The regional differences between countries in traffic safety: A cross-cultural study and Turkish Case

Road traffic accidents are a large problem everywhere in the world. However, regional differences in traffic safety between countries are considerable. For example, traffic safety records are much worse in Southern Europe and the Middle East than in Northern and Western Europe. Despite the large regional differences in traffic safety, factors contributing to different accident risk figures in different countries and regions have remained largely unstudied. The general aim of this study was to investigate regional differences in traffic safety between Southern European/Middle Eastern (i.e., Greece, Iran, Turkey) and Northern/Western European (i.e., Finland, Great Britain, The Netherlands) countries and to identify factors related to these differences. We conducted seven sub-studies in which I applied a traffic culture framework, including a multi-level approach, to traffic safety. We used aggregated level data (national statistics), surveys among drivers, and data on traffic accidents and fatalities in the analyses. In the first study, we investigated the influence of macro level factors (i.e., economic, societal, and cultural) on traffic safety across countries. The results showed that a high GNP per capita and conservatism correlated with a low number of traffic fatalities, whereas a high degree of uncertainty avoidance, neuroticism, and egalitarianism correlated with a high number of traffic fatalities. In the second, third, and fourth studies, we examined whether the conceptualisation of road user characteristics (i.e., driver behaviour and performance) varied across traffic cultures and how these factors determined overall safety, and the differences between countries in traffic safety. The results showed that the factorial agreement for driver behaviour (i.e., aggressive driving) and performance (i.e., safety skills) was unsatisfactory in Greece, Iran, and Turkey, where the lack of social tolerance and interpersonal aggressive violations seem to be important characteristics of driving. In addition, we found that driver behaviour (i.e., aggressive violations and errors) mediated the relationship between culture/country and accidents. Besides, drivers from "dangerous" Southern European countries and Iran scored higher on aggressive violations and errors than did drivers from "safe" Northern European countries. However, "speeding" appeared to be a "pan-cultural" problem in traffic. Similarly, aggressive driving seems largely depend on road users' interactions and drivers' interpretation (i.e., cognitive biases) of the behaviour of others in every country involved in the study. Moreover, in all countries, a risky general driving style was mostly related to being young and male. The results of the fifth and sixth studies showed that among young Turkish drivers, gender stereotypes (i.e., masculinity and femininity) greatly influence driver behaviour and performance. Feminine drivers were safety-oriented whereas masculine drivers were skill-oriented and risky drivers. Since everyday driving tasks involve not only erroneous (i.e., risky or dangerous driving) or correct performance (i.e., normal habitual driving), but also "positive" driver behaviours, we developed a reliable scale for measuring "positive" driver behaviours among Turkish drivers in the seventh study. Consequently, I revised Reason's model [Reason, J. T., 1990. Human error. Cambridge University Press: New York] of aberrant driver behaviour to represent a general driving style, including all possible intentional behaviours in traffic while evaluating the differences between countries in traffic safety. The results emphasise the importance of economic, societal and cultural factors, general driving style and skills, which are related to exposure, cognitive biases as well as age, sex, and gender, in differences between countries in traffic safety.

