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This chapter covers design of rural roads according to the model for safe traffic used in the Vision Zero approach. Based on expected levels of the safety of vehicles and road users, the roads and the road side furniture should be designed to avoid fatalities and serious injuries. An introduction is presented covering the safe system approach and how speed limits of roads should be set to reflect the safety standard of the road in relation human injury tolerance and the capacity to protect the road users. One section will cover countermeasures to protect vulnerable road users, including speed calming road infrastructure, bicycle and pedestrian paths, bus stops. Another section will cover road infrastructure countermeasures addressing vehicle occupants. It is shown how change of velocity, vehicle mean acceleration, and crash duration are correlated and how they influence occupant injury risk. Design of different types of roads on rural roads is described, such as the two-plus-one lane road design with median barrier, and various ways of separating traffic or preventing run-off road crashes including road barrier design and rumble strips. Safe intersection design is an important part on rural roads that is explained. The last part covers design of the roadside area from a safe system approach.

Objective: The objective of this article is to describe the characteristics of fatal crashes with bicyclists on Swedish roads in rural and urban areas and to investigate the potential of bicycle helmets and different vehicle and road infrastructure interventions to prevent them. The study has a comprehensive approach to provide road authorities and vehicle manufacturers with recommendations for future priorities. Methods: The Swedish Transport Administration’s (STA) in-depth database of fatal crashes was used for case-by-case analysis of fatal cycling accidents (2006–2016) on rural (n = 82) and urban (n = 102) roads. The database consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. The potential of helmet use and various vehicle and road infrastructure safety interventions was determined retrospectively for each case by analyzing the chain of events leading to the fatality. The potential of vehicle safety countermeasures was analyzed based on prognoses on their implementation rates in the Swedish vehicle fleet. Results: The most common accident scenario on rural roads was that the bicyclist was struck while cycling along the side of the road. On urban roads, the majority of accidents occurred in intersections. Most accidents involved a passenger car, but heavy trucks were also common, especially in urban areas. Most accidents occurred in daylight conditions (73%). Almost half (46%) of nonhelmeted bicyclists would have survived with a helmet. It was assessed that nearly 60% of the fatal accidents could be addressed by advanced vehicle safety technologies, especially autonomous emergency braking with the ability to detect bicyclists. With regard to interventions in the road infrastructure, separated paths for bicyclists and bicycle crossings with speed calming measures were found to have the greatest safety potential. Results indicated that 91% of fatally injured bicyclists could potentially be saved with known techniques. However, it will take a long time for such technologies to be widespread. Conclusions: The majority of fatally injured bicyclists studied could potentially be saved with known techniques. A speedy implementation of important vehicle safety systems is recommended. A fast introduction of effective interventions in the road infrastructure is also necessary, preferably with a plan for prioritization.

Improvements in road infrastructure and vehicle safety have been achieved in many countries during the last decades. As the number of fatalities have dropped, the consequences of non-fatal injuries have been brought into focus. Therefore, the objective was to investigate self-reported health status and health-related quality of life several years after the crash for road-users that sustained injuries resulting in permanent medical impairment (PMI).A self-administered questionnaire using instruments to measure if health, health-related quality of life and physical activity had been affected by the crash, were used. The injured road-users were identified from insurance policy holders of the Folksam Insurance Group. The response rate was 29%, a total of 2078 responses were received from the 7174 road-users with PMI that received the questionnaire.In total 85% were still suffering from the injuries several years after the crash (8-18 year after the crash). Furthermore, road-users with injuries to the spine were having highest pain intensity. Older road-users had poorer self-reported health status than younger road-users. Although, younger road-users had the greatest change in physical activity when comparing before and after the crash. Before the crash in total 63% were physically active while only 34% after the crash. The higher the PMI the higher it affected health several years after the crash.The Swedish definition of serious injury, an injury leading to PMI, was found to correlate with self-reported health loss; 85% of the injured road-users reported that they still had remaining symptoms several years after the accident. The injured body region leading to PMI after an accident can vary from the body regions reported to cause long-term health loss. It was found that the higher the degree of PMI the higher the health loss. Sustaining a PMI regardless severity and injured body region has the same effects on general health for men and women. Sustaining a PMI will both lower the health-related quality of life and physical activity after the crash compared to before.

Objective: As bicyclists account for the largest share of serious injuries in Sweden, focus to improve safety for bicyclists is needed. While knowledge about fatal bicycle crashes is rather extensive, the number of studies that have investigated non-fatal injuries is still rather limited. The aim of this study was to estimate the potential of different countermeasures to reduce crashes resulting in injuries with high risk of health-loss among cyclists in Sweden. A further aim was to describe the residual—that is, crashes that were not considered to be addressed by the analyzed countermeasures. Methods: A sample of individuals with specific injury diagnoses was drawn from the Swedish national crash database Strada. A survey form was used to collect additional information about the crash and the health-related outcomes. The potential of countermeasures currently included in the Swedish Safety Performance Indicators, as well as of countermeasures that could be described as “existing but not fully implemented” was assessed. The overall potential of all countermeasures assessed was calculated, giving a grand total without double counting. Cases that were considered not to be addressed by any of the countermeasures included (i.e., the residual crashes) were described in more detail. Results: The current Swedish Safety Performance Indicators that relate to safe cycling addressed 22% of crashes. Improved maintenance by deicing and removal of snow from bicycle infrastructure was found to have the highest potential (8%), followed by improved crashworthiness of passenger cars (5%) and safer bicycle crossings (4%). The potential for existing but not fully implemented safety improvements was 56%. The greatest potential was found for Autonomous Emergency Braking with cyclist detection for passenger cars (12%), followed by studded winter tyres for bicycles (12%), and improved maintenance on non-bicycle infrastructure (11%). In total, taking double counting into consideration, all safety improvements could address 64% of all crashes. Among the residual crashes, the majority (69%) were single bicycle crashes of which most were related to wheel locking during braking and losing balance at low speed or stationary. Conclusions: Compared with fatal crashes that involve a majority of bicycle-car crashes, the crashes leading to health-loss are mostly single bicycle crashes. Therefore, innovation and development of additional countermeasures to improve safety for bicyclists should focus on single bicycle crashes.

