Bicycle accidents - do we only see the tip of the iceberg? A prospective multi-centre study in a large German city combining medical and police data

Mobility Infrastructures and Health: Scoping Review of studies in Europe

Objectives

Movement-friendly environments with infrastructure favouring active mobility are important for promoting physical activity. This scoping literature review aims at identifying the current evidence for links between mobility infrastructures and (a) behaviour regarding active mobility, (b) health outcomes and (c) co-benefits.

Method

This review was conducted in accordance with the PRISMA scoping review guidelines using PubMed and EMBASE databases. Studies included in this review were conducted in Europe, and published between 2000 and March 2023.

Results

146 scientific articles and grey literature reports were identified. Connectivity of sidewalks, walkability, and accessibility of shops, services and work are associated with walking. Cycling is positively associated with cycle-paths, separation of cycling from traffic and proximity to greenspaces, and negatively associated with traffic danger. Increased active transportation has a protective effect on cardiovascular and respiratory health, obesity, fitness, and quality of life. Co-benefits result from the reduction of individual motorized transportation including reduced environmental pollution and projected healthcare expenditure.

Conclusion

Mobility infrastructure combined with social and educational incentives are effective in promoting active travel and reducing future healthcare expenses. A shift to active transportation would increase both individual and community health and decrease greenhouse gas emissions.

Comparison of single bicycle crashes and collisions among severely injured cyclists-A 16-year analysis based on the Helsinki Trauma Registry (HTR)

OBJECTIVE

The Finnish national Traffic Safety Strategy 2022-2026 seeks to halve the number of road fatalities and serious injuries from 2020 to 2030. The strategy states that better information on bicycle crashes is needed for safety promotion. The aim of this study was to describe the demographics, injury characteristics, alcohol involvement, and helmet use of severely injured cyclists and to compare single bicycle crashes (falling alone or hitting a fixed object) to collisions.

MATERIAL AND METHODS

We identified all bicycle crashes between 2006 and 2021 from the Helsinki Trauma Registry (HTR). Variables analysed were basic patient demographics, Abbreviated Injury Scale (AIS) codes, AIS 3+ injuries, injured body regions, patient Injury Severity Score (ISS) and New Injury Severity Score (NISS), 30-day in-hospital mortality, ICU length of stay, injury mechanism, alcohol use by the injured cyclists, and helmet use.

RESULTS

Of the 325 severe (NISS >15) cycling injury patients in the HTR, 53.5 % were injured in single crashes and 46.5 % in collisions with a moving object. Most (71.4 %) patients were men and mean age of all patients was 54.1 years (SD 16.7). Alcohol was detected in 23.1 % of cases and more often in single crashes (32.8 %) than in collisions (11.9 %). Less than a third (29.2 %) of all cyclists wore a helmet; those who wore a helmet had fewer serious (AIS 3+) head injuries than those who did not. Cyclists injured in collisions had higher ISS and NISS scores than those injured in single crashes. Serious (AIS 3+) injuries in extremities or in pelvic girdle were more common in collisions than in single crashes.

CONCLUSIONS

Among severely injured cyclists, single bicycle crashes were more common; alcohol was more often detected in single bicycle crashes than in collisions. Overall injury severity was higher in collisions than in single crashes. Helmet users had less AIS 3+ head injuries than non-users. Attention should be focused on preventing alcohol-related cycling injuries, promoting use of bicycle helmets, and more precise and comprehensive documentation of bicycle crashes in health care units.

Comparison of the number of pedestrian and cyclist injuries captured in police data compared with health service utilisation data in Toronto, Canada 2016-2021

INTRODUCTION

Pedestrian and cyclist injuries represent a preventable burden to Canadians. Police-reported collision data include information on where such collisions occur but under-report the number of collisions. The primary objective of this study was to compare the number of police-reported collisions with emergency department (ED) visits and hospitalisations in Toronto, Canada.

