[Safety measures in traffic; how risk compensation affects our behaviour]. / Veiligheidsmaatregelen in het verkeer.

In 2020, more than 600 people died as a result of a traffic crash in the Netherlands and 6,500 were hospitalized after they had sustained a serious injury (MAIS 3+). These numbers are much lower than those in the beginning of the seventies of the last century, when there were more than 3,000 road fatalities. To reduce the number of fatalities, many measures have been taken to avoid road crashes and reduce injury severity. By road design that makes it impossible for road users to collide, by improving the safety of vehicles, and by educating road users. Traffic psychologists often warn for behavioural adaptations that nullify the expected effect of road safety measures (risk compensation). Numerous studies have shown examples of risk compensation in traffic. What is the psychological mechanism behind risk compensation? Which factors enhance risk compensation? And are there any advantages of risk compensation?

Are There Any Significant Differences in Terms of Age and Sex in Pedestrian and Cyclist Accidents?

This study has analyzed sex-specific differences in pedestrian and cyclist accidents involving passenger cars. The most frequently injured body regions, types of injuries, which show sex-specific differences and the general accident parameters of females and males were compared. Accident data from three different European countries (Austria, Netherlands, Sweden) were analyzed. The current analysis shows that for both, females and males, pedestrian and cyclist injuries are sustained mainly to the body regions head, thorax, upper extremities and lower extremities. The results show that the odds for sustaining skeletal injuries to the lower extremities (incl. pelvis) in females are significantly higher. It was observed in all datasets, that the odds of females being involved in a rural accident or an accident at night are lower than for males. Elderly pedestrian and cyclist (≥60YO) tend to sustain more severe injuries (AIS2+ and AIS3+) than younger pedestrian and cyclists (<60YO) in some of the datasets. The findings of this study highlight the differences in males and females in both, accident scenarios and sustained injuries. Further investigations are needed to distinguish between gender- and sex-specific differences causing the different injury patterns.

Investigation of accidents involving powered two wheelers and bicycles - A European in-depth study.

INTRODUCTION: The number of road fatalities have been falling throughout the European Union (EU) over the past 20 years and most Member States have achieved an overall reduction. Research has mainly focused on protecting car occupants, with car occupant fatalities reducing significantly. However, recently there has been a plateauing in fatalities amongst 'Vulnerable Road Users' (VRUs), and in 2016 accidents involving VRUs accounted for nearly half of all EU road deaths. METHOD: The SaferWheels study collected in-depth data on 500 accidents involving Powered Two-Wheelers (PTWs) and bicycles across six European countries. A standard in-depth accident investigation methodology was used by each team. The Driver Reliability and Error Analysis Method (DREAM) was used to systematically classify accident causation factors. RESULTS: The most common causal factors related to errors in observation by the PTW/bicycle rider or the driver of the other vehicle, typically called 'looked but failed to see' accidents. Common scenarios involved the other vehicle turning or crossing in front of the PTW/bicycle. A quarter of serious or fatal injuries to PTW riders occurred in accidents where the rider lost control with no other vehicle involvement. CONCLUSIONS: Highly detailed data have been collected for 500 accidents involving PTWs or bicycles in the EU. These data can be further analyzed by researchers on a case-study basis to gain detailed insights on such accidents. Preliminary analysis suggests that 'looked but failed to see' remains a common cause, and in many cases the actions of the other vehicle were the critical factor, though PTW rider speed or inexperience played a role in some cases. Practical Applications: The collected data can be analyzed to better understand the characteristics and causes of accidents involving PTWs and bicycles in the EU. The results can be used to develop policies aimed at reducing road deaths and injuries to VRUs.

Analysis of Swedish and Dutch accident data on cyclist injuries in cyclist-car collisions.

Objective: To reduce the number of severe injuries sustained by cyclists in crashes with vehicles, it is important to understand which kinds of injuries are occurring to identify what should be assessed by means of virtual testing.Method: A detailed analysis of injuries was made based on Swedish and Dutch accident data. The most frequently injured body regions and the most frequent single injuries of these body regions were analysed.Results: Cyclists most frequently injured their heads, upper and lower extremities, and bone fractures as well as brain injuries were identified as one of the most important injuries.Conclusions: For the virtual assessment of cyclist protection, injury predictors for long bone, skull and pelvic fractures as well as brain injuries are required in Human Body Models.

