulations in line with road transport organizations and driver challenges [6]. Other third parties such as buyers of road transport services must be made aware of their power to influence road safety and to set requirements that do not reduce safety levels [5,9]. The road transport organizations by which the drivers are contracted must facilitate good conditions for drivers. Pay and working hours must be acceptable, and it must be possible to implement routes without drivers having to break the law in terms of driving and resting times, etc. [18,27]. At the driver level, it is stated that accidents that can be related directly to unsafe driver practices are often a result of speeding, following too closely, frequent or rapid lane changes, unsafe braking and acceleration, driver distraction or inattention and failing to wear a seat belt [4,28].
The aforementioned factors should be easy to handle at each level. This means that when governments and regulators develop laws and regulations, these laws and regulations should make sense for those developing them. Road transport organizations should not face any challenges in terms of facilitating good conditions for drivers, since after all they are the ones hiring the drivers. However, a challenge for management of safety in this system is a lack of communication and collaboration between different parties in the system [1,9,27]. There is a need for parties to be aware of the challenges experienced by other parties at different levels of the system. Governments and regulators must develop laws and regulations that make sense for those who will be affected by these laws and regulations, namely road transport organizations, drivers, etc. Moreover, road transport organizations must facilitate good conditions for drivers, and the drivers must decide what good driving conditions are. As a consequence, all factors must be viewed in context, in order to manage road traffic safety for work-related driving of HGVs. Latent failure can only be detected if knowledge, competence and experience are shared between all parties in the system. Latent failures in this context refer to errors that may occur due to actions and decisions made by management or others who are removed from the direct control interface. Such latent errors could, in the next step, lead to active failures. That is where the consequences are instantly visible, and where there is a clear relationship between cause and effect [30], for example when an HGV driver is involved in a road accident [31].
Based on the results of the literature review, empirical findings in the case study and previous research, this study proposes a framework for a safety training program for work-related driving with HGVs. In addition to improve driver skills, the framework also aims to increase communication and collaboration between different parties in the system of work-related driving with HGVs.