METHODS

Police-reported collisions were provided by Toronto Police Services (TPS). Data included the location of the collision, approximate victim age and whether the pedestrian or cyclist was killed or seriously injured. Health services data included ED visits in the National Ambulatory Care Reporting System and hospitalisations from the Discharge Abstract Database using ICD-10 codes for pedestrian and cycling injuries. Data were compared from 2016 to 2021.

RESULTS

Injuries reported in the health service data were higher than those reported in the TPS for cyclists and pedestrians. The discrepancy was the largest for cyclists treated in the ED, with TPS capturing 7.9% of all cycling injuries. Cyclist injuries not involving a motor vehicle have increased since the start of the pandemic (from 3629 in 2019 to 5459 in 2020 for ED visits and from 251 in 2019 to 430 for hospital admissions).

IMPLICATIONS

While police-reported data are important, it under-reports the burden. There have been increases in cyclist collisions not involving motor vehicles and decreases in pedestrian injuries since the start of the pandemic. The results suggest that using police data alone when planning for road safety is inadequate, and that linkage with other health service data is essential.

[Bicycle accidents in the course of time in Münster, Germany : Analysis of changes in bicycle accidents over the past 10 years]

BACKGROUND

Bicycles have been a popular means of transport for many years. Especially in times of increased climate discussion, the bicycle has moved further into focus as an environmentally friendly and cost-effective means of transport. Bike lanes and roads are becoming more crowded and new means of transport such as pedelecs or e‑scooters are emerging.

METHODS

A total of four studies by Münster University Hospital on bicycle accidents and the official accident statistics of the Münster police were compared. In the period from 2009 to 2019, three studies were conducted that considered all bicycle accidents and one study that only considered pedelec riders separately.

RESULTS

The age distribution as well as main causes of accidents remained almost the same over the years. The number of pedelec accidents has increased. Pedelec riders have a higher average age and a higher proportion of intensive care stays; however, this cohort also has a high rate of helmet wearers. Overall, the willingness to wear a helmet seems to have increased.

CONCLUSION

It should be considered that with increasing bicycle traffic, safety measures must be increased accordingly. In this respect, accident prevention should focus on three major areas, engineering, education and enforcement.

[The severely injured older cyclist-Evaluation of the TraumaRegister DGU® : Retrospective, multicenter cross-sectional study based on the TraumaRegister DGU®]

BACKGROUND

Contrary to the trend of decreasing traffic fatalities, the number of cyclists killed in Germany has been steadily increasing in recent years. With the increasing popularity of cycling in all age groups, the number of accidents with sometimes serious injuries is rising. In the course of this, the question arises what influence age has on the type and severity of injuries, the probability of survival and the length of hospital stay in seriously injured cyclists.

METHODS

A retrospective analysis of data from the TraumaRegister DGU® (TR-DGU) from 2010 to 2019 was performed. All severely injured cyclists with a maximum abbreviated injury scale (MAIS) of 3+ (n = 14,651) in the TR-DGU were included in this study and the available parameters were evaluated. A subdivision into three age groups (60-69, 70-79, and ≥ 80 years) and a control group (20-59 years) was carried out.

RESULTS

Injuries to the head were by far the most common, accounting for 64.2%. There was a marked increase in severe head injuries in the 60-plus years age group. Furthermore, with increasing age, the probability of prehospital intubation, catecholamine requirement, intensive care and hospital length of stay, and mortality increased.

CONCLUSION

Head injuries represent the most common serious injury, especially among older cyclists. As helmet wearing was not recorded in the TraumaRegister DGU® during the evaluation period, no conclusion can be drawn about its effect. Furthermore, a higher age correlates with a longer hospital stay and a higher mortality, but does not represent an independent risk factor for death in severely injured patients.

Development of German pedelec (and bicycle) crashes between 2013 and 2021

INTRODUCTION

The continuous growth in the use of e-bikes (in Germany mostly pedelecs that support pedaling up to 25 km/h) raises questions about the use of historic crash data for the development of road safety measures. The aim of this study was to address this issue, by conducting a longitudinal analysis of pedelec and bicycle crash data over a period of nine years to identify trends and to clarify whether such trends are specific to pedelecs.

