Heavy quadricycles are gaining traction as sustainable urban mobility solutions due to their compact design, energy efficiency, and reduced environmental impact. However, their lightweight structure and limited safety features pose significant challenges in collisions, particularly with heavier traditional passenger cars. This study investigates the safety implications of introducing heavy quadricycles (L6e and L7e categories) into the circulating fleet, focusing on collision dynamics and occupant Injury Risk (IR). Advanced simulation tools are employed to reconstruct real-world impacts from an in-depth accident database and analyse the consequences of substituting traditional cars with L-category quadricycles. Velocity change (ΔV) and IR are determined across various collision scenarios as a function of market penetration. Results indicate that in high-speed scenarios (90 km/h) L-category quadricycles experience substantially higher ΔV compared to traditional cars in similar collisions, leading to increased occupant loads and IR across the investigated collision scenarios. Conversely, in 50 km/h urban zones, the average fleet IR decreases, with ΔV averaging 12.6 km/h at 50% penetration. The safest environment is observed in 30 km/h cities, where IR decreases by over 50%. The findings suggest that current consumer programme tests may not fully capture certain critical collision scenarios for L-category quadricycles, notably side impacts. Consequently, further attention should be directed towards safety assessment protocols and design refinements that enhance crashworthiness without compromising the fundamental vehicle concept. The study concludes that while L-category quadricycles offer benefits for sustainable urban transportation, their integration requires careful management to address safety concerns, particularly in high-speed environments.

The aim of this study was to investigate the difference in rear impact dynamic response between a male and a female crash test dummy, in Saab 9–3 seats fitted with the Saab Active Head Restraint (SAHR) whiplash injury mitigation system. According to real world injury data, this SAHR system offers a greater risk reduction for the male population in comparison to the female. Identifying response differences between the male and female dummies, could explain the risk differences seen in real world crashes. Six sled tests were performed in Saab 9–3 seats (model year 1998–2002) in accordance with the European New Car Assessment Programme (Euro NCAP) whiplash test procedure (medium pulse, Δv 16 km/h, max acceleration 10 g). Two different low speed rear impact crash test dummies were used for the tests; the 50th percentile female prototype BioRID P50F_V2 and the 50th percentile male BioRID II. Both dummies exhibited early Head Restraint (HR) contact times which resulted in Neck Injury Criterion (NIC) values well below the recommended limit of 15 m2/s2. On the other hand, the NICprotraction values were almost two times greater for the female dummy in comparison to the male. In the Saab 9–3 seat, the SAHR system may cause a forward push to the head for average sized females, resulting in protraction of the neck rather than retraction. Current whiplash protection testing is performed with a 50th percentile male dummy. However, the results of this study show that in order to explain the sex differences found in real world data, it is necessary to use sex specific sizes of dummies developed for rear impact testing and include injury criteria to cover also flexion and protraction motion in the dynamic response. To cover the majority of the adult population, we recommend using the 50th percentile female and male dummies.

