1. Introduction
Traffic crashes are estimated to result in approximately 1.35 million fatalities per annum globally and a further 20 to 50 million people incur non-fatal injuries, many being permanent disabilities [
1]. The majority of these crashes take place in lower- to middle-income countries (LMICs), estimated at 93% of the world’s fatalities, but only have 60% of the world’s vehicle population [
1]. Chen, Kuhn, Prettner and Bloom [
2] estimate that this will cost the world approximately USD 1.8 trillion (in 2010 USD) between 2015 and 2030, with LMICs experiencing economic losses from fatal and non-fatal injuries of approximately USD 834 billion [
3]. Most countries’ road accidents cost more than 3% of the Gross Domestic Product [
1], although this is estimated at anything between 2% and 8% [
4]. Road traffic death rates are the highest in Africa compared to any other world region [
1], with an estimated 27 deaths per 100,000 population, compared to only 7 in Europe [
5]. Most of Africa is considered to have a high or medium-high death rate from road traffic accidents, with the exception of Mauritius (10.85 deaths per 100,000), Seychelles (10.94), Egypt (11.77) and Tunisia (16.02), which are classified as medium-low [
6]. A further 12 countries are classified as having a medium-high death rate, whilst the rest have a high death rate. The highest in Africa is Zimbabwe (also the second highest in the world after the Dominican Republic), with a death rate from traffic accidents of 63.47 per 100,000.
The WHO [
1] identifies risk factors in traffic accidents as human-related, infrastructure-related, vehicle-related and inadequate law enforcement. Road Safety Education Victoria [
7] identifies the three key areas as human factors, vehicle factors and environmental factors. The government of Jharkhand [
8] identifies the causes as human (pedestrian, driver, passenger), vehicles, road conditions and weather conditions. Of these, human errors have consistently been identified as the leading cause of accidents. In the 1980s, Treat [
9] found that 70.7% of road accidents were the result of human error, followed by environmental factors and vehicular factors. In associated earlier seminal and often cited work [
10], the authors asserted that human errors were a definite or probable cause of 90–93% of the examined incidents, with Green and Senders [
11] citing this as “human error [being] the sole cause in 57% of all accidents and was a contributing factor in over 90%”. Other studies found similar results. Salmon, Regan and Johnston [
12] cite Sabey and Taylor [
13] in finding that driver error, pedestrian error or impairment is the main contributory factor in 95% of accidents. The United Kingdom’s annual road collision statistics suggest that the majority of causes are human-related [
14], whilst the National Highway Traffic Safety Administration [
15] attributes 94% of causes of crashes directly to the driver. In South Africa, the Road Traffic Management Corporation [
16] identifies contributory factors to fatal crashes as human factors (85%), road and environmental factors (9%) and vehicle factors (7%). In Cameroon, [
17] found that less than 15% of traffic accidents can be attributed to bad roads, car defects and natural disasters, while the rest were attributable to human factors.