Factors related to seat belt use : A Turkish case

Seat belts are effective safety devices used to protect car occupants from severe injuries and fatalities during road vehicle accidents. Despite the proven effectiveness of seat belts, seat belt use rates are quite low, especially in developing countries, such as Turkey. The general aim of the present study was to investigate a large variety of factors related to seat belt use among Turkish car occupants using different perspectives and methods and therefore, to contribute to the design of effective seat belt use interventions for increasing seat belt use rates in Turkey. Five sub-studies were conducted within the present study. In the first sub-study, environmental (e.g., road type) and psycho-social factors (e.g., belt use by other car occupants) related to the seat belt use of front-seat occupants were investigated using observation techniques. Being male, of a young age, and traveling on city roads were the main factors negatively related to seat belt use. Furthermore, seat belt use by the drivers and front-seat passengers was highly correlated and a significant predictors of each other. In the second sub-study, the motivations of the car occupants for seat belt use and non-use were investigated using interview techniques. Situational conditions, such as traveling on city roads and for short distances, and not believing in the effectiveness and relevance of seat belt use for safety, were the most frequently reported reasons for not using a seat belt. Safety, habit and avoiding punishment were among the most frequently reported reasons for using a seat belt. In the third sub-study, the Theory of Planned Behavior (TPB) and the Health Belief Model (HBM) were applied to seat belt use using Structural Equation Modeling techniques. The TPB model showed a good fit to the data, whereas the HBM showed a poor fit to the data. Within the TPB model, attitude and subjective norm were significant predictors of intentions to use a seat belt on both urban and rural roads. In the fourth sub-study, seat belt use frequency and motivations for seat belt use among taxi drivers were investigated and compared between free-time and work-time driving using a survey. The results showed that taxi drivers used seat belts more when driving a private car in their free-times compared to when driving a taxi during their work-times. The lack of a legal obligation to use a seat belt in city traffic and fear of being attacked or robbed by the passengers were found as two specific reasons for not using a seat belt when driving a taxi. Lastly, in the fifth sub-study, the relationship of seat belt use to driver and health behaviors was investigated using a survey. Although seat belt use was related both to health and driver behaviors, factor analysis results showed that it grouped with driver behaviors. Based on the results of the sub-studies, a tentative empirical model showing different predictors of seat belt use was proposed. According to the model, safety and normative motivations and perceived physical barriers related to seat belt use are the three important predictors of seat belt use. Keywords: Seat belt use; environmental factors; psycho-social factors; safety and normative motivations; the Theory of Planned Behavior; the Health Belief Model; health behaviors; driver behaviors; front-seat occupants; taxi drivers; Turkey.

Fatigued driving : prevalence, risk factors and groups, and the law

Fatigue and sleepiness are major causes of road traffic accidents. However, precise data is often lacking because a validated and reliable device for detecting the level of sleepiness (cf. the breathalyzer for alcohol levels) does not exist, nor does criteria for the unambiguous detection of fatigue/sleepiness as a contributing factor in accident causation. Therefore, identification of risk factors and groups might not always be easy. Furthermore, it is extremely difficult to incorporate fatigue in operationalized terms into either traffic or criminal law. The main aims of this thesis were to estimate the prevalence of fatigue problems while driving among the Finnish driving population, to explore how VALT multidisciplinary investigation teams, Finnish police, and courts recognize (and prosecute) fatigue in traffic, to identify risk factors and groups, and finally to explore the application of the Finnish Road Traffic Act (RTA), which explicitly forbids driving while tired in Article 63. Several different sources of data were used: a computerized database and the original folders of multidisciplinary teams investigating fatal accidents (VALT), the driver records database (AKE), prosecutor and court decisions, a survey of young male military conscripts, and a survey of a representative sample of the Finnish active driving population. The results show that 8-15% of fatal accidents during 1991-2001 were fatigue related, that every fifth Finnish driver has fallen asleep while driving at some point during his/her driving career, and that the Finnish police and courts punish on average one driver per day on the basis of fatigued driving (based on the data from the years 2004-2005). The main finding regarding risk factors and risk groups is that during the summer months, especially in the afternoon, the risk of falling asleep while driving is increased. Furthermore, the results indicate that those with a higher risk of falling asleep while driving are men in general, but especially young male drivers including military conscripts and the elderly during the afternoon hours and the summer in particular; professional drivers breaking the rules about duty and rest hours; and drivers with a tendency to fall asleep easily. A time-of-day pattern of sleep-related incidents was repeatedly found. It was found that VALT teams can be considered relatively reliable when assessing the role of fatigue and sleepiness in accident causation; thus, similar experts might be valuable in the court process as expert witnesses when fatigue or sleepiness are suspected to have a role in an accident’s origins. However, the application of Article 63 of the RTA that forbids, among other things, fatigued driving will continue to be an issue that deserves further attention. This should be done in the context of a needed attitude change towards driving while in a state of extreme tiredness (e.g., after being awake for more than 24 hours), which produces performance deterioration comparable to illegal intoxication (BAC around 0.1%). Regarding the well-known interactive effect of increased sleepiness and even small alcohol levels, the relatively high proportion (up to 14.5%) of Finnish drivers owning and using a breathalyzer raises some concern. This concern exists because these drivers are obviously more focused on not breaking the “magic” line of 0.05% BAC than being concerned about driving impairment, which might be much worse than they realize because of the interactive effects of increased sleepiness and even low alcohol consumption. In conclusion, there is no doubt that fatigue and sleepiness problems while driving are common among the Finnish driving population. While we wait for the invention of reliable devices for fatigue/sleepiness detection, we should invest more effort in raising public awareness about the dangerousness of fatigued driving and educate drivers about how to recognize and deal with fatigue and sleepiness when they ultimately occur.