Objective: The aim of this study is to investigate the effectiveness of Automatic Emergency Braking (AEB) with detection of pedestrians and bicyclists in reducing car-to-pedestrian and car-to-bicyclists collisions and also injury mitigation in these collisions. Methods: The study analyses collision data from the Swedish Traffic Accident Data Acquisition (STRADA) encompassing road traffic accidents reported by the police and by emergency hospitals in Sweden. Crashes occurring between the years 2012 and 2022 and with cars from model years 2012 to 2022 were included in the dataset. Two statistical analyses were performed. To evaluate the crash reduction effect of AEB, odds ratio calculations with an induced exposure approach was conducted where the outcomes of sensitive and non-sensitive crashes were studied. The sensitive crashes were hit pedestrians and bicyclists, respectively. The non-sensitive crash type in both comparisons was struck vehicles in rear-end crashes. The collision reducing effect was analysed for various speed limits, lighting and visibility conditions. To evaluate whether AEB has a reducing effect on injury severity, relative differences in injury outcomes (both proportion of MAIS3+ and risk of permanent impairment, RPMI) of pedestrians and bicyclist was compared for hitting cars with and without AEB. Results: A total of 2 160 pedestrian collisions and 3 374 cyclist collisions were included, and the non-sensitive crashes consisted of 5 738 vehicles. The overall reduction in crash risk was approximately 20% (±10%) for vehicles equipped with AEB with pedestrian and/or bicycle detection. When analysed by lighting conditions, reductions in crash risk of just over 20% were observed in daylight for vehicles with AEB with pedestrian and/or bicycle detection. It appears to be a reduction also in darkness, although the reductions found of approximately 20% were not statistically significant. Reductions were observed for various weather conditions, except for cyclist crashes during rain, fog, and snowfall. A greater reduction in crash risk was noted on high-speed roads (60–120 km/h) for vehicles equipped with AEB for bicycle detection compared to low-speed roads (10–50 km/h). No similar difference was observed for AEB with pedestrian detection. Additionally, there was a greater reduction in crashes at intersections for vehicles with AEB for pedestrian detection and on roads for vehicles with AEB for bicycle detection. No difference in injury severity, both regarding proportion of MAIS3+ and RPMI, for both pedestrians and bicyclists was observed between collisions involving vehicles with and without AEB. Conclusions: This study confirms the significant potential of AEB systems in improving road safety for pedestrians and cyclists. However, their current effectiveness is too low to provide sufficient protection at today's speed limits and their expected potential and real-world performance differ a lot, which highlights the need for improvements. The study shows varying effectiveness of AEB systems in reducing crash risks under different lighting, weather, and speed conditions. Furthermore, no injury mitigating effect could be verified for cars with AEB for pedestrians and bicyclist possibly showing that either a crash was completely avoided, or the AEB system did not perform any braking. While avoiding crashes could be the prime objective for an AEB for vulnerable road users, braking that reduce injury severity despite there was a crash is of importance as well.

This was the first retrospective study to estimate the effect of increased pedestrian protection, autonomous emergency braking, and speed management to reduce serious injuries among pedestrians and bicyclists. More specifically, the aim was to estimate the injury mitigating effects of the following interventions: AEB with pedestrian and bicyclist detection, Euro NCAP pedestrian test score, active bonnet, traffic calming at pedestrian and bicycle crossings, and additionally, the combined effect of the above-mentioned treatments. The main source of data was the Swedish traffic data acquisition system (Strada), where information of road traffic crashes between passenger cars and pedestrians or bicyclists for the period 1 January 2003–31 December 2022 was obtained. Cars with optional fitment of AEB systems were identified, and the license registration number was used to access individual car equipment lists to identify whether the vehicle was equipped with AEB with pedestrian and/or cyclist detection. Information about traffic calming at pedestrian and bicycle crossings was obtained from the Swedish Transport Administration. The injury metric used was risk of permanent medical impairment (RPMI) of at least one percent and ten percent. RPMI captures the risk of long-term medical impairment based on a diagnosed injury location and Abbreviated Injury Severity (AIS) score. The relative difference between the mean values of RPMI (mRPMI1%+ and mRPMI10%+) was calculated and tested using an independent two sample t-test which was conducted for unequal sample sizes and variance. Although many results were found to be statistically non-significant, the following results were found to be significant at least at 90% level. Pedestrian mRPMI10%+ was reduced by 44% in speed zones ≤ 50 km/h comparing the group struck by cars equipped with AEB with pedestrian detection compared to the group struck by cars without the system. For cyclists, the mRPMI10%+ was reduced by 35% in speed zones ≤ 50 km/h. For crashes within ± 20 meters from a pedestrian or bicycle crossing, the AEB system reduced 60% of pedestrians mRPMI10%+ at crossings with good safety standard compared to crossings of poor safety standard. The comparison of cars with poor performance (1–9 points) in the NCAP pedestrian test and cars with a high score (28–36 points) showed that pedestrian mRPMI10%+ was reduced by 48% across all speed limits, and by 64% including only those aged ≤ 64 years. For bicyclists, a significant reduction of cyclist mRPMI10%+ was found comparing low scoring cars to high scoring cars in ≤ 30 km/h speed limit (-73%) and across all speed limits (-36%). Including only those aged ≤ 64 years, the reduction was 49%. For the active bonnet, a significant reduction of mRPMI1%+ by 24% was observed but given that the rate of helmet wearing was higher in the group struck by cars with active bonnet, this difference cannot be attributed to an effect of an active bonnet. The STA safety rating of pedestrian and bicycle crossings showed that overall pedestrian mRPMI1%+ was reduced by 15%, while cyclists mRPMI10%+ was reduced by 32% comparing crossings of high safety level to crossings of poor safety level. The analysis of combined interventions showed that the total reduction of pedestrians and cyclists mRPMI10%+ together was 69%, from 6.4% to 2%. This paper demonstrates that a road environment with adapted infrastructure and speed, combined with passenger car technologies that improve the safety for vulnerable road users, can create significant reductions of serious (long-term) injuries among pedestrians and bicyclists.