The link between human error and traffic safety has therefore been well established in the literature; however, as identified by the aforementioned authors, human errors can include pedestrians, drivers and passengers. The NHTSA [
15] directly attributes 94% of crashes to the driver. The RTMC [
16] in South Africa recognises that many of the human errors may be related to pedestrians or other road users (for example, cyclists); however, they indicate that the majority of fatalities due to human error are associated with the driver. Driver behaviour has thus become an important area of research, given the high incidence of driver fault in road traffic accidents. It is, however, difficult to identify the key driver behaviours that contribute most significantly to traffic accidents. The WHO [
1] identifies human-related factors as speed; alcohol and drugs; non-use of safety equipment such as helmets, child restraints and seatbelts; and distraction. The WHO also asserts that, because of these factors, age and gender may also be factors, with younger people and males being at higher risk. The report also identifies inadequate law enforcement as a key reason for accidents, arguably used to modify driver behaviour. This is generally acknowledged by African governments, as reflected by enacted laws governing alcohol consumption, use of restraints and speed restrictions, albeit that they vary significantly from country to country across the continent; for example, speed limits in urban areas in South Africa and Botswana are 60 km/h, whereas they are 50 km/h in Kenya and Zambia. Tsala et al. [
17] identified human factors as drowsiness, excessive speed, imprudence, inattention, non-respect of road signs and poor overtaking. The RTMC [
16], in their South African road fatality statistics, identified the major driving errors as speeding, overtaking in the face of oncoming traffic, intoxication, turning in front of oncoming traffic, disregarding traffic lights and signs, crossing the barrier line, U-turns, following too closely, falling asleep and cell phone use. Road Safety Education Victoria [
7] expanded driver behaviour to include deliberate risk taking and distraction to include not just cell phones but also music and friends. The Automobile Association [
18] summarised driver behaviour as speeding, distraction, drowsiness, alcohol or drugs, and adds awareness of other users and reckless driving. Moran, Baron-Epel and Assi [
19] add defiance of state authorities and low socio-economic status. Mosedale, Purdy and Clarkson [
20] add incidents involving pedestrians which are not the pedestrians’ fault and lack of anticipation or awareness (for example, looking but not seeing). Ikram and Mahajan [
21] and Haghdoost, Baneshi and Zare [
22] add education as a factor influencing driver behaviour, whilst the Transport Department Government of Jharkhand [
8] identified the failure to understand road signs. Sabey and Taylor [
13] also included inexperience, lack of judgement, aggression, recklessness, frustration and other impairments such as illness and emotional distress. Whilst human behaviours such as speeding, intoxication, attitudes, etc., are generally acknowledged as the key causes of traffic crashes, it is also recognised that the environment within which the driver functions has a strong impact on driver behaviour, for example, the road design may be such that a driver’s behaviour is influenced to reduce speed or drive in a way that is less likely to result in collision [
23], or stricter law enforcement may reduce risky driver behaviours [
24].
It is thus evident that there are significant driving habits or behaviours as well as factors that influence driving behaviour that influence traffic safety. Despite the extremely high rate of road fatalities in Africa, there is very little research on the topic within this context. The Road Traffic Management Corporation [
16] provides statistics in South Africa on the causes of road fatalities. These are generally grouped as human factors, road and environmental factors and vehicle factors. Within each factor, such as human factors, the causes are further identified as jaywalking pedestrians, speed too high, hit and run, disregarding traffic lights, intoxication, etc. The National Transport and Safety Authority [
25] collects statistics of traffic accidents in Kenya and also describes the crash as well as the causes of crashes. Statistics are produced (albeit not always readily available) for countries such as Egypt, Ghana, Nigeria and Namibia, although it is not clear whether these statistics identify accident causes, or more specifically driver behavioural issues. Whilst there are thus a few countries that identify behavioural causes of crashes, reports and statistics on behavioural causes of crashes are hard to obtain, and the majority of African countries do not have any publicly accessible statistics on the human (or other) factors underlying traffic crashes. There are several research studies that analyse causes of accidents in African countries [
17,
26,
27,
28] and several broader (and older) texts analysing road accidents in developing countries [
29], but there appears to be little research that identifies the human, specifically driver, causations of accidents in Africa, therefore making it difficult to identify interventions for what is now regarded as a “silent epidemic on wheels” [
30]. Therefore, there is a need to consider the current state of research on driver behaviour and its influence on traffic safety, to identify the current research levels and potential future research directions for this critical topic in Africa. The findings of this paper are therefore expected to provide information to practitioners and policymakers by answering the following questions: (1) what is the level and extent of driver behaviour research in relation to traffic safety in Africa? (2) what are the current research trends? and (3) what are the recommended future research directions in driver behaviour and traffic safety in Africa?
2. Materials and Methods
This study aimed at identifying and establishing the current research regarding the interaction between driver behaviour and traffic safety in Africa. An initial scoping review was used to map the literature on the level of traffic accidents or crashes, the causes of traffic accidents and the interaction between driver behaviour and traffic safety in Africa. The scoping literature review was used to identify key concepts, assess the potential nature and extent of the available literature [
31] and determine the possible gaps in the literature, for the purpose of guiding both practitioners and policymakers on the critical elements related to driver behaviour and road safety (Pham, et al., 2014). The scoping review provided rigour in identifying the elements related to driver behaviour and traffic safety in general, given that there is limited prior research into the phenomenon in Africa.