Objectives: Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.Methods: The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.Results: The EvaRID V1.0 model and the volunteer tests compared well until ∼250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.Conclusions: The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.

Objective: The objective was to identify whether it was possible to change driver behavior by economic incentives and thereby reduce crash risk. Furthermore, the objective was to evaluate the participants' attitudes toward the pay-as-you-speed (PAYS) concept. Methods: A one-year PAYS trial with economic incentives for keeping speed limits using intelligent speed assistance (ISA) was conducted in Sweden during 2011-2012. The full incentive was a 30 percent discount off the insurance premium. The participants were private insurance customers and were randomized into a test group (initial n = 152, final n = 128) and a control group (initial n = 98, final n = 68). When driving, the drivers in the test group were informed and warned visually when the speed limit was exceeded. They could also follow their driving results on a personal website. The control group was not given any feedback at all. To reflect the impact of the PAYS concept the proportion of distance driven above the speed limit was compared between the 2 groups. Results: The introduction of a PAYS concept shows that the test group significantly reduced the proportion of distance driven above the speed limit. The proportion of driving at a speed exceeding 5 km/h over the speed limit was 6 percent for the test group and 14 percent for the control group. It also showed that the effect was higher the higher the violation of speed. The result remained constant over time. Conclusions: It was shown that a PAYS concept is an effective way to reduce speed violations. Hence, it has the possibility to reduce crash severity and thereby to save lives. This could be an important step toward a safer road transport system. The majority of the participants were in favor of the concept, which indicates the potential of a new insurance product in the future.

In this paper, a test-based assessment method for pre-crash warning and braking systems is presented where the effectiveness of a system is measured by its ability to reduce the number of injuries of a given type or severity in car-to-car rear-end collisions. Injuries with whiplash symptoms lasting longer than 1 month and MAIS2+ injuries in both vehicles involved in the crash are considered in the assessment. The injury reduction resulting from the impact speed reduction due to a pre-crash system is estimated using a method which has its roots in the dose-response model. Human-machine interaction is also taken into account in the assessment. The results reflect the self-protection as well as the partner-protection performance of a pre-crash system in the striking vehicle in rear-end collisions and enable a comparison between two or more systems. It is also shown how the method may be used to assess the importance of warning as part of a pre-crash system.

Objective: Whiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically Methods: The seated positions of drivers in stationary conditions have been investigated in a total of 76 volunteers (34 females, 42 males) who participated in the study. Inclusion criteria incorporated driving a Saab 9–3 on a regularly basis. Results: The majority of the volunteers (89%) adjusted the head restraint to any of the 3 uppermost positions and as many as 59% in the top position. The average vertical distance between the top of the head and the top of the head restraint (offset) increase linearly with increasing statures, from an average of −26 mm (head below the head restraint) for small females to an average of 82 mm (head above the head restraint) for large males. On average, the offset was 23 mm for females, which is within a satisfactory range and in accordance with recommendations; the corresponding value for males was 72 mm. The backset tended to be shorter among female volunteers (on average 27 mm) compared to the male volunteers (on average 44 mm). Moreover, the backset tended to increase with increasing statures. Conclusions: Incorrect adjustment of the head restraint cannot explain the large differences found between the sexes in the effectiveness of the SAHR system.

The objective of this study was 2-fold: first, to compare Euro NCAP safety ratings of cars with those published by the Folksam real-world injury ratings; and second, to compare injury risk measures between Euro NCAP 2 and 5 Star cars with real-world injury and disability outcomes using police and insurance injury data.Car models were grouped according to the Euro NCAP star rating scores. Folksam risk of injury ratings come from statistical analysis of real-world crashes using police and insurance databases. The paired comparison method using 2-car crashes was used to control for crash speed and the mass differences between cars of different weights were normalized.For all comparisons, 5-star rated Euro NCAP cars were found to have a lower risk of injury compared to 2-star rated cars (5-star cars were 10% ± 2.5% lower risk than 2-star cars). For fatal and serious injuries, the difference was 23 ± 8 percent, and for fatal injuries alone the difference was 68 ± 32 percent. By comparison, the Folksam 5-star rated cars had a relative risk of 0.020 ± 0.0024, whereas 2-star rated car risk was 0.028 ± 0.0016, corresponding to a 27 percent difference in risk between 5- and 2-star cars.Good correlation was found between Euro NCAP test results and real-world injury outcomes. The largest difference in injury risk between 2- and 5-star rated cars in Euro NCAP was found for risk of fatality, confirming that car manufacturers have focused their safety performance on serious crash outcomes. In addition, Euro NCAP crash tests were shown to be highly correlated with serious crash performance, confirming their relevance for evaluating real-world crash performance. Good concordance was found between Euro NCAP and Folksam real-world crash and injury ratings.