Objective The first automatic emergency braking (AEB) system was presented in 2003 and aimed to mitigate or reduce rear-end crashes. Since then, several AEB systems aimed to reduce other collision types have been introduced and studies have shown that they reduce crash risks. The aim with this study was to evaluate crash reductions of cars fitted with AEB systems with pedestrian detection and those with bicyclist detection. Methods The study is based on the Swedish Traffic Accident Data Acquisition that includes road traffic accidents reported by the police and by emergency hospitals. Crashes occurring between 2015 and 2020 and with cars from model years 2015 to 2020 were included. The statistical analysis used odds ratio calculations with an induced exposure approach where the outcomes of sensitive and nonsensitive crashes were studied. The sensitive crashes were hit pedestrians and bicyclists, respectively. The nonsensitive crash type in both comparisons was struck vehicles in rear-end crashes. Evaluations were also made for different light and weather conditions and for high and low speed roads. Results Seven hundred and twelve hit pedestrians and 1,105 hit bicyclists were included, and the nonsensitive crashes consisted of 1,978 vehicles. The overall reduction on crash risk for AEB with pedestrian detection was 8% (+/- 15%; ns) and for AEB with bicyclist detection it was 21% (+/- 17%). When separating for light conditions, no reduction in crash risk for AEB with pedestrian detection nor for AEB with bicyclist detection could be seen in darkness. However, in daylight and twilight conditions, AEB with pedestrian detection reduced pedestrian crash risk by 18% (+/- 19%; ns) and AEB with bicyclist detection reduced bicyclist crash risk by 23% (+/- 19%). No significant reductions could be seen when separating for weather conditions except for a 53% (+/- 31%) reduction for bicyclists in rain, fog, and snowfall. A larger reduction on high-speed roads (50-120 km/h) compared with low-speed roads (10-40 km/h) was also found. Conclusions AEB systems with bicyclist detection were found to reduce the numbers of hit bicyclists, especially in daylight and twilight conditions. In darkness, no reduction for hit pedestrians or bicyclists was found.

In line with the UN’s global goals on sustainability several initiatives are promoting walking. However, if effective interventions are not implemented an increased number of pedestrians will lead to more road casualties. It is important to take appropriate decisions on interventions to reach Vision Zero adopted by the Swedish Government. This study describes the characteristics of fatal crashes with pedestrians on Swedish roads and investigates the potential of different vehicle and road infrastructure interventions to save lives. The Swedish Transport Administration (STA) in-depth database of fatal crashes was used for a case-by-case investigation. Out of the 226 fatally injured pedestrians during 2011–2016 in Sweden the most common accident scenario was a vehicle hitting a pedestrian while crossing the road. Most crashes occurred in darkness on rural roads (63%), but for urban areas the majority (53%) occurred in daylight. In general, interventions related to vehicle speed were found to address a larger proportion of the studied pedestrian fatalities on urban roads compared to on rural roads, while separated pedestrian paths outside the carriageway were found to address a larger proportion on rural roads compared to on urban roads. The intervention with the largest total potential was pedestrian crossings with speed calming measures for the motor vehicles, which had the potential to address 36% of the identified fatalities. A reduced speed limit in combination with speed calming interventions had the potential to prevent 29% of the studied fatalities while separate pedestrian paths outside the carriageway had the potential to prevent approximately 15%. It was estimated that the vehicle safety technology with the highest potential was autonomous emergency braking with pedestrian detection for passenger cars. With this system available on all cars, 58% of the studied fatalities could potentially be prevented. Most (up to 93%) of the studied fatally injured pedestrians could potentially be saved with known vehicle safety and road infrastructural technologies. However, the analysis of the potential effect of interventions show that it will take a long time until the advanced and potentially effective vehicle safety technologies will be widely spread. This shows the importance of speeding up the implementation. A fast implementation of effective interventions in the road infrastructure is also necessary, preferably using a plan for prioritization. There are two main approaches of doing that, separating road user groups, or reducing vehicle speeds in areas with mixed rod user groups to survivable levels, which is recommended to be 30 km/h. There is a need to identify areas where most pedestrian accidents occur and then use the most effective interventions. The results of this study could be helpful in this process.