Safety Training
This study's second aim was to propose a framework for a safety training program for work-related driving of HGVs.
A measure/intervention to increase knowledge between parties at different levels could be joint safety training and education. Safety training, education and/or competence are highlighted as crucial to safety management in several studies, e.g., [3,9,15,16,32]. This could be seen as a surprising finding in this current literature review as previous research conclusions often highlight that driver education and training have little or no effect on road traffic safety [33,34].
Even though safety training and education are highlighted as important interventions in this literature review, there is little research to be found on the content of such safety training and education. Naevestad, Elvebakk and Phillips [4] come closest to suggesting content through their safety ladder, but this study is not specific concerning the content of safety training and education for parties in the system of road transport for workrelated driving of HGVs. However, a very important statement in their study is about the complexity of the safety training. They highlight the importance of not making these programs too complex and resource-demanding. The reasoning behind this is the fact that the road transport industry is a low-earning industry, and there are few resources. Hence, complex safety programs will not be implemented due to the competition between safety and production goals.
An example of a complex safety program is the international standard ISO 39001: 2012 Road traffic safety (RTS) management systems-requirements with guidance for use. This standard is complex and demands numerous resources to implement. It is demanding for all road transport organizations to implement, in particular for small road transport organizations since they often have fewer resources to invest in safety programs.
The current study suggests a safety training framework directed towards decision makers and parties in the road transport system for work-related driving of HGVs ( Figure 1). There is an aim that the safety training framework should also be possible to implement for smaller road transport organizations. Hence, it is constructed to be simple, effective and easy to implement with few resources. Consequently, the framework is not in competition with ISO 390001: 2012 Road traffic safety (RTS) management systems, but instead it aims to be a substitute targeting both small and large road transport organizations. The suggested safety training program is divided into two parts. One training program directed towards decision makers and parties at the higher levels of the system, and one training program directed towards drivers. The reasoning between this division is based on findings in the literature review. It is stated that communication between all parties in the system is important, to ensure familiarity with each other's challenges and opportunities [30,35]. Consequently, communication is a key component of the management of road traffic safety for work-related driving of HGVs. One intervention to increase communication could be joint safety training for every party in the system.
By developing a safety training program directed towards governmental/regulatory bodies, third-parties and road transport organizations, and customizing the content towards these parties, challenges and opportunities will be made known for every party. The challenges and opportunities experienced by each party are well-documented in the research literature, and the safety training content should be based on this. Most important is that each party is made aware of other parties' challenges and opportunities, and that collaboration and cooperation are presented as an important tool to increase road traffic safety for HGV businesses and drivers.
It is suggested that an arena where governmental/regulatory bodies, third-party organizations and road transport organizations can discuss with each other is established ( Figure 1). In this arena, the different parties can present their area of responsibility as well as their challenges, e.g., regulatory bodies such as the NPRA present their concern(s) about what they detect during road traffic controls of HGVs. Road transport organizations (which own the HGVs) are given the opportunity to explain their concerns towards the same road traffic controls. By communicating to, and not against, each other, joint solutions for the challenges can be established. Furthermore, when the management of road transport organizations and buyers of road transport services communicate with each other to find solutions on time pressure, route planning, loading capacity, etc., it is assumed that challenges can be solved. By establishing such an arena for these parties, competence for each party will increase individually and as a group. Together, they will contribute to enhance the overall competence.
Finally, the actual transportation on the roads must be completed by competent drivers to minimize the possibilities of road accidents. Therefore, a safety training program aiming towards increasing the drivers' competence is of importance. In the following, a suggestion for such a training program is proposed.  [15]. The training consists of 5 modules. Modules 1-4 are mostly theoretical, with some practical tasks such as securing cargo, first aid, correct use of tire chains and correct use of fire extinguishers. Module 5 concerns the topic of 'safe behavior on the road' and consists of both theoretical classroom teaching and practical driving (EU directive 2003/59/EC). In the periodic training, most training centers spend an average of 28 h on modules 1-4 and 7 h on module 5, with around 2 h as practical driving with a professional instructor, where the aim is to drive optimally, defensively and safely [15].
A significant proportion (26.2%) of respondents in Elvebakk et al.'s study [16] completely agreed that they had improved their defensive driving skills after completing module 5. The current study therefore proposes a safety training program for HGV drivers based on two data sources:

•
Post-training studies • Results collected from actual driving training in module 5 as periodic training for professional drivers

Outcome
According to the research literature, follow-up on driver behavior is of great importance to managing road safety for work-related driving of HGVs [2,4,28,31]. By prioritizing follow-up on driver behavior, management can demonstrate their commitment to safety. The management also acknowledges company influence on and responsibility for speed and driving style [4]. When the research literature uses the phrase 'follow-up' concerning driver behavior, this mostly refers to such measures as self-monitoring facilitated by technology (e.g., on-board monitoring systems) and management monitoring and support. However, it should also be possible to suggest that driver behavior could be followed up more practically and more regularly than through periodic training every five years. The research literature therefore also highlights driver training as an important measure to increase road safety [3,15].
The current study proposes a framework for and the content of a safety training program for HGV drivers, based on module 5 'safe behavior on the road' collected from periodic training for professional drivers and from the research literature ( Table 8). The aim of this framework and content is to increase each driver's knowledge and competence. This will increase the drivers' opportunities to drive optimally, defensively and safely by making correct decisions while driving. Follow-up on driver behavior is stated to be an important measure to increase road safety for HGVs. Consequently, periodic training every five years will be too seldom to function as a follow-up on driver behavior. In addition, research shows that many transport organizations do not perform frequent follow-ups on driver behavior themselves [25]. The current study's proposed safety training program for HGV drivers is proposed to be executed between the periodic training programs every five years. Once every 6-12 months is suggested, which makes it important that the safety training program is not too time-consuming. Consequently, the framework and content suggested could be executed over two hours. It is assumed that when the training is not too time-consuming, more frequent execution of the program within each road transport organization will be possible. In between the execution of the safety training programs, it is proposed that drivers be followed up through on-board systems and dialogue with supervisors. The practical safety training program is proposed to be organized as outlined in Table 8.
For this safety training program to work, each road transport organization must educate supervisors/professional instructors. These individuals plan and schedule execution together with each driver. In this way, the program could be executed while the drivers are at work performing their regular jobs. Consequently, the resources needed to execute the program would be kept at a minimal level.