The objective in this study of crashed cars fitted with on-board crash pulse recorders (CPR) was to present differences in average crash severity and distribution of crash severity, depending on collision partner. The investigation included both frontal and rear-end two-vehicle and single-vehicle crashes, into deformable and rigid roadside objects. In total, 544 real-world crashes involving cars fitted with CPRs were included. A difference in average crash severity was found in crashes with different collision partners. Frontal two-vehicle and single-vehicle crashes with rigid roadside objects were shown to generate the highest crash severity. In 22% of crashes with heavy goods vehicles (HGVs) and 2% of car-to-car crashes, change of velocity exceeded 45 km/h. These differences indicate the importance of focusing on compatibility. There was a statistically significant difference between frontal two-vehicle and single-vehicle crashes with deformable objects, and also between single-vehicle crashes with deformable objects and single-vehicle crashes with rigid roadside objects. Of these, the least harmful crash type was single-vehicle crashes into deformable objects. This study provides further insight into how collision partners or objects influence change of velocity and mean acceleration in the studied vehicles. Furthermore, it illustrates the importance of paying attention to compatibility issues, regarding aspects influencing both change of velocity and acceleration.

© 2016 Taylor & Francis Group, LLC. Objective: Several studies have reported the benefits of motorcycle antilock braking systems (ABS) in reducing injury crashes, due to improved stability and braking performance. Both aspects may prevent crashes but may also reduce the crash severity when a collision occurs. However, it is still unknown to what extent the reductions in injury crashes with ABS may be due to a combination of these mechanisms. Methods: Swedish hospital and police reports (2003–2012) were used. The risk for permanent medical impairment (RPMI) was calculated, showing the risk of at least 1 or 10% permanent medical impairment. In total, 165 crashes involving ABS-equipped motorcycles were compared with 500 crashes with similar motorcycles without ABS. The analysis was performed in 3 steps. First, the reduction in emergency care visits with ABS was calculated using an induced exposure approach. Secondly, the injury mitigating effects of ABS were investigated. The mean RPMI 1+ and RPMI 10+ were analyzed for different crash types. The distributions of impairing injuries (PMI 1+) and severely impairing injuries (PMI 10+) were also analyzed. In the third step, the total reduction of PMI 1+ and PMI 10+ injured motorcyclists was calculated by combining the reductions found in the previous steps. An additional analysis of combined braking systems (CBS) together with ABS was also performed. Results: The results showed that emergency care visits were reduced by 47% with ABS. In the second step, it was found that the mean RPMI 1+ and RPMI 10+ with ABS were 15 and 37% lower, respectively. Finally, the third step showed that the total reductions in terms of crash avoidance and mitigation of PMI 1+ and PMI 10+ injured motorcyclists with ABS were 67 and 55%, respectively. However, PMI 1+ and PMI 10+ leg injuries were not reduced by ABS to the same extent. Indications were found suggesting that the benefits of ABS together with CBS may be greater than ABS alone. Conclusions: This article indicated that motorcycle ABS reduced impairing injuries, mostly due to fewer emergency care visits but also due to a reduction in crash severity. This may seem reasonable as the improved stability and braking performance provided by ABS could prevent some crashes but would also decrease crash severity if a collision still occurs. As suggested by previous studies, however, the lower extremities would be more exposed in a crash with ABS. It is recommended that future research should follow up these results with additional data.

Objective: There is limited knowledge of the long-term medical consequences for occupants injured in car crashes in various impact directions. Thus, the objective was to evaluate whether injuries leading to permanent medical impairment differ depending on impact direction.Methods: In total, 36,743 injured occupants in car crashes that occurred between 1995 and 2011 were included. All initial injuries (n = 61,440) were classified according to the Abbreviated Injury Scale (AIS) 2005. Injured car occupants were followed for at least 3 years to assess permanent medical impairment. The data were divided into different groups according to impact direction and levels of permanent impairment. The risk of permanent medical impairment was established for different body regions and injury severity levels, according to AIS.Results: It was found that almost 12% of all car occupants sustained a permanent medical impairment. Given an injury, car occupants involved in rollover crashes had the highest overall risk to sustain a permanent medical impairment. Half of the head injuries leading to long-term consequences occurred in frontal impacts. Far-side occupants had almost the same risk as near-side occupants. Occupants who sustained a permanent medical impairment from cervical spine injuries had similar risk in all impact directions (13%) except from rollover (17%). However, these injuries occurred more often in rear crashes. Most of the injuries leading to long-term consequences were classified as minor injuries by AIS for all impact directions.Conclusions: Studying crash data from a perspective of medical impairment is important to identify injuries that might not be prioritized only considering the AIS but might lead to lower quality of life for the occupant and also costs for society. These results can be used for road transport system strategies and for making priority decisions in vehicle design.