METHOD

We analyzed 95,338 police reported pedelec and bicycle injury crashes from 2013 through 2021. The dataset consisted of crashes from three federal states of Germany: Brandenburg, Hesse and Saxony. Data were analyzed with respect to sex and age distribution, time, location and type of accident, conflict partner, cause of crash and injury severity.

RESULTS

Many of the analyzed variables showed a considerable degree of temporal stability, with differences as well as similarities between the two bicycle types staying quite consistent over the years. One notable difference was the mean age of the involved riders, with crashed pedelec riders being significantly older than conventional cyclists. At the same time, however, the mean age of these pedelec riders has decreased by eight years over time. Single vehicle crashes were consistently more common for pedelec riders than for cyclists. Similarly, pedelec rider crashes went with a higher injury severity over all the years.

CONCLUSIONS AND PRACTICAL APPLICATIONS

While, on a more detailed level, we found differences between the two bicycle types, overall crash characteristics were remarkably similar and consistent over time. Our findings provide no clear argument for road safety measures that are specifically designed to target pedelecs. Instead, the stable crash total, and the increases in ridership of both bicycles and pedelecs, highlight the demand for new, innovative solutions to improve cycling safety in general.

Wider view over bicycle crashes: Complementing and extending bicycle crash statistics in urban areas using surveys

INTRODUCTION

In pursuit of sustainability goals, many cities are introducing measures to increase the usage of bicycles as a means of transportation. City planners aim to ensure that this increase does not lead to an increase in crashes, but must make corresponding infrastructure decisions with limited information. Sufficient data to perform a statistical analysis of location-specific crash frequencies is rarely available. For example, only approximately 10% of all bicycle crashes are reported to the police (Shinar et al., 2018). Therefore, urban planners often rely on expert opinion, which may lead to suboptimal prioritization and realization of infrastructure improvements.

METHOD

This paper demonstrates how surveys on bicycle crashes can be used to aid urban planners in making infrastructure decisions. In addition to confirming the location and characteristics of reported crashes, surveys can uncover characteristics of crashes that are not reported to the police, situations in which a crash almost occurred, and locations perceived by cyclists to be dangerous. Surveys also allow urban planners to investigate non-infrastructure related causes of crashes, such as the frequency with which individual cyclists use other modes of transportation.

PRACTICAL APPLICATIONS

The usefulness of surveys in the determination of urban cycling safety is demonstrated in this paper through analysis of survey results from the city of Zurich in 2018.

Epidemiology of Paediatric Trauma During National Lockdown: A Retrospective Study With 12 Months of Follow-Up

Introduction The COVID-19 pandemic and its associated preventative measures such as national lockdown dramatically changed the daily activities of children. This paper aims to compare the epidemiology of paediatric orthopaedic trauma presentation, management and outcomes during the school closure period with the matched pre-pandemic period in 2019. Methods This was a retrospective cohort study of data collected from the West Yorkshire Trauma Network, comprising a major trauma centre, Leeds General Infirmary, and five peripheral trauma units. All patients aged 0-18 years who required trauma unit management during the school closure period (18 March 2020-25 May 2020) were included. Cases for the matched period in 2019 were analysed for baseline comparison. Patient demographics, mechanism and anatomical location of injury, management and follow-up were assessed. Results In the 2020 and 2019 cohorts, 286 and 575 injuries were observed, respectively. In the 2020 cohort, we observed a 50.3% (n=289) fall in paediatric trauma presentation and a significant proportional reduction in referrals from the emergency department (22% (n=63) versus 53% (n=305); p<0.001). There was also a significant reduction in the average age at presentation by more than one year (p<0.001). Sports-related injuries decreased significantly (n=16 (5.6%) versus n=127 (22.1%); p<0.001). While the proportion of ride-on injuries increased significantly, overall numbers remained similar (n=63 (22%) versus n=61 (10.6%); p<0.0001). Non-accidental injury (NAI) concerns rose significantly (n=9 (3.1%) versus n=4 (0.7%); p=0.01), but the absolute number of confirmed NAI cases stayed the same (n=2). There was a proportional increase in upper limb injuries (64.3% (n=184) versus 58.4% (n=336); p>0.05) and a proportional reduction in lower limb injuries (32.1% (n=92) versus 35.5% (n=204); p>0.05). However, the rate of tibial shaft injuries rose significantly (10.1% (n=29) versus 5.2% (n=30); p=0.02). The use of conservative management increased with a significant delay in average time to surgery from the date of injury (8.5 days versus 3.1 days; p=0.01). Patients who were only followed up with a telephone consultation rose significantly (23% (n= 66) versus 6% (n=35); p<0.001). Re-presentation rate increased significantly (1.4% (n=4) versus 0.2% (n=12); p=0.04). Conclusion Our study showed a reduction in paediatric trauma presentations during the pandemic and a significant reduction in the average age at presentation. This change has been accompanied by a shift in the mechanism and anatomical location of injury, management and subsequent follow-up.