Thereafter, a bibliometric analysis was used to determine the research trends in driver behaviour and traffic safety in Africa. Whilst a meta-analysis was considered, the broad range and diversity of topics covered within the African research collection makes the collation of data and findings problematic, making bibliometric analysis appropriate to describe the research trends in the area. Bibliometric analysis is a popular and rigorous technique that enables the exploration and analysis of large amounts of scientific data to determine the “evolutionary nuances of a specific field, while shedding light on the emerging areas in that field” [
32]. It is a science mapping technique that presents data on researchers on the topic, their affiliated institutions, journals, countries, collaboration networks and themes using statistics and visualisation techniques. Studies that have used a similar technique include works on road safety injuries [
33], road safety education [
34] and accident analysis and prevention [
35]. In this paper, the bibliometric analysis is presented, firstly, as a performance analysis, which is descriptive, and secondly as scientific mapping, which largely visualises various relationships [
32]. The Web of Science database was searched for the terms driver behaviour AND traffic safety AND Africa, and sought journal articles, review papers, book chapters and conference papers. Due to very limited search results (32 initial results), the search was expanded to include driving behaviour OR driving/ driver habit (s) AND road safety. Although the search could have yielded higher results using the term “human error”, an initial investigation indicated a high level of results associated with pedestrian behaviour and was therefore excluded. The final search terms thus read (traffic OR road safety) AND (driv*) AND Africa, which yielded 192 results. As there were few results, these were scanned manually for relevance and a total of 96 items were removed due to lack of African application or results not relevant to the topic. A final list of 96 documents was analysed. For international comparison, the same search terms were used, without the addition of Africa. Over 40,000 results were returned. The high level of results suggested that a manual relevance scan was not possible; therefore, to reduce the results to a manageable base, the results were filtered for the Web of Science subject area of “Transportation”, which revealed a total of 8 461 results. Whilst this may have excluded several important sources and can therefore be regarded as a limitation to the study, the database was sufficiently large to yield enough results for meaningful comparison, given the primary focus on African research. All papers in both searches were downloaded as BibTex files. The R language was used to conduct the bibliometric analysis because it was open-source software, and therefore freely available. The Bibliometrix package was used to analyse the research papers, specifically using the Biblioshiny app, which allowed for the calculation and visualisation of the data. The main information regarding the African-related research is shown in
Table 1.
The 96 research documents identified through the bibliometric analysis were related to traffic safety and driver behaviour in Africa, revealing documents for the past 26 years. As per
Table 1, the average citations per article is 16.22 with a total of 3682 references. By contrast, an analysis of the global literature using the same search parameters revealed over 40,000 records dating back to the early 1980s, suggesting a very low level of scholarship on the topic in Africa, as well as a relatively new level of research interest.
4. Discussion
Africa is the region in the world which has the highest average accident rate and the highest number of fatalities per 100,000 population [
1], indicating a considerable need for intervention. Yet little is known about the issue. Whilst there are some accident statistics in a few countries, in general, data on accidents and traffic are hard to obtain, with Adeloye et al.’s [
79] systematic review and meta-analysis of traffic crashes, injuries and deaths identifying studies from only 15 of the 54 countries in Africa. Whilst there are a few studies originating in countries with high road accident fatality rates, e.g., Nigeria, Cameroon, Ghana, Egypt and South Africa, there are broad tracts of Africa with very high accident rates which do not reflect any research (see
Figure 3). Where research interest has been recorded, the levels remain critically low.
Figure 2 indicates that, although research interest is growing over time, this growth level is very low. Only 96 papers were produced on the topic of driver behaviour in road safety in Africa, compared to a global research interest in excess of 40,000 papers. Whilst the bibliometric analysis did not allow for statistical correlation between research and accident rates, the results from these two bibliometric profiles were contrasted to the accident rates reflected in the World Life Expectancy [
6] website and appear to reflect that higher levels of research are associated with road traffic crash and fatality rates. Policy and other interventions require data to determine road safety challenges and opportunities [
80] or, as the maxim states, ”if you can’t measure it, you can’t manage it”. As the cause of most road safety accidents is attributed to driver behaviour, it is important to understand the nature of the behaviours in order to manage this. By implication, a lack of research into the types of behaviour suggests that appropriate interventions cannot be identified and therefore implemented. Furthermore, it is important that both broad-level and country-specific research is conducted. The results of this analysis reveal that there are several differences between driver behaviours across cultures and countries [
19,
40,
57], suggesting that interventions need to be based on the driver behaviours exhibited within specific environments.