Objective: As fatalities from car crashes decrease, focus on medical impairment following car crashes becomes more essential. This study assessed the risk of permanent medical impairment based on car occupant injuries. The aim was to study whether the risk of permanent medical impairment differs depending on age and gender.Methods: In total, 36,744 injured occupants in car crashes that occurred between 1995 and 2010 were included. All initial injuries (n = 61,440) were classified according to the Abbreviated Injury Scale (AIS) 2005. If a car occupant still had residual symptoms 3 years after a crash, the case was classed as a permanent medical impairment. In total, 5,144 injuries led to permanent medical impairment. The data were divided into different groups according to age and gender as well as levels of permanent impairment. The risk of permanent medical impairment was established for different body regions and injury severity levels, according to the AIS.Results: The cervical spine was the body region that had the highest number of diagnoses, and occupants who sustained injuries to the upper and lower extremities had the highest risk of medical impairment for both genders. Females aged 60 and above had a higher risk of permanent medical impairment from fractures in the extremities compared to males in the same age group and younger females. Females aged 44 or younger had a higher risk of permanent medical impairment from whiplash-associated disorders (WAD) than males in the same age group. Minor and moderate injuries (AIS 1–2) had a higher risk of permanent medical impairment among older car occupants compared to younger ones.Conclusions: Differences in long-term outcome were dependent on both gender and age. Differences between age groups were generally greater than between genders. The vast majority of permanent medical impairments resulted from diagnoses with a low risk of fatality. The results emphasize the impact of age and gender in long-term consequences from car crashes. They could be used when designing safety technology in cars as well as to improve health care by contributing to better allocation of rehabilitation resources following trauma.

Objectives: This study set out to evaluate the effectiveness of motorcycle antilock braking systems (ABS) in reducing real-life crashes.Since the European Parliament has voted on legislation making ABS mandatory on all new motorcycles over 125 cc from 2016, the fitment rate in Europe is likely to increase in the coming years. Though previous research has focused on mostly large displacement motorcycles, this study used police reports from Spain (2006–2009), Italy (2009), and Sweden (2003–2012) in order to analyze a wide range of motorcycles, including scooters, and compare countries with different motorcycling habits.Methods: The statistical analysis used odds ratio calculations with an induced exposure approach. Previous research found that head-on crashes were the least ABS-affected crash type and was therefore used as the nonsensitive crash type for ABS in these calculations. The same motorcycle models, with and without ABS, were compared and the calculations were carried out for each country separately. Crashes involving only scooters were further analyzed.Results: The effectiveness of motorcycle ABS in reducing injury crashes ranged from 24% (95% confidence interval [CI], 12–36) in Italy to 29% (95% CI, 20–38) in Spain, and 34% (95% CI, 16–52) in Sweden. The reductions in severe and fatal crashes were even greater, at 34% (95% CI, 24–44) in Spain and 42% (95% CI, 23–61) in Sweden.The overall reductions of crashes involving ABS-equipped scooters (at least 250 cc) were 27% (95% CI, 12–42) in Italy and 22% (95% CI, 2–42) in Spain. ABS on scooters with at least a 250 cc engine reduced severe and fatal crashes by 31% (95% CI, 12–50), based on Spanish data alone.Conclusions: At this stage, there is more than sufficient scientific-based evidence to support the implementation of ABS on all motorcycles, even light ones. Further research should aim at understanding the injury mitigating effects of motorcycle ABS, possibly in combination with combined braking systems.

Recently, smart seat belt reminders (SBR) have been introduced in cars. By increasingly reminding drivers and passengers if they are not using the seat belt, the intention is to increase the belt use to almost 100%. Objective. The objective was to study if there were differences in driver's seat belt use between cars with and without SBR. Methods. Drivers of cars with and without SBR were observed concerning seat belt use. The case (cars with SBR) and the control group (cars without SBR) were similar in all major aspects except SBR. In all, more than 3,000 drivers were observed in five cities in Sweden. Results. In cars without SBR, 82.3 percent of the drivers used the seat belt, while in cars with SBR, the seat belt use was 98.9 percent. The difference was significant. In cars with mild reminders, the use was 93.0 percent. Conclusion. It is concluded, that if the results can be generalised to the whole car population this would have a dramatic impact on the number of fatally and seriously injured car occ...

Electronic Stability Control (ESC) was introduced on the mass market in 1998. Since then, several studies showing the positive effects of ESC have been presented.In this study, data from crashes occurring in Sweden during 1998 to 2004 were used to evaluate the effectiveness of ESC on real life crashes. The effectiveness was analyzed for different road conditions, and some accident types and injury levels.The study used statistical analysis. To control for exposure, induced exposure methods were used, where ESC-sensitive to ESC-insensitive crashes and road conditions were matched in relation to cars equipped with and without ESC. Cars of similar or, in some cases, identical make and model were used to isolate the role of ESC.The study shows a positive and consistent effect of ESC overall and in circumstances where the road has low friction. The overall effectiveness on all injury crash types, except rear end crashes, was 16.7 +/- 9.3%, while for serious and fatal crashes; the effectiveness was 21.6 +/- 12.8%. The corresponding estimates for crashes with injured car occupants were 23.0 +/- 9.2% and 26.9 +/- 13.9%. For serious and fatal loss-of-control type crashes on wet roads the effectiveness was 56.2 +/- 23.5% and for roads covered with ice or snow the effectiveness was 49.2 +/- 30.2%. It was estimated that for Sweden, with a total of 500 vehicle related deaths annually, that 80-100 fatalities could be saved annually if all cars had ESC.ESC was found to reduce crashes with personal injuries, especially serious and fatal injuries. The effectiveness ranged from at least 13% for car occupants in all types of crashes with serious or fatal outcome to a minimum of 35% effectiveness for single/oncoming/overtaking serious and fatal crashes on wet or icy road surface. No difference in deformation pattern was found for cars with or without ESC.