Driving Difficulties Among Patients with Alzheimer's Disease and Other Neurodegenerative Disorders.

BACKGROUND/OBJECTIVE: Neurodegenerative disorders impact fitness to drive of older drivers, but on-road driving studies investigating patients with different neurodegenerative disorders are scarce. A variety of driving errors have been reported in patients with Alzheimer's disease (AD), but it is unclear which types of driving errors occur most frequently. Moreover, patients with other neurodegenerative disorders than AD typically present with different symptoms and impairments, therefore different driving errors may be expected. METHODS: Patients with AD (n = 80), patients with other neurodegenerative disorders with cognitive decline (i.e., vascular dementia, frontotemporal dementia, dementia with Lewy bodies/Parkinson's disease, n = 59), and healthy older drivers (n = 45) participated in a fitness-to-drive assessment study including on-road driving. RESULTS: Patients with AD performed significantly worse than healthy older drivers on operational, tactical, visual, and global aspects of on-road driving. In patients with AD, on-road measures were significantly associated with 'off-road' measures. Patients with neurodegenerative disorders other than AD showed large overlap in the types of driving errors. Several driving errors were identified that appear to be characteristic for patients with particular neurodegenerative disorders. CONCLUSION: Patients from each group of neurodegenerative disorders commonly display tactical driving errors regarding lane positioning, slow driving, observation of the blind spot, and scanning behavior. Several other tactical and operational driving errors, including not communicating with cyclists and unsteady steering, were more frequently observed in patients with non-AD neurodegenerative disorders. These findings have implications for on-road and 'off-road' fitness-to-drive assessments for patients with neurodegenerative disorders with cognitive decline.

Adherence to driving cessation advice given to patients with cognitive impairment and consequences for mobility.

BACKGROUND: Driving is related to social participation; therefore older drivers may be reluctant to cease driving. Continuation of driving has also been reported in a large proportion of patients with cognitive impairment. The aim of this study is to investigate whether patients with cognitive impairment adhere to driving cessation advice after a fitness-to-drive assessment and what the consequences are with regard to mobility. METHODS: Patients with cognitive impairment (n = 172) participated in a fitness-to-drive assessment study, including an on-road driving assessment. Afterwards, patients were advised to either continue driving, to follow driving lessons, or to cease driving. Approximately seven months thereafter, patients were asked in a follow-up interview about their adherence to the driving recommendation. Factors influencing driving cessation were identified using a binary logistic regression analysis. Use of alternative transportation was also evaluated. RESULTS: Respectively 92 and 79% of the patients adhered to the recommendation to continue or cease driving. Female gender, a higher Clinical Dementia Rating-score, perceived health decline, and driving cessation advice facilitated driving cessation. Patients who ceased driving made use of less alternative modes of transportation than patients who still drove. Nonetheless, around 40% of the patients who ceased driving increased their frequency of cycling and/or public transport use. CONCLUSIONS: Adherence to the recommendations given after the fitness-to-drive assessments was high. Female patients were in general more likely to cease driving. However, a minority of patients did not adhere to driving cessation advice. These drivers with dementia should be made aware of the progression of their cognitive impairment and general health decline to facilitate driving cessation. There are large differences in mobility between patients with cognitive impairment. Physicians should discuss options for alternative transportation in order to promote sustained safe mobility of patients with cognitive impairment.

Assessing Fitness to Drive in Patients With Different Types of Dementia.