An analysis of the journals that publish most frequently on this research topic both in Africa and internationally indicates that there are many articles published in traffic- and accident-related journals, as well as medical journals, although there are some broad-range journals such as the Journal of Transport Geography, the South African Journal of Science and Sustainability. A comparison with the top 10 journals internationally includes journals relating to policy, methodological aspects and environmental aspects. Although the African list includes the journal Sustainability, environmental and sustainability aspects are under-researched in this research cohort, especially considering the sustainable development goals (SDGs) related to road safety. In particular, the United Nations declared the years 2010 to 2020 as the Decade of Action for Road Safety, and two of the SDGs relate directly to road safety. Goal 3.6 is “By 2020 halve the number of global deaths and injuries from road traffic accidents” and goal 11.2 is “By 2030 provide access to safe, affordable, accessible and sustainable transport systems for all, improving road safety, notably by expanding public transport, with special attention to the needs of those in vulnerable situations, women, children, persons with disabilities and older person” [
81]. Little research appears to consider road safety from a sustainable development perspective. Moreover, the relative lack of focus on methodological aspects suggest that research is emergent and has considerable scope for development. Although several papers consider interventions to modify selected driver behaviour, the absence of policy journals in the top 10 journal list suggests that the topic has yet to be considered from a policy perspective in Africa. The h-indices of the African-related works on the topic are relatively low, suggesting that the research lacks broad-based appeal, perhaps because of applications that are too specific or too niche, for example, traffic safety on specific roads or within specific regions. Whilst the topic of driver behaviour and traffic safety in Africa is of considerable global interest, as is evidenced by the World Health Organisation, the United Nations, Lagarde’s [
48] work, the Sustainable Development Goals, amongst others, research in the area has low citation rates, suggesting that the focus has not started to address the key or critical research gaps. A comparison of the source growth reinforces this by indicating an international focus on prevention and behavioural change, whilst the African-focused research tends to be on identification of issues within particular environments.
Table 1 shows that the majority of African-focused research is co-authored, and analysis of the countries of production (
Table 6) as well as the country collaboration network (
Figure 4) suggests that there is considerable international input into the research in Africa. However, the relatively low level of African country participation indicates, again, that the level of research from Africa is very low, but also that there is a lack of applied research from the local knowledge base. The co-citation analyses show that the African-related research focuses on the economic burden of crashes, crash issue identification, injuries and, to some extent, injury prevention. Cultural differences are also researched. International works focus on the impact of interventions as well as broader-level data analyses. By implication, the African research is still focused on identification of the key issues in driver behaviour, whereas it appears that international research has gone beyond this into intervention identification, implementation and analysis of effectiveness. The co-occurrence of keywords indicates that, whilst themes are similar in the African and international research, the linkages between African-related research themes tend to be weak, suggesting that the themes lack broad-based applicability, making it difficult to connect and form a more cohesive body of work. The thematic analysis reveals that themes such as driver behaviour are universal across both research areas, but that issues related to networks and systems approaches are missing in the African-related literature, as is model design, again suggesting the need for broader-based research and solution-driven approaches. Analysis of the highest cited papers reinforces the need for broader-based research. Lagarde [
48], for example, considered the economic burden of traffic accidents to Africa as a whole; Kouabenan [
49] provided a wide perspective on all the driver causation factors in road crashes; Nordfjærn, Jørgensen and Rundmo [
40] considered cross cultural differences; Chokotho, Matzopoulos and Myers [
53] considered the quality of traffic injury data; and Verster and Fourie [
56] provided a high level overview of factors contributing to traffic accidents. This suggests a need for research which is applicable across a range of environments.