Analysis of Heterogeneous IP Traffic in Wireless Environment

Wireless access is expected to play a crucial role in the future of the Internet. The demands of the wireless environment are not always compatible with the assumptions that were made on the era of the wired links. At the same time, new services that take advantage of the advances in many areas of technology are invented. These services include delivery of mass media like television and radio, Internet phone calls, and video conferencing. The network must be able to deliver these services with acceptable performance and quality to the end user. This thesis presents an experimental study to measure the performance of bulk data TCP transfers, streaming audio flows, and HTTP transfers which compete the limited bandwidth of the GPRS/UMTS-like wireless link. The wireless link characteristics are modeled with a wireless network emulator. We analyze how different competing workload types behave with regular TPC and how the active queue management, the Differentiated services (DiffServ), and a combination of TCP enhancements affect the performance and the quality of service. We test on four link types including an error-free link and the links with different Automatic Repeat reQuest (ARQ) persistency. The analysis consists of comparing the resulting performance in different configurations based on defined metrics. We observed that DiffServ and Random Early Detection (RED) with Explicit Congestion Notification (ECN) are useful, and in some conditions necessary, for quality of service and fairness because a long queuing delay and congestion related packet losses cause problems without DiffServ and RED. However, we observed situations, where there is still room for significant improvements if the link-level is aware of the quality of service. Only very error-prone link diminishes the benefits to nil. The combination of TCP enhancements improves performance. These include initial window of four, Control Block Interdependence (CBI) and Forward RTO recovery (F-RTO). The initial window of four helps a later starting TCP flow to start faster but generates congestion under some conditions. CBI prevents slow-start overshoot and balances slow start in the presence of error drops, and F-RTO reduces unnecessary retransmissions successfully.

Quantifying Time Awake Posturographically

This thesis focuses on the issue of testing sleepiness quantitatively. The issue is relevant to policymakers concerned with traffic- and occupational safety; such testing provides a tool for safety legislation and -surveillance. The findings of this thesis provide guidelines for a posturographic sleepiness tester. Sleepiness ensuing from staying awake merely 17 h impairs our performance as much as the legally proscribed blood alcohol concentration 0.5 does. Hence, sleepiness is a major risk factor in transportation and occupational accidents. The lack of convenient, commercial sleepiness tests precludes testing impending sleepiness levels contrary to simply breath testing for alcohol intoxication. Posturography is a potential sleepiness test, since clinical diurnal balance testing suggests the hypothesis that time awake could be posturographically estimable. Relying on this hypothesis this thesis examines posturographic sleepiness testing for instrumentation purposes. Empirical results from 63 subjects for whom we tested balance with a force platform during wakefulness for maximum 36 h show that sustained wakefulness impairs balance. The results show that time awake is posturographically estimable with 88% accuracy and 97% precision which validates our hypothesis. Results also show that balance scores tested at 13:30 hours serve as a threshold to detect excessive sleepiness. Analytical results show that the test length has a marked effect on estimation accuracy: 18 s tests suffice to identify sleepiness related balance changes, but trades off some of the accuracy achieved with 30 s tests. The procedure to estimate time awake relies on equating the subject s test score to a reference table (comprising balance scores tested during sustained wakefulness, regressed against time awake). Empirical results showed that sustained wakefulness explains 60% of the diurnal balance variations, whereas the time of day explains 40% of the balance variations. The latter fact implies that time awake estimations also must rely on knowing the local times of both test and reference scores.