Limitations
This study does present some limitations. First, the number of articles included in the literature review was relatively low (n = 22). However, the articles included tended to describe similar challenges. It is therefore assumed that the literature review reveals the overall picture. The study was limited to factors that affect the management of road traffic safety on an organizational, third-party and driver level. Consequently, technical and mechanical factors have not been identified. Moreover, factors such as roadway geometric design and specific traffic control measures were not emphasized in this study. The reasoning behind this limitation is that the focus of the study has been on the management and their decisions at the above-mentioned levels. Second, the framework and content of the proposed safety training program were not empirically tested. It is proposed that the program should be empirically tested in future studies.

Implications and Further Research
It is assumed that the proposed safety training program will increase communication and collaboration between all parties and thereby enhance road traffic safety for workrelated driving of HGVs. As a consequence of safer road transport, it is also assumed that minor damage to vehicles and equipment will decrease. Consequently, implementation of the proposed training program will reduce road transport organizations' costs related to accidents and minor damages and the safety training program could provide a financial gain for the organization. However, more research should be conducted. It is suggested that a practical study of how the program functions within a road transport organization should be conducted.

Conclusions
This study's research questions were: (I) What are important factors to manage road traffic safety for work-related driving of HGVs? (II) How can an overall framework for safety training be arranged to enhance road traffic safety for work-related driving of HGVs? By using literature review as a method, important factors to manage road traffic safety for work-related driving of HGVs were identified. These factors were categorized at different levels in the system of road transport safety. This revealed the important factors for management of road traffic safety at the governmental level, third-party level, organizational level and driver level.
Developing and enforcing laws and regulations in line with road transport organizations and driver challenges was categorized as the most important factor at the governmental and regulatory levels. At the third-party level, the factor highlighted as important was these parties' power/opportunity to influence safety and set requirements. An important factor highlighted at the organizational level was the facilitation of good conditions for drivers. Lastly, at the driver level, skilled and experienced drivers were highlighted as important to manage road traffic safety. Most important, however, is that a systematic approach to road traffic safety for HGVs is essential. This means that every party is jointly responsible, and parties must communicate and work together to increase road traffic safety for work-related driving of HGVs.
By developing a safety training program for all parties in the system, the current study proposed a method for increased communication, collaboration and cooperation between the parties. A safety training program directed towards parties at the higher levels of the system, as well as a safety training program directed towards HGV drivers, were proposed. It is assumed that by executing a joint safety training program for parties at the higher levels of the system, parties will gain more knowledge and insight into each other's challenges and opportunities. When such knowledge is held, it is assumed that each party will be more capable of viewing things from another perspective, consequently becoming more solution-oriented. The safety training program for HGV drivers was developed with the aim of increasing HGV drivers' knowledge and competence. This will enhance the drivers' opportunities to drive optimally, defensively and safely by making correct decisions while driving.

Conflicts of Interest:
The author declares no conflict of interest. Low-claiming companies (good performing) were smaller, did more safety-related checking, checked accident history at recruitment, paid drivers for all time worked and monitored driver work and workload. High-claiming companies conducted more safety training and had more safety policies.