Bicycle infrastructure and the incidence rate of crashes with cars: A case-control study with Strava data in Atlanta

Introduction

Bicycling has individual and collective health benefits. Safety concerns are a deterrent to bicycling. Incomplete data on bicycling volumes has limited epidemiologic research investigating safety impacts of bicycle infrastructure, such as protected bike lanes.

Methods

In this case-control study, set in Atlanta, Georgia, USA between 2016-10-01 and 2018-08-31, we estimated the incidence rate of police-reported crashes between bicyclists and motor vehicles (n = 124) on several types of infrastructure (off-street paved trails, protected bike lanes, buffered bike lanes, conventional bike lanes, and sharrows) per distance ridden and per intersection entered. To estimate underlying bicycling (the control series), we used a sample of high-resolution bicycling data from Strava, an app, combined with data from 15 on-the-ground bicycle counters to adjust for possible selection bias in the Strava data. We used model-based standardization to estimate effects of treatment on the treated.

Results

After adjustment for selection bias and confounding, estimated ratio effects on segments (excluding intersections) with protected bike lanes (incidence rate ratio [IRR] = 0.5 [95% confidence interval: 0.0, 2.5]) and buffered bike lanes (IRR = 0 [0,0]) were below 1, but were above 1 on conventional bike lanes (IRR = 2.8 [1.2, 6.0]) and near null on sharrows (IRR = 1.1 [0.2, 2.9]). Per intersection entry, estimated ratio effects were above 1 for entries originating from protected bike lanes (incidence proportion ratio [IPR] = 3.0 [0.0, 10.8]), buffered bike lanes (IPR = 16.2 [0.0, 53.1]), and conventional bike lanes (IPR = 3.2 [1.8, 6.0]), and were near 1 and below 1, respectively, for those originating from sharrows (IPR = 0.9 [0.2, 2.1]) and off-street paved trails (IPR = 0.7 [0.0, 2.9]).

Conclusions

Protected bike lanes and buffered bike lanes had estimated protective effects on segments between intersections but estimated harmful effects at intersections. Conventional bike lanes had estimated harmful effects along segments and at intersections.

An Air-Filled Bicycle Helmet for Mitigating Traumatic Brain Injury

We created a novel air-filled bicycle helmet. The aims of this study were (i) to assess the head injury mitigation performance of the proposed helmet and (ii) to compare those performance results against the performance results of an expanded polystyrene (EPS) traditional bicycle helmet. Two bicycle helmet types were subjected to impacts in guided vertical drop tests onto a flat anvil: EPS helmets and air-filled helmets (Bumpair). The maximum acceleration value recorded during the test on the Bumpair helmet was 86.76 ± 3.06 g, while the acceleration during the first shock on the traditional helmets reached 207.85 ± 5.55 g (p < 0.001). For the traditional helmets, the acceleration increased steadily over the number of shocks. There was a strong correlation between the number of impacts and the response of the traditional helmet (cor = 0.94; p < 0.001), while the Bumpair helmets showed a less significant dependence over time (cor = 0.36; p = 0.048), meaning previous impacts had a lower consequence. The air-filled helmet significantly reduced the maximal linear acceleration when compared to an EPS traditional helmet, showing improvements in impact energy mitigation, as well as in resistance to repeated impacts. This novel helmet concept could improve head injury mitigation in cyclists.