Large corporations are today expected or obliged to report on accidental deaths and serious injuries to employed or contracted employed as a part of reporting on sustainability and workplace safety. Data about road crashes are part of such events and are therefore, but not separately, collected and presented. In Europe, 40% to 60% of all work-related accidents resulting in death has been reported to be road traffic accidents. In 2020, the Stockholm Declaration urged all corporations to report on their safety footprint including their entire value chain. The aims of the present study were to use a new definition of safety footprint and to quantify those killed as employed and at work, and those killed in a crash where the other part was at work, as so called third parties, to transports for duty with employed drivers. The Swedish Transport Administration (STA) in-depth database of fatal crashes was used, that covers all fatalities classified as road traffic related and consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. All fatalities excluding suicides or those caused by sickness occurring during year 2019 were investigated (n = 214). 11% (23/214) of the fatalities occurred when the killed person was at work and 16 while commuting. 37% of the fatal accidents occurred when the killed road user or the other part was at work. In total, almost half of the fatalities in the road transport system were related to work in some way when including both the fatally injured and their collision partners. A larger proportion of non-privately owned and procured vehicles was found for the vehicles of the collision partners compared to the vehicles of the fatally injured. In approximately one third of the fatal accidents a procurement of a transport service was involved. The Swedish Work Environment Authority (SWEA) identified 10 of the 23 fatalities at work investigated and none of these accidents was found to be investigated by the police as a crime related to the work environment. In conclusion, almost half of the fatalities in the road transport system in 2019 were related to work in some way, either the fatally injured or their collision partners were at work or while commuting. When including the third-party casualties, the problem becomes much bigger and more complex. In Sweden fatalities related to work are underreported, as the SWEA does not receive basic data. Efforts are needed to improve reporting of work-related road fatalities. It was found that the police did not investigate road traffic fatalities as death at workplace. It is crucial that the police start to follow the intention of regulations linked to workplace safety. If not, the possibility to collect relevant data for organizations to report on their safety footprint is limited. It is complicated to collect, classify and analyse value chain fatal crash information, mainly due to that the police do not investigate fatal road crashes as possibly work-related events. It is recommended that organizations manage their own data collection if they wish to report on their safety footprint data.

AbstractThis 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: 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.

This study aimed to evaluate developments in car crash safety in cars launched since the 1980s based on real-world crashes occurring years 2000–2019, with focus on the number of injuries leading to permanent medical impairment to different body regions, separated for gender and age. Police-reported two-car crashes were used to calculate relative risk of any injury, fatal and serious injury and fatality, and together with occupant injuries reported by Swedish emergency care centres the risk for permanent medical impairment was assessed. The cars were categorised in ten-year periods according to year of introduction. It was found that vehicle crashworthiness has improved steadily since the 1980s, with largest improvements for serious and fatal injuries and for injuries leading to PMI. Females were found to have higher injury risk for all types of injury severity studied (except for fatal injuries). The risk for serious and fatal injuries and fatal injuries alone was higher for occupants older than 50 years of age compared to those younger than 50. For male occupants, as well as for occupants younger than 50 years, the risk for injury leading to PMI to the cervical spine was found to increase in modern cars. Older occupants were also found to have an increased risk for injuries to the thoracic and lumbar spine.

Objective 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).Methods 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.Results 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.Conclusions 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.