Dementia is a risk factor for unsafe driving. Therefore, an assessment strategy has recently been developed for the prediction of fitness to drive in patients with the Alzheimer disease (AD). The aim of this study was to investigate whether this strategy is also predictive of fitness to drive in patients with non-AD dementia, that is, vascular dementia, frontotemporal dementia, and dementia with Lewy bodies. Predictors were derived from 3 types of assessment: clinical interviews, neuropsychological tests, and driving simulator rides. The criterion was the pass-fail outcome of an official on-road driving assessment. About half of the patients with non-AD dementia (n=34) failed the on-road driving assessment. Neuropsychological assessment [area under the curve (AUC)=0.786] was significantly predictive of fitness to drive in patients with non-AD dementia, however, clinical interviews (AUC=0.559) and driving simulator rides (AUC=0.404) were not. The fitness-to-drive assessment strategy with the 3 types of assessment combined (AUC=0.635) was not found to significantly predict fitness to drive in non-AD dementia. Different types of dementia require different measures and assessment strategies.

Assessing fitness to drive-A validation study on patients with mild cognitive impairment.

OBJECTIVES: There is no consensus yet on how to determine which patients with cognitive impairment are able to drive a car safely and which are not. Recently, a strategy was composed for the assessment of fitness to drive, consisting of clinical interviews, a neuropsychological assessment, and driving simulator rides, which was compared with the outcome of an expert evaluation of an on-road driving assessment. A selection of tests and parameters of the new approach revealed a predictive accuracy of 97.4% for the prediction of practical fitness to drive on an initial sample of patients with Alzheimer's dementia. The aim of the present study was to explore whether the selected variables would be equally predictive (i.e., valid) for a closely related group of patients; that is, patients with mild cognitive impairment (MCI). METHODS: Eighteen patients with mild cognitive impairment completed the proposed approach to the measurement of fitness to drive, including clinical interviews, a neuropsychological assessment, and driving simulator rides. The criterion fitness to drive was again assessed by means of an on-road driving evaluation. The predictive validity of the fitness to drive assessment strategy was evaluated by receiver operating characteristic (ROC) analyses. RESULTS: Twelve patients with MCI (66.7%) passed and 6 patients (33.3%) failed the on-road driving assessment. The previously proposed approach to the measurement of fitness to drive achieved an overall predictive accuracy of 94.4% in these patients. The application of an optimal cutoff resulted in a diagnostic accuracy of 100% sensitivity toward unfit to drive and 83.3% specificity toward fit to drive. Further analyses revealed that the neuropsychological assessment and the driving simulator rides produced rather stable prediction rates, whereas clinical interviews were not significantly predictive for practical fitness to drive in the MCI patient sample. CONCLUSIONS: The selected measures of the previously proposed approach revealed adequate accuracy in identifying fitness to drive in patients with MCI. Furthermore, a combination of neuropsychological test performance and simulated driving behavior proved to be the most valid predictor of practical fitness to drive.

Prediction of Fitness to Drive in Patients with Alzheimer's Dementia.

The number of patients with Alzheimer's disease (AD) is increasing and so is the number of patients driving a car. To enable patients to retain their mobility while at the same time not endangering public safety, each patient should be assessed for fitness to drive. The aim of this study is to develop a method to assess fitness to drive in a clinical setting, using three types of assessments, i.e. clinical interviews, neuropsychological assessment and driving simulator rides. The goals are (1) to determine for each type of assessment which combination of measures is most predictive for on-road driving performance, (2) to compare the predictive value of clinical interviews, neuropsychological assessment and driving simulator evaluation and (3) to determine which combination of these assessments provides the best prediction of fitness to drive. Eighty-one patients with AD and 45 healthy individuals participated. All participated in a clinical interview, and were administered a neuropsychological test battery and a driving simulator ride (predictors). The criterion fitness to drive was determined in an on-road driving assessment by experts of the CBR Dutch driving test organisation according to their official protocol. The validity of the predictors to determine fitness to drive was explored by means of logistic regression analyses, discriminant function analyses, as well as receiver operating curve analyses. We found that all three types of assessments are predictive of on-road driving performance. Neuropsychological assessment had the highest classification accuracy followed by driving simulator rides and clinical interviews. However, combining all three types of assessments yielded the best prediction for fitness to drive in patients with AD with an overall accuracy of 92.7%, which makes this method highly valid for assessing fitness to drive in AD. This method may be used to advise patients with AD and their family members about fitness to drive.

Car drivers with dementia: Different complications due to different etiologies?