Validated injury criteria are essential when developing restraints for AIS 1 neck injuries, which should protect occupants in a variety of crash situations. Such criteria have been proposed and attempts have been made to validate or disprove these. However, no criterion has yet been fully validated. The objective of this study is to evaluate the influence of seat geometry and seating posture on the NIC(max) long-term AIS 1 neck injury predictability by making parameter analyses on reconstructed real-life rear-end crashes with known injury outcomes.Mathematical models of the BioRID II and three car seats were used to reconstruct 79 rear-end crashes involving 110 occupants with known injury outcomes. Correlations between the NIC(max) values and the duration of AIS 1 neck injuries were evaluated for variations in seat geometry and seating posture. Sensitivities, specificities, positive predictive values, and negative predictive values were also calculated to evaluate the NIC(max) predictability.Correlations between the NIC(max) values and the duration of AIS 1 neck injuries were found and these relations were used to establish injury risk curves for variations in seat geometry and seating posture. Sensitivities, specificities, positive predictive values, and negative predictive values showed that the NIC(max) predicts long-term AIS 1 neck injuries also for variations in seat geometry and seating postures.The NIC(max) can be used to predict long-term AIS 1 neck injuries.

Objective: The study examines whether socioeconomic and sex differences in road-traffic crashes leading to injury vary according to car-safety level. Method: Individuals records of subjects born 1970-1972 registered in the Swedish Census of 1985 (n = 334,070) are linked to road-traffic-crash data for the period 1988A¢??2000 for first police-registered two-car crashes leading to severe or fatal injury (n = 4875). Injuries are split into categories according to level of car safety on a five-point scale, based on criteria related to crash safety. Account is taken of both how the car is constructed and the effectiveness of its safety equipment (such as airbags and seat belts). For each car-safety level, relative risks are computed considering socioeconomic groups of origin, educational level, and sex. Results: No substantial differences between drivers in different socioeconomic positions of origin is observed except for crashes involving cars 30% better than average with regard to safety. There are consistent risk differences across all car-safety categories according to educational level. Male drivers show an elevated risk of injury in all car categories, except for cars with the poorest safety where they are at significant under-risk. Conclusions: Car-safety level impacts on social differences in road-traffic injury risks in specific and restricted manners. Car-safety development is an important factor in improved road safety, but it may not benefit all to the same extent.

ESP (Electronic Stability Program) has recently been introduced onto the market in an effort to reduce the number and severity of loss-of-control automobile accidents. This reduction is expected to be particularly evident for accidents on roads with low friction (e.g., wet or icy conditions). This study aimed to evaluate the statistical effectiveness of ESP using data from accidents that occurred in Sweden during 2000 to 2002. To control for exposure, induced exposure methods were used, where ESP-sensitive to ESP-insensitive accidents and road conditions were matched in relation to cars equipped with and without ESP. Cars of similar, or in some cases identical, make and model were used to isolate the role of ESP. As predicted, the study showed a positive effect of ESP in circumstances where road surfaces have low friction. The overall effectiveness was 22.1 (+/-21) percent, while for accidents on wet roads, the effectiveness increased to 31.5 (+/-23.4) percent. On roads covered with ice and snow, the corresponding effectiveness was 38.2 (+/-26.1) percent. In addition, ESP was found to be effective for three different types of cars: small front-wheel drive; large front-wheel drive; and large rear-wheel drive.

There are variations in rear impacts causing Whiplash Associated Disorders (WADs) which lead to short- and long-term consequences. Most rear impacts lead to no injury or to symptoms that are temporary. Impacts where the duration of symptoms differs need to be separated in analyses in order to isolate representative rear impact conditions in which more long-lasting WADs occur. The correlation between injury risk and impact severity parameters based on acceleration levels is largely unknown. Since 1995, approximately 40,000 vehicles on the Swedish market have been equipped with crash pulse recorders measuring the acceleration time history in rear impacts. In the present study, the results from crash recording of 66 real-life rear impacts were analyzed, where the change of velocity and the crash pulse were measured. The injury status of 94 front-seat occupants was classified as: no injury, symptoms for less than one month, symptoms for more than one month, or symptoms for more than six months after the impac...

Several parameters based on acceleration levels, such as mean or peak acceleration, may correlate with injury risk, or may together with change of velocity, explain the risk of injury, and thus may form the risk function for different kind of injuries. The aim was to study the influence on injury risk for mean and peak acceleration and change of velocity as well as how these correlate with each other. The results from 144 crash pulse recorders and the diagnoses from driver injuries in real life frontal impacts were analyzed. Change of velocity and mean and peak acceleration were calculated from each recorded crash pulse. The results and conclusion were that mean and peak accelerations influence the injury risk, and high mean or peak acceleration may lead to severe injuries. Mean and peak accelerations together may explain the risk of injury in the studied impacts. When these parameters were combined, a limit could be drawn, above which there was an 89% risk of receiving a moderate or severe injury, while the risk was only 5.5% below that line. The different combinations of impact severity parameters shown in this study are helpful when crash pulses are created for crash tests and computer simulations.