Appendix A
Monitoring drivers instead of safety training. Implement safety management system (SMS) that is suitable for the company's size. Thompson et al. (2015) Australia, [23] Simulated transport system (STS) using the NetLogo ABM platform (Wilensky, 2013) Determine whether agent-based modelling may be usefully applied to explore the effect of driver payment methods on driver fatigue and crash risk.
Drivers operating under 'per-km' and 'per-trip' piece rate incentive systems were significantly more likely to drive while fatigued, with the subsequent occurrence of all associated issues (loss of license, increased crash risk, increased fines), than those paid under 'flat-rate' wage conditions. Implement 'flat-rate' payment for drivers.  Increase collaboration between the transport company and others (i.e., transport buyers and regulatory bodies).
Grinerud (2021) Norway, [9] Interviews Explore how buyers of road transport services can contribute to safe road transport of goods in northern Norway and through this become important parties in reducing fatal traffic accidents.
Buyers of road transport services can contribute to safer road transport by emphasizing 5 factors: (1) develop detailed formal contracts with road transport organizations, (2) use new technology, (3) evaluate their decision criteria for ordering road transport, (4) good communication and (5) be aware of how knowledge and trust in a transport organization could affect judgement regarding revisions and controls.
Put more responsibility for safe road transport on buyers of road transport services. Increase collaboration between buyers of road transport services and road transport organizations.

Study (Country) Sample/Method Aim of Study Main Result HGV Road Safety Factors
Grinerud, Aarseth and Robertsen (2021) Norway, [25] Interviews Investigate how management decisions can affect road transport organizations' ability to develop a good safety culture.
Road transport organizations that choose a low-cost strategy struggle to be profitable. Moreover, such strategies lead to high rivalry between organizations. Such rivalry makes it difficult to be profitable, so there are fewer resources available to invest in building a good safety culture. In contrast, road transport organizations that choose a differentiation or focused leadership strategy are more likely to be profitable. As a consequence, they have more resources to invest in building a safety culture.
Management commitment and resources must be available to develop a good safety culture in road transport organizations.
Naevestad, Phillips, Levin and Hovi (2017) Norway, [29] Analysis of personal injury accident data and survey Examine the safety outcomes of increasing internationalization in Norwegian road transport of goods and discuss the importance of potential risk factors related to increasing proportions of foreign HGVs on Norwegian roads.
Foreign HGVs have a three times greater risk of single-vehicle accidents and twice the risk of head-on collisions. They are also more likely to trigger fatal accidents. Two risk factors are highlighted as important: experience with Norwegian roads and winter driving.
Foreign drivers need more experience and education in driving on Norwegian roads (especially winter driving). Buyers of road transport services need to take more responsibility for hiring competent drivers.
Elvebakk, Naevestad and Lahn (2020) Norway, [15] Document analysis, case studies and survey Evaluation of the mandatory periodic training of professional drivers in Norway.
In many ways, the periodic training is a success. Considerable numbers of students report that they have acquired new knowledge and changed their driving practice.
Education and training as a tool for safer road transport.
Naevestad, Blom and Phillips (2020) Norway, [2] Interviews and survey Validate the safety ladder approach [4] in empirical research by comparing safety structure, safety culture and accident risk for trucking companies. The study has four aims: (1) to map the safety structure at the different levels of the safety ladder, (2) examine whether safety culture is improved with increased structural measures at each safety ladder level, (3) examine whether the accident risk decreases at each safety ladder level and (4) discuss practical implications.
Based on interview results, increasing structural safety measures for the companies at each level of the safety ladder are registered. Survey results indicate increasing safety culture scores at each level of the safety ladder, while the accident risk decreases. The study concludes by suggesting the concrete management practice related to each level as good practice, as these seem to be related to the increases in safety culture and decreases in accident risk.
Safety commitment of managers and employees. Follow-up on driver behavior. Focus on work-related factors' influence on traffic safety. Safety management system.

Grinerud, Saetren and Aarseth (2020) Norway, [5] Interviews
Discuss how buyers of road transport services can contribute to sustainability and safety in the chain of transport and to the Vision-Zero Ideology.
Findings indicate that buyers of road transport services have an impact on both sustainability and safety in the chain of road transport, by exerting influence through pricing and delivery demands.
Transport buyers must set requirements for the road transport they order, be willing to pay for safe road transport and be aware of how their delivery demands have an impact on driver behavior.