[E-scooter, e-bike and bicycle injuries in the same period-A prospective analysis of a level 1 trauma center]

BACKGROUND

The actual number of accidents in e‑scooter drivers in Germany seems to be significantly higher than the current figures from the Statistisches Bundesamt suggest. This epidemiological study examines e‑scooter injuries and compares them with e‑bike and bicycle injuries.

OBJECTIVE

In order to create a comparable database on the dangers of e‑scooters, e‑bikes and bicycles, the typical injury patterns were analyzed and prevention options derived from them.

MATERIAL AND METHODS

All accidents involving e‑scooters, e‑bikes and bicycles that were presented via the university emergency room of a level 1 trauma center between 15 June 2019 and 31 October 2020 were prospectively investigated.

RESULTS

In our study, 68 accidents in e‑scooter drivers were included, of which only 11.8% (n = 8) were recorded by the police. Significantly more of them were male than female (p = 0.032) with a mean age of 31.1 (±13) years. At the same time, we registered 34 accidents in e‑bike riders and 356 in cyclists. In all three groups, most injuries occurred to the head, followed by injuries to the upper extremities. Significantly more e‑scooter drivers had an ISS ≥ 16 than in the group of injured cyclists (p = 0.016). E‑scooter riders who had an accident had a significantly longer length of stay in hospital, than e‑bike riders (p = 0.003) and cyclists (p = 0.001), 52.9% (n = 18) of e‑bike riders and 53.3% (n = 113) cyclists wore a helmet, compared to only 1.5% (n = 1) of e‑scooter riders. The most common cause of accidents among e‑bike riders (17.7%; n = 6) and cyclists (10.4%; n = 37) was slipping away on tram rails, while for e‑scooter riders it was colliding with a curb (7.4%; n = 5).

CONCLUSION

The three patient collectives examined showed different causes and profiles of injuries. The reasons for an increased proportion of seriously injured people compared to cyclists are electromobility, driving under the influence of alcohol and inadequate wearing of a helmet on e‑scooters when head injuries dominate. 73.5% (n = 50) of the e‑scooter accidents recorded by us were not registered by the police and therefore do not appear in the current statistics of the statistisches Bundesamt. As a result, a much higher number of e‑scooter accidents can be assumed. Preventive measures could include the introduction of compulsory helmets, a higher number of traffic controls and the expansion of bike tracks.

Evaluating the effect of drunk driving on fatal injuries among vulnerable road users in Taiwan: a population-based study

Background

Most studies have focused on injuries sustained by intoxicated drivers themselves, but few have examined the effect of drunk driving on injury outcomes among VRUs (vulnerable road users) in developing countries. This study aims to evaluate the effect of drunk driving on fatal injuries among VRUs (pedestrians, cyclists, or motorcyclists).

Methods

The data were extracted from the National Taiwan Traffic Crash Dataset from January 1, 2011, to December 31, 2019. Crashes involving one motorized vehicle and one VRU were considered. This study examines the effect of drunk driving by estimating multivariate logistic regression models of fatal injuries among VRUs after controlling for other variables.

Results

Among 1,416,168 casualties, the fatality rate of VRUs involved in drunk driving was higher than that of general road users (2.1% vs. 0.6%). Drunk driving was a significant risk factor for fatal injuries among VRUs. Other risk factors for fatal injuries among VRUs included VRU age ≥ 65 years (adjusted odds ratio [AOR]: 5.24, 95% confidence interval [CI]: 5.53–6.07), a nighttime accident (AOR: 4.52, 95% CI: 4.22–4.84), and being hit by a heavy-duty vehicle (AOR: 2.83, 95% CI: 2.26–3.55). Subgroup analyses revealed a linear relationship between driver blood alcohol concentration (BAC) and the risk of fatal injury among motorcyclists. Motorcyclists exhibited the highest fatality rate when they had a BAC ≤ 0.03% (AOR: 3.54, 95% CI: 3.08–4.08).