This paper presents results from real life collisions, collected in a unique data collection system, where the crash pulse has been recorded in the impact phase. Since 1992, approximately 100,000 crash recorders have been installed in vehicles, and about 300 crash pulses have been recorded. A crash test is also presented involving two vehicles of different design and performance in narrow offset impacts. Narrow offset impacts or impacts with small overlap, are here defined as impacts with an overlap of less than 30%, which often result in glance-off. Severe narrow offset collisions are characterised by high closing velocity, a fairly low change of velocity, but major intrusion and high intrusion velocity. For most car models the main part of the energy absorbing frontal structure is not engaged in narrow offset impacts. Narrow offset impacts account for a large part of fatalities and severe injuries and has to be addressed to a higher extent. Existing standard crash tests do not address the performance of the vehicle construction in this type of impact. Results show that the percentage of moderately and severely injured drivers was higher in impacts with an overlap below 30% than in impacts with an overlap of more than 30%. It is also shown that the frontal structure is important for the performance in narrow offset impacts. The reconstructions of these collisions are discussed. Language: en

Knowledge of how crash severity influences injury risk in car crashes is essential in order to create a safe road transport system. Analyses of real-world crashes increase the ability to obtain such knowledge.The aim of this study was to present injury risk functions based on real-world frontal crashes where crash severity was measured with on-board crash pulse recorders.Results from 489 frontal car crashes (26 models of four car makes) with recorded acceleration-time history were analysed. Injury risk functions for restrained front seat occupants were generated for maximum AIS value of two or greater (MAIS2+) using multiple logistic regression. Analytical as well as empirical injury risk was plotted for several crash severity parameters; change of velocity, mean acceleration and peak acceleration. In addition to crash severity, the influence of occupant age and gender was investigated.A strong dependence between injury risk and crash severity was found. The risk curves reflect that small changes in crash severity may have a considerable influence on the risk of injury. Mean acceleration, followed by change of velocity, was found to be the single variable that best explained the risk of being injured (MAIS2+) in a crash. Furthermore, all three crash severity parameters were found to predict injury better than age and gender. However, age was an important factor. The very best model describing MAIS2+ injury risk included delta V supplemented by an interaction term of peak acceleration and age.

Vehicle deformations are important sources for information about the performance of safety systems. Photogrammetry has developed vastly under recent years. In this study modern photogrammetrical methods have been used for vehicle deformation analysis. The study describes the equipment for documentation and recording in the field (semi-metric camera), and a system for photogrammetrical measurements of the images in laboratory environment (personal computer and digitizing tablet). The material used is approximately 500 collected and measured cases. The study shows that the reliability is high and that accuracies around 15mm can be achieved even if the equipment and routines used are relatively simple. The effects of further development using video cameras for data capture and digital images for measurements are discussed.

The aim of this study was to aid the optimisation of future, vehicle based, pedestrian injury countermeasures. The German In-Depth Accident Study (GIDAS) database was queried for pedestrians impacted by the front of a passenger car or van. A total of 1030 cases from 1998 to 2008 were studied including 161 severely (AIS3+) injured pedestrians. Considering the severe injuries, the most frequent injury mechanisms were "leg-to-front end", "head-to-windscreen area", "chest-to-bonnet area", and "chest-to-windscreen area". For children, a "head-to-bonnet area" impact was the second most common source of injury. With safety systems targeting these five injury mechanisms, 73% (95% confidence interval [CI], 65-81%) of the severely injured pedestrians would be provided protection from all of their vehicle-induced severe injuries. Omitting the windscreen area, this figure is decreased to 44% (CI, 36-53%). Furthermore, 31% of the surviving pedestrians were estimated to sustain a permanent medical impairment at any level. For more severe impairment, head was the dominating body region. The study shows that when developing countermeasures for the windscreen area to mitigate head injuries, attention should be paid to the structural parts of the windscreen area with a special focus on brain injuries. Finally, the incidence and risk of severe injury were derived as functions of impact speed for different body regions and injury sources.

In addition to investigating risk of death due to road traffic injuries, there is a need to better describe the risk of serious consequences. This study assessed risk of permanent medical impairment based on road traffic injuries classified according to AIS-2005. Injured car occupants were followed for at least 5 years to assess permanent medical impairment. After an initial injury, the risk of permanent impairment was established for injuries to different body regions and AIS levels. Degree of impairment was assessed according to a manual used by all Swedish insurance companies. Those included in the study were 20,484 car occupants injured in crashes that occurred between 1995 and 2001. Three risk levels of sustaining a permanent medical impairment (RPMI) were made. It was concluded that almost 10% of all car occupants with AIS1 injuries sustained a permanent medical impairment. It is therefore important to include minor injuries leading to impairment when measuring loss of health due to road traffic crashes. Furthermore the highest risk of sustaining a permanent medical impairment from an AIS1 injury was associated with injuries to the cervical spine and upper and lower extremities. One third of AIS3 head and cervical spine injuries led to the highest RPMI level of impairment. Injuries to the thorax and abdomen gave the lowest risk of permanent medical impairment on all AIS levels and all impairment levels. The result can be used for road transport system strategies, and for making priority decisions in vehicle design.