Developments in car crash safety is preferably demonstrated by analyzing results from real-world crashes. Also results from crash tests can be used to show improvements in crash performance. Previous research has shown a positive development regarding safety performance. Studies from the early 2000 have shown that the European New Car Assessment Programme (Euro NCAP) consumer tests seem to predict the outcome in real-world crashes, although they consider only a part of all accident scenarios. In 2009 Euro NCAP added rear-end crash tests to the test protocol and since 2012 Euro NCAP has gradually further revised the rating protocol. It is therefore important to study developments in crash safety, and to evaluate how Euro NCAP test results correlate with real-world performance. This study aimed to show developments in car crash safety in cars launched since the 1980s based on real-world data, and to present how Euro NCAP crash test results predict the outcome in real-world crashes. Two-car crashes reported by the police (n=202 360) and occupant injuries reported by emergency care centers (n=57 863) to the Swedish Traffic Accident Data Acquisition database (STRADA) were analyzed. The cars were categorized in 5-year periods, according to the year of introduction. Developments were studied in terms of risk of any injury, risk of serious injury, risk of fatality, and risk of permanent medical impairment (PMI). Correlations with Euro NCAP test results were evaluated based on star levels for all categories of injury severity. It was found that vehicle crashworthiness has improved steadily over the years studied. The proportion of serious injuries was found to be reduced, as well as the injury risk for all injury severities studied. In a comparison of car models launched 1980-1984 with those launched 2015-2018 the proportion of AIS 3+ injuries was 67% lower. Furthermore, the risk for serious and fatal injury was 58% (+/-17%) lower, the risk for fatal injury was 88% (+/57%) lower, and the risk for PMI was 73% (+/-14%) lower. It was also shown that Euro NCAP crash test ratings mirror real world injury outcomes for all injury severities studied. Comparing 5-star with 2-star rated cars, the proportion of AIS 3+ injuries was 34% lower. Furthermore, the risk for serious and fatal injury was 22% (+/-4%) lower, the risk for fatal injury was 40% (+/-16%) lower, and the risk for PMI was 42% (+/-4%) lower. Large improvement in crash safety was found, especially regarding the risk for fatal injuries and injuries leading to PMI. Euro NCAP star ratings were found to well mirror the risk for fatal injuries and injuries leading to PMI. Consumer crash tests play an important role for the development in car safety. It is however important to continuously study how well these consumer tests predict the outcome in real-world crashes. Especially considering rating systems that reward the overall safety of a vehicle, such as the Euro NCAP.

The seat belt is one of the most effective ways to protect occupants in car crashes. Unfortunately, the average seat belt use in Europe (2018) was 83% for drivers and 81% for front seat passengers, where teenagers often have the lowest rate. The study aimed to use real-world car crashes to analyze the seat belt use among 0 to 18 year old children and teenagers as occupants and 18 to 20 year old drivers in Sweden 2011-2018. An additional aim was to analyze the effectiveness of seat belt reminders for both the front and the rear seats for the same age groups. The Swedish Traffic Accident Data Acquisition was used, which is the Swedish national system for road traffic injury data collection. The data included 26 270 car crashes involving 30 447 car occupants in passenger cars. Regarding passengers, 5% were children aged 0 to 18 years and 12% of the drivers were aged 18 to 20 years. Occupants aged 14 to 18 years had a lowest seat belt usage rate (89%), where the rate was even lower when these passengers had a young driver, 86% if the driver was aged 18 to 20 years and 93% if the driver was aged 30 years or above. And male passengers had a higher seat belt usage rate if they had a female driver, 94% if they had a female driver and 87% if they had a male driver. In the rear seat, children and teenagers aged 12 to 18 had a lowest seat belt usage rate and 18 year olds had the lowest (79%). The usage rate was lower when the passengers were sitting in the rear seat and when the driver was young. For children above 8 years, seat belt use was higher in cars with an SBR. This was also the case for adults (over 30 years). There was a clear difference for the rear seat, especially for teenagers 14 to 18 years, among whom 100% used the seat belt in a seat with an SBR. Young drivers had a higher risk to be involved in a road traffic accident compared to other age groups. Unfortunately, teenage passengers to these young drivers also have the lowest seat belt usage rate in the data. And there was indications that male teenage passengers have lower seat belt usage rate if their drivers also were male. One conclusion may be that the seat belt usage for a teenage passenger can depend on the driver. Therefore, it is important to put extra focus on this age group of drivers to increase seat belt use for their passengers The present study clearly shows the need of actions aimed to increasing the seat belt use for rear seat passengers. The seat belt use in the rear seat is lower compared to the front seat, especially when the driver is young. The SBR has been shown to be effective in the front seat, and should therefore have the same specifications in the rear seat. BACKGROUND It is well known that seat belt usage is one of the most effective ways to protect occupants in car crashes. A modern seat belt reduces the risk of death of approximately 50% [1]. Combined with airbag the protective effect is approximately 65% [2]. In 2018, average seat belt use in Europe was 83% for drivers and 81% for front seat passengers [1]. Unfortunately, seat belt use in the rear seat is still much lower, where the average usage rate is 60%. It is a global pattern that the seat belt usage rate in the rear seat is lower than in the front seat.