Arrested Drunk Drivers : Trends, social background, recidivism and mortality

The aim of this study was to examine the trends, incidence and recidivism of drunken driving during a 20-year period (1988 - 2007) using the data on all suspected drunken driving in this period. Furthermore, the association between social background and drunken driving, and the mortality of drunk drivers were studied by using administrative register data provided by Statistics Finland. The study was completely register-based. In 1989 - 1991, every year 30,000 drivers were suspected of drunken driving, but the number fell to less than 20,000 by 1994, during the economic recession. The changes in the arrest incidence of the youngest age groups were especially pronounced, most of all in the age group of 18 - 19-year olds. Even though the incidence among youth decreased dramatically, their incidence rate was still twice that of the general population aged 15 - 84 years. Drunken driving was associated with a poor social background among youth and working-aged men and women. For example, a low level of education, unemployment, divorce, and parental factors in youth were associated with a higher risk of being arrested for drunken driving. While a low income was related to more drunken driving among working-aged people, the effect among young persons was the opposite. Every third drunk driver got rearrested during a 15-year period, whereas the estimated rearrest rate was 44%. Findings of drugs only or in combination with alcohol increased the risk of rearrest. The highest rearrest rates were seen among drivers who were under the influence of amphetamines or cannabis. Also male gender, young age, high blood alcohol concentration, and arrest during weekdays and in the daytime predicted rearrest. When compared to the general population, arrested drunk drivers had significant excess mortality. The greatest relative differences were seen in alcohol-related causes of death (including alcohol diseases and alcohol poisoning), accidents, suicides and violence. Also mortality due to other than alcohol-related diseases was elevated among drunk drivers. Drunken driving was associated with multiple factors linked to traffic safety, health and social problems. Social marginalization may expose a person to harmful use of alcohol and drunken driving, and the associations are seen already among the youth. Recidivism is common among drunk drivers, and driving under the influence of illicit and/or medicinal drugs is likely to indicate worse substance abuse problems, judging from the high rearrest rates. High alcohol-related mortality in this population shows that drunken driving is clearly an indicator of alcohol abuse. More effective measures of preventing alcohol-related harms are needed, than merely preventing convicted drunk drivers from driving again.

Professional Driving : An Emphasis on Organizational Safety Climate

According to the literature and statistical figures, professional drivers constitute a high-risk group in traffic and should be investigated in connection with the factors related to safe driving. However, safety-related behaviours and outcomes among professional drivers have attracted very little attention from safety researchers. In addition, comparing different professional and non-professional driver groups in terms of critical on-the-road characteristics and outcomes has been indicated in the literature as being necessary for a more comprehensive understanding of driver groups and the nature of driving itself. The aim of the present study was to investigate professional driving from a safety climate stand point in relation to predominant driving-related factors and by considering the differences between driver groups. Hence, four Sub-studies were conducted according to a framework emphasizing the relationships between safety climate, driver groups, driver stress, human factors (i.e., driver behaviour and performance) and accidents. Demographic information, as well as data for driver behaviour, performance, and driver stress was collected by questionnaire. The data was analysed using factor analysis, analysis of covariance as well as hierarchical and logistic regression analysis. The results revealed multi-dimensional factor structures for the safety climate measures. Considering the relationships between variables, differences were evidenced regarding on-the-road stress reactions, risky driver behaviours and penalties, between the various professional and non-professional driver groups. Driver stress was found to be related to accidents. The results also indicated that the safety climate has positive relationships with both driver behaviour and performance, and as well as involvement in accidents. The present study has a number of critical implications resulting from the fact that the way in which the effects of safety climate on professional driving were investigated, as well as the differences between professional and non-professional driver groups, was unique. Additionally, for the first time, a safety climate scale was developed specifically for professional drivers. According to the results of the study and to previous literature, a tentative model was proposed representing a possible route for the relationships between safety climate, human factors, driver stress, driver groups and accidents, by emphasizing the effects of safety climate.