Many modern cars have seat belt reminders (SBRs) using loud and clear sound and light signals. These systems have developed over the last few years. This study investigates how these modern systems influence the seat belt use in real-life traffic in built-up areas in some European cities.The data were collected by field observations in major cities in six European countries and in five cities around Sweden. A selection of car models having seat belt reminders (SBR) were compared to a fleet of similar car models without such reminders.A significant difference in seat belt wearing rate was found in the cars with seat belt reminders. For all observations, the total seat belt wearing rate was 97.5% +/- 0.5% in cars with SBR, while it was 85.8% +/- 0.8% in cars without. There were differences in seat belt use in the different observation locations. The lowest seat belt use was found in Brussels/Belgium with a use rate of 92.6 +/- 2.2% in cars with seat belt reminders and 69.6 +/- 3.1% in cars not fitted with reminders. The highest seat belt use was found in Paris/France where 99.8 +/- 0.4% of the drivers used the seat belt in cars with reminders and 96.9 +/-1.1% were belted in cars without reminders.Seat belt reminders fulfilling Euro NCAP's seat belt reminder protocol are increasing the seat belt use in daily traffic significantly. Around 80% (82.2% +/- 8.6%) of the drivers not putting the belt on without a seat belt reminder do so in cars equipped with an SBR that has a light signal and an associated loud and clear sound signal.

Estimating vehicle collision severity is a key factor in biomechanics as it allows correlation of injuries with impact severity in real accidents. Key vehicle parameters for injury are the mean, peak and shape of the acceleration pulse. Real world frontal collision patterns reflect the distributions of overlap, impact angle, vehicle compliance and car-to-car frontal structural interactions. In this paper, a model relating displacement to crush as a function of overlap is combined with a full-width barrier characteristic to predict the acceleration-displacement response for given car types. Application yields predictions for 30 degree angled barrier and 45% overlap rigid barrier tests which closely match the corresponding experimental results. Separately, regression analysis of data from onboard collision recorders of real world collisions for 16 car types in 269 collisions yielded relationships between mean acceleration, velocity change and displacement for individual car types. This shows that the mean crumpling stress/density is equivalent to the normalised mean acceleration and is independent of size or mass. The geometric crush model combined with a single full-width barrier characteristic for the car population is used to model the variability of structural characteristics in frontal collisions. These are combined with overlap and crush profile distributions to predict overall collision characteristics using Monte Carlo methods. The results confirm that the collision recorders data reflects the distribution of frontal collisions. A new method of estimating the frontal response of individual cars at various overlaps from a single full-width barrier test is presented, with predictions that correlate closely with collision recorder data.

There is continuing controversy regarding the role of car mass in occupant — risk. Injury risk is influenced not only by the vehicle deformation characteristics and the occupant restraint system, but also by the size and mass of both case and partner cars. Recent research has shown that injury is better correlated with mean car acceleration than with velocity change. Injury risk relations for belted/unbelted drivers in all crashes with AIS 3+ and fatal injuries were derived from US data using a modified Joksch [7] type risk equation. These risk equations are shown to compare with recent Swedish AIS 2+ and AIS 3+ frontal collision data and with US frontal collision fatality data. The derived AIS 3+ and fatality risk functions, in conjunction with car population stress/density characteristics, were combined with US, German and Japanese car mass and collision velocity distributions to predict the variation in fatality and AIS 3+ injury risk with car mass and mass ratio using Monte Carlo simulation techniques. The resulting predictions were compared to published real world accident risk versus car mass data for each country, and a high degree of correspondence obtained. The results show that empirically derived car population structural characteristics and injury risk functions satisfactorily explain the real world fatality and injury versus mass effect.

One hundred ninety-five rear impacts with both front- and rear-seat occupants in the struck car, where at least one occupant sustained permanent disability, were selected for study. There was a significantly higher disability risk for the female rear-seat occupant compared with the male driver. Furthermore, a higher risk was found for female rear-seat occupants compared with female front-seat passengers. The disability risk for occupants of the driver's seat was three times higher for females than for males, and four times higher for females in the rear seat. In the future, test methods should consider the risk of whiplash injury in both the front and the rear seat.

AIS1 neck injuries are the most frequent disabling injuries among car occupants in road traffic accidents. Although neck injury is mostly regarded as resulting from rear end collisions, almost one third of all neck injuries occur in frontal impacts. The injury mechanisms in both rear-end and frontal impacts are still not known, although different hypotheses exist. Since 1992, approx. 100,000 vehicles on the Swedish market have been equipped with crash recorders to measuring frontal impacts. This paper analyses the influence of different characteristics derived from the acceleration time history on the risk of short- and long-term disability to the neck in frontal impacts. The study includes injury outcomes from 187 restrained front seat occupants in 143 frontal collisions with an overlap exceeding 25%, where the crash pulses have been recorded using crash pulse recorders. The results show that the shape of the crash pulse influences the risk of long-term disability to the neck. The vehicle accelerations in the mid and last third of the crash pulse seem to be important. It is also shown how change of velocity and mean and peak accelerations influence the neck-injury risk. It is suggested that the risk of sustaining an AIS1 neck injury in frontal impacts could be reduced by using more effective pretensioners and more advanced belt-load limiters. These results may also have implications for neck injury mechanisms in rear-end impacts.