Conclusion

Drunk driving was associated with a higher risk of fatality for all VRUs. The risk of fatal injury among motorcyclists was linearly related to the BAC of the drunk drivers. Injuries were more severe for intoxicated motorcyclists, even those with BAC ≤ 0.03%, which is within the legal limit.

Road Users’ Reports on Danger Spots: The Crowd as an Underestimated Expert?

As part of the project EDDA+ (Early Detection of Dangerous Areas in road traffic using smart data), a web-based crowdsourcing platform has been launched on which road users can report danger spots they face in everyday traffic. Whereas official police collision data can only be used reactively, these user reports are intended to warn other road users and provide road safety stakeholders with detailed information for proactive measures. Since this approach is relatively novel, the present pilot study aimed to evaluate the validity of these subjective road user reports. A quasi-randomized sample of N = 77 danger spots distributed over four major German cities was audited using a 70-item objective road safety deficit inventory to identify infrastructural deficits. Based on these items, an overall rating of objective hazardousness for each danger spot was derived. In more than half of the audited danger spots, infrastructural deficits were identified in the audit (=confirmed hazard). In another quarter of audited dangers spots, the reported hazard could not be identified without any doubt due to a lack of infrastructural deficit or detailed information about the nature of the hazard (=uncertain, no certain match between audit and report). Our analysis further revealed that an increased number of road user interactions for the respective danger spot yielded a higher likelihood of confirmation of a danger spot’s hazardousness. Descriptively, pedestrians and bicyclists were most often mentioned as exposed to danger, with the most prevalent nature of danger being areas with poor visibility and misconduct by drivers. The results were blended with police collision data in the next step. We did not find a significant relationship between our danger spots’ rating and the number of collisions at the respective spot. Our results indicate that reports of danger spots and the increased user related activity can serve as an indicator for the early detection of road traffic hazards.

Crash risk and subjective risk perception during urban cycling: Accounting for cycling volume

Most research concerned with cyclists' safety has been focused on the crash risk (i.e. their objective safety). However, there has been a growing interest in the perceived level of this risk (i.e. the subjective safety of cyclists). Crash risk and subjective risk perception in urban cycling appear to be mostly well aligned. For example, reduced speed limits have been found to reduce both objective and subjective risks (although there is also evidence for some incongruences). This absolute number of incidents could be misleading, as it does not account for potential differences in cycling volume (i.e. cyclists are likely to prefer streets with reduced speed limits). Thus, it may be important to adjust the absolute number of incidents relative number to the local cycling volume. In this research, we investigate the relation of cycling crashes and subjective risk perception (operationalized through reports from a crowd-sourcing project) for different types of cycling infrastructure and different speed limits, while accounting for the local cycling volume. We find that the absolute number of VGI reports and crashes can be misleading: whereas the absolute incident numbers, for example, suggest few benefits of cycling lanes and tracks, adjusting for the cycling volume reveals an increase of both objective and subjective safety as compared to streets without cycling infrastructure. We also identify situations where cyclists apparently underestimate the crash risk (i.e. on cycleways opposing the cars' traveling direction, and at streets with a speed limit of 30 km/h intersecting streets with higher speed limits). Additional research is required to understand the sources of these discrepancies, and how to make cyclists aware of them.

Patterns and clinical outcomes of injuries related to two-wheeled vehicles (bicycle and motorcycle) in the geriatric population: a nationwide analysis in South Korea (2016-2018)

Background

South Korea has a rapidly ageing population. This study aimed to provide epidemiologic data and to identify the characteristics of the patterns and clinical outcomes of two-wheeled vehicle-related injuries (bicycle and motorcycle) in elderly riders.

Methods

This study retrospectively analyzed data from the National Emergency Department Information System from 2016 to 2018. Adult patients (≥ 20 years old) who were injured while using two-wheeled vehicles were included. Elderly patients were defined as being 65 years and older. The analysis was performed for 65,648 bicycle-related injuries (15,272 elderly patients) and 87,855 motorcycles-related injuries (17,292 elderly patients).