OBJECTIVE: Older drivers with dementia are an at-risk group for unsafe driving. However, dementia refers to various etiologies and the question is whether dementias of different etiology have similar effects on driving ability. METHODS: The literature on the effects of dementia of various etiologies on driving ability is reviewed. Studies addressing dementia etiologies and driving were identified through PubMed, PsychINFO, and Google Scholar. RESULTS AND CONCLUSIONS: Early symptoms and prognoses differ between dementias of different etiology. Therefore, different etiologies may represent different likelihoods with regard to fitness to drive. Moreover, dementia etiologies could indicate the type of driving problems that can be expected to occur. However, there is a great lack of data and knowledge about the effects of almost all etiologies of dementia on driving. One could hypothesize that patients with Alzheimer's disease may well suffer from strategic difficulties such as finding a route, whereas patients with frontotemporal dementia are more inclined to make tactical-level errors because of impaired hazard perception. Patients with other dementia etiologies involving motor symptoms may suffer from problems on the operational level. Still, the effects of various etiologies of dementias on driving have thus far not been studied thoroughly. For the detection of driving difficulties in patients with dementia, structured interviews with patients but also their family members appear crucial. Neuropsychological assessment could support the identification of cognitive impairments. The impact of such impairments on driving could also be investigated in a driving simulator. In a driving simulator, strengths and weaknesses in driving behavior can be observed. With this knowledge, patients can be advised appropriately about their fitness to drive and options for support in driving (e.g., compensation techniques, car adaptations). However, as long as no valid, reliable, and widely accepted test battery is available for the assessment of fitness to drive, costly on-road test rides are inevitable. The development of a fitness-to-drive test battery for patients with dementia could provide an alternative for these on-road test rides, on condition that differences between dementia etiologies are taken into consideration.

Effects of in-car support on mental workload and driving performance of older drivers.

OBJECTIVE: This study examined the extent to which driving performance of 10 older (70-88 years old) and 30 younger participants (30-50 years old) improves as a result of support by a driver assistance system. BACKGROUND: Various studies have indicated that advanced driver assistance systems (ADAS) may provide tailored assistance for older drivers and thereby improve their safe mobility. METHOD: While drivers followed an urban route in a driving simulator, an ADAS provided them with prior knowledge on the next intersection. The system was evaluated in terms of effects on workload and safety performance. RESULTS: Messages informing drivers about the right-of-way regulation, obstructed view of an intersection, and safe gaps to join or cross traffic streams led to safer driving performance. A message regarding an unexpected one-way street led to fewer route errors. In general, effects were the same for all age groups. Workload was not reduced by the support system. CONCLUSION: The evaluated support system shows promising effects for all age groups. Longer evaluation periods are needed to determine long-term effects. APPLICATION: The messages provided by the evaluated system are currently not provided by existing ADAS such as advanced cruise control and navigation systems, but they could possibly be added to them in the future.

The effects of an edgeline on speed and lateral position: a meta-analysis.

This paper presents a meta-analysis of studies that have evaluated the effects of an edgeline on speed and lateral position of motorised road users. Together with many other study characteristics, 41 estimates of the effects of an edgeline on speed and 65 on lateral position were extracted from the studies. The results of the evaluation studies show a great variety in effects. Both negative and positive effects on speed and lateral position were found; amongst others, increases in speed up to 10.6 km/h, as well as decreases in speed up to 5.0 km/h, and shifts of the lateral position towards the centre of the road up to 30 cm, as well as shifts towards the edge of the road up to 35 cm. Further analyses resulted in the determination of study characteristics that influence the effects of an edgeline on speed and lateral position. It is concluded that the effects of an edgeline on speed are related to the presence of a centreline. Applying an edgeline to a road without a centreline increases the speed of road users, and replacing a centreline by an edgeline decreases the speed. Results with respect to adding an edgeline to a road with a centreline were unclear. Another conclusion is that shoulder width and road environment contribute to the effects of an edgeline on lateral position. In combination with wide shoulders or buildings and/or trees next to the road, edgelines lead to shifts of the lateral position towards the edge of the road, and in combination with narrow shoulders or open fields, edgelines lead to shifts towards the centre of the road.