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.

Objective: Whiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically <25km/h) in impacts from all directions. Rear impacts, however, are the most common in the injury statistics. Females have a 1.5-3times higher risk of whiplash injury than males.Improved seat design is the prevailing means of increasing the protection of whiplash injury for occupants in rear impacts. Since 1997, more advanced whiplash protection systems have been introduced on the market, the Saab Active Head Restraint (SAHR) being one of the most prominent. The SAHRwhich is height adjustableis mounted to a pressure plate in the seatback by means of a spring-resisted link mechanism.Nevertheless, studies have shown that seats equipped with reactive head restraints (such as the SAHR) have a very high injury-reducing effect for males (approximate to 60-70%) but very low or no reduction effect for females. One influencing factor could be the position of the head restraint relative to the head, because a number of studies have reported that adjustable head restraints often are incorrectly positioned by drivers.The aim was to investigate how female and male Saab drivers adjust the seat in the car they drive the most.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 -26mm (head below the head restraint) for small females to an average of 82mm (head above the head restraint) for large males. On average, the offset was 23mm for females, which is within a satisfactory range and in accordance with recommendations; the corresponding value for males was 72mm.The backset tended to be shorter among female volunteers (on average 27mm) compared to the male volunteers (on average 44mm). 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.

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.

Whiplash injuries account for the vast majority of casualties in road traffic crashes, leading to long-term consequences. The majority occur in rear-ends crashes. Consumer crash tests play an important role in promoting effective concepts to reduce the problem. The current Euro New Car Assessment Program (NCAP) whiplash test protocol includes three sled tests at varying impact speeds and pulse shapes using a BioRID test dummy and 8 measures to assess whiplash potential based on previous best practice. Given the complexity of the test and with more experience, a real-world evaluation of the current protocol was undertaken. Three analyses were undertaken comprising an analysis of test outcome data, a logistic regression analysis, a receiver operating characteristic (ROC) analysis, and a correlation analysis comparing crash and injury outcome. 13,389 drivers reporting whiplash injury symptoms to Folksam Insurance in Sweden were studied, of which 1,266 occurred in cars tested by Euro NCAP. For all occupants reporting initial symptoms, the risk of permanent medical impairment was followed up according to the procedure used by Swedish insurance companies. Test scores according to Euro NCAP, JNCAP and IIWPG protocols were calculated, as well as combinations of the three Euro NCAP pulses. For each combination or protocol, the test score was compared with the real-world outcome. A correlation analysis of the included injury criteria was also performed for the three crash pulses included. The results showed that overall Euro NCAP, Japan New Car Assessment Program (JNCAP) and International Insurance Whiplash Prevention Group (IIWPG) all predict real-world whiplash injury outcome in terms of Permanent Medical Impairment (PMI). Based on limited data available, there was no statistical evidence using logistic regression and ROC analyses that any of the three tests performed better than any other. Correlations between the test scenarios of each of the three protocols, as well as the outcome associations with crash outcomes, suggested consistent improvements in the risk of permanent medical impairment. The main strength of the analyses conducted here was to show the validity of Euro NCAP, JNCAP and IIWPG whiplash test protocols when measured against real-world crash outcomes, which are the most important criteria showing that the tests are appropriately designed to help prevent injuries among the community. Some caution needs to be taken with these findings as many were not statistically significant because of the limited number of cases available. Further evaluation when additional data are available is warranted.

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 3years 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.