Results

In emergency departments (EDs), the average injury severity score (ISS) for motorcycle-related accidents was 9.8 ± 11.2 in the younger group and 14.1 ± 14.7 in the elderly group (p = 0.001). In addition, the average ISS of bicycle-related accidents was 7.1 ± 8.9 in the younger group and 10.5 ± 12.3 in the elderly group (p = 0.001). Two-wheeled vehicle accident mortality rates of elderly riders (0.9% for bicycle and 1.8% for motorcycle in the ED; 4.1% for bicycle and 3.8% for motorcycle in the hospital) were more than twice those of younger riders.

The elderly stayed in the hospital longer than younger patients (485.2 ± 543.0 h vs 336.8 ± 385.5 h, p = 0.001) for bicycle-related injuries. They also stayed longer for motorcycle-related injuries (529 ± 598.6 h vs 452.0 ± 543.55 h, p = 0.001).

The logistic regression analysis showed that age ≥ 65 years was an independent factor associated with severe trauma (ISS ≥ 16) for both bicycle-related injuries (adjusted odds ratio [OR] 2.185 [95% Confidence Interval (CI) 2.072–2.303]) and motorcycle-related injuries (adjusted OR 1.220 [95% CI 1.137–1.287]).

Conclusion

Two-wheeled vehicle-related injuries in the elderly were associated with higher ISS, length of hospital stay, and mortality than in younger riders. Analysing the characteristics of two-wheeled vehicle-related injuries in the elderly can be the basis for planning to reduce and prevent injuries in elderly riders.

A probabilistic approach to online classification of bicycle crashes

When a bicycle crash takes place, it is paramount for an emergency center to recognize the physical state of the cyclist as early as possible. However, an injured bicyclist may be incapable of making a phone call to the emergency center. In this study, we propose an online approach to classify bicycle crashes based on signals from an onboard inertial measurement unit (IMU), which can be used as a trigger function for an automatic emergency system. For this purpose, we define several bicycle crash features according to the kinematic properties of bicycle accidents. The input signals (variables) influencing the individual crash features are determined by the ANOVA method (analysis of variance). With the determined input signals, probabilistic models for each crash feature are trained on the base of logit models and 20,000 km naturalistic driving data including 20 real crashes. In addition, further crash and corner case data has been collected for the model training. A decision tree describing all probabilistic crash features is used to classify different kinematic events and crash scenarios. A series of driving tests with a crash-dummy and a crash-car are performed to verify the proposed crash classification approach, showing a sensitivity of 96.8%, a specificity of 99.6% and an accuracy of 99.5% of the trained model.

Cycling injuries requiring orthopaedic intervention during the first COVID-19 lockdown period: A multi-centre SCottish Orthopaedic Research collaborativE (SCORE) study

Introduction

The COVID-19 lockdown resulted in decreased vehicle use and an increased uptake in cycling. This study investigated the trends in cycling-related injuries requiring orthopaedic intervention during the COVID-19 lockdown period compared with similar time periods in 2018 and 2019.

Methods

Data were collected prospectively for patients in 2020 and collected retrospectively for 2019 and 2018, from hospitals within four NHS Scotland Health Boards encompassing three major trauma centres. All patients who sustained an injury as a result of cycling requiring orthopaedic intervention were included. Patient age, sex, mechanism of injury, diagnosis and treatment outcome from electronic patient records.

Results

Number of injuries requiring surgery 2020: 77 (mean age/years – 42.7); 2019: 47 (mean age/years - 42.7); 2018: 32 (mean age/years – 31.3). Overall incidence of cycling injuries 2020: 6.7%; 2019: 3.0%; 2018: 2.1%. Commonest mechanism of injury: fall from bike 2020 n = 54 (70.1%); 2019 n = 41 (65.1%); 2018 n = 25 (67.6%). Commonest injury type: fracture 2020 n = 68 (79.1%); 2019 n = 33 (70.2%); 2018 n = 20 (62.5%). Commonest areas affected: Upper extremity: 2020 n = 45 (58.5%); 2019 n = 25 (53.2%); 2018 n = 25 (78.1%). Lower extremity: 2020 n = 23 (29.9%); 2019 n = 14 (29.7%); 2018 n = 7 (21.8%).

Conclusion

A significant increase in the number of cycling related injuries requiring orthopaedic intervention, a greater proportion of female cyclists and an older mean age of patients affected was observed during the COVID-19 lockdown period compared with previous years. The most common types of injury were fractures followed by lacerations and fracture-dislocations. The upper extremity was the commonest area affected.

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

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

E-scooter incidents in Berlin: an evaluation of risk factors and injury patterns

BACKGROUND

E-scooters have emerged as a frequently used vehicle in German cities due to their high availability and easy access. However, investigations about the causes and mechanisms of E-scooter incidents and their trauma-specific consequences are rare.

METHODS

We analysed all patients involved in E-scooter incidents from June to December 2019 who presented to four inner-city EDs in Berlin. The prospective data included patient-related and incident-related data, information on injury patterns and therapy, responses in a voluntary questionnaire concerning E-scooter use and general traffic experience.

RESULTS

248 patients (129 males; median age 29 years (5-81)) were included: 41% were tourists and 4% were children. Most incidents (71%) occurred between July and September 2019, the majority occurring at weekends (58%). The injury pattern was mostly multifocal, affecting the lower (42%) and upper limbs (37%) and the head (40%). Traumatic brain injury was associated with alcohol consumption. Inpatient admission was recorded in 25%, surgery in 23%.

CONCLUSION

This study has defined the incidence of injury related to E-scooter use in a major European city. Stricter laws governing the use of E-scooters, the wearing of helmets and technical modifications to the E-scooter platforms might decrease E-scooter-associated incidents and resulting injuries in the future.

TRIAL REGISTRATION NUMBER

German Clinical Trials Registry (DRKS00018061).

An in-depth analysis of self-reported cycling injuries in single and multiparty bicycle crashes in Denmark

INTRODUCTION

Cycling is one of the main forms of transportation in Denmark. However, while the number of traffic crash fatalities in the country has decreased over the past decade, the frequency of cyclists killed or seriously injured has increased. The high rate of serious injuries and fatalities associated with cycling emphasizes the increasing need for mitigating the severity of such crashes.

METHOD

This study conducted an in-depth analysis of cyclist injury severity resulting from single and multiparty bicycle-involved crashes. Detailed information was collected using self-reporting data undertaken in Denmark for a 12-month period between 1 November 2012 and 31 October 2013. Separate multilevel logistic (MLL) regression models were applied to estimate cyclist injury severity for single and multiparty crashes. The goodness-of-fit measures favored the MLL models over the standard logistic models, capturing the intercorrelation among bicycle crashes that occurred in the same geographical area.

RESULTS

The results also showed that single bicycle-involved crashes resulted in more serious outcomes when compared to multiparty crashes. For both single and multiparty bicycle crash categories, non-urban areas were associated with more serious injury outcomes. For the single crashes, wet surface condition, autumn and summer seasons, evening and night periods, non-adverse weather conditions, cyclists aged between 45 and 64 years, male sex, riding for the purpose of work or educational activities, and bicycles with light turned-off were associated with severe injuries. For the multiparty crashes, intersections, bicycle paths, non-winter season, not being employed or retired, lower personal car ownership, and race bicycles were directly related to severe injury consequences. Practical Applications: The findings of this study demonstrated that the best way to promote cycling safety is the combination of improving the design and maintenance of cycling facilities, encouraging safe cycling behavior, and intensifying enforcement efforts.

Improving knowledge of cyclist crashes based on hospital data including crash descriptions from open text fields

INTRODUCTION

In this study we explore the added value of bicycle crash descriptions from open text fields in hospital records from the Aarhus municipality in Denmark. We also explore how bicycle crash data from the hospital complements crash data registered by the police in the same area and time period.

METHOD

The study includes 5,313 Danish bicycle crashes, of which 4