The main public-health problem concerning WAD are injuries leading to long-term consequences. Yet epidemiological studies mostly concentrate on data based on the injury outcome occurring shortly after the crash. The purpose of this article is to study the influence of crash severity in rear impacts leading to short and long-term consequences to the neck (WAD 1-3), lasting less than or more than 1 year. The influence of change of velocity as well as the car acceleration were investigated by using data from crash pulse recorders (CPR) installed in vehicles, involved in rear impacts. The influence of the car acceleration were also investigated by studying the frequency of occurrence of a tow-bar (hinge) on the struck car. Apart from real-life data, full-scale car-to-car crashes were performed to evaluate the influence of a tow-bar on the struck car. The crash tests showed that a tow-bar may significantly affect the acceleration of the car as well as that of the occupant. According to real-life crashes, a tow-bar on the struck car increased the risk of long-term consequences by 22% but did not affect the risk of short-term consequences. Out of the 28 crash recorder-equipped struck cars involving 38 occupants, 15 sustained no injury where the peak acceleration was 6g or less, 20 sustained short-term consequences where the peak acceleration was 10g or less. Three occupants from two different crashes sustained long-term consequences. The two crashes which resulted in long-term disabling neck injuries had the highest peak acceleration (15 and 13 x g), but not the highest change of velocity.

Estimation of the accident severity is a fundamental requirement in accident reconstruction and analysis. Accident severity can be measured in many different ways, but in frontal collisions change of velocity, energy equivalent speed or equivalent barrier speed are frequently used parameters. These parameters are most often estimated from vehicle deformation. It is known, however, that the quality of these estimates is limited if compared with these obtained in laboratory test conditions. To be able to achieve almost the same measurements and measurement accuracy in real-life accidents as in the laboratory, where the acceleration time history is measured, an on-board measurement technique is required. This presentation gives results of tests of a low cost device for measuring the crash pulse for a car involved in an accident, concerning systematic and random error. The device, called the Crash Pulse Recorder (CPR), has been tested previously in several sled tests. The CPR is based on measurement of the movement of the mass in a spring mass system in a collision. A brief description of its construction is also included. The CPR is an integral part of a large accident data collection system including interior and exterior deformation measurements and evaluation of injury outcome. This report presents the results of several full-scale crash tests, undertaken to evaluate the accuracy and precision of the CPR in cars in different impact modes. The tests comprised both offset and angled collisions. Most of the tests were car to car collisions, but barrier tests were also performed. The random error of the CPR was found to be 2.2 km/hr for the delta V measurements and 0.6 g for mean acceleration.

In the design of a safe road transport system there is a need to better understand the safety challenges lying ahead. One way of doing that is to evaluate safety technology with retrospective analysis of crashes. However, by using retros- pective data there is the risk of adapting safety innovations to scenarios irrelevant in the future. Also, challenges arise as safety interventions do not act alone but are rather interacting components in a complex road transport system. The objective of this study was therefore to facilitate the prioritizing of road safety measures by developing and applying a new method to consider possible impact of future vehicle safety technology. The key point was to project the chain of events leading to a crash today into the crashes for a given time in the future. Assumptions on implementation on safety technologies were made and these assump- tions were applied on the crashes of today. It was estimated which crashes would be prevented and the residual was analyzed to identify the characteristics of future crashes. The Swedish Transport Administration's in-depth studies of fatal crashes from 2010 involving car passengers (n=156) were used. This study estimated that the number of killed car occupant would be reduced with 53 percent from the year 2010 to 2020. Through this new method, valuable information regarding the characteristic of the future crashes was found. The results of this study showed that it was possible to evaluate future impact of vehicle safety technology if detailed and representative crash data is available.

Pedestrians and bicyclists account for a significant share of deaths and serious injuries in the road transport system. The protection of pedestrians in car-to-pedestrian crashes has therefore been addressed by friendlier car fronts and since 1997, the European New Car Assessment Program (Euro NCAP) has assessed the level of protection for most car models available in Europe. In the current study, Euro NCAP pedestrian scoring was compared with real-life injury outcomes in car-to-pedestrian and car-to-bicyclist crashes occurring in Sweden. Approximately 1200 injured pedestrians and 2000 injured bicyclists were included in the study. Groups of cars with low, medium and high pedestrian scores were compared with respect to pedestrian injury severity on the Maximum Abbreviated Injury Scale (MAIS)-level and risk of permanent medical impairment (RPMI). Significant injury reductions to both pedestrians and bicyclists were found between low and high performing cars. For pedestrians, the reduction of MAIS2+, MAIS3+, RPMI1+ and RPMI10+ ranged from 20-56% and was significant on all levels except for MAIS3+ injuries. Pedestrian head injuries had the highest reduction, 80-90% depending on level of medical impairment. For bicyclist, an injury reduction was only observed between medium and high performing cars. Significant injury reductions were found for all body regions. It was also found that cars fitted with autonomous emergency braking including pedestrian detection might have a 60-70% lower crash involvement than expected. Based on these results, it was recommended that pedestrian protection are implemented on a global scale to provide protection for vulnerable road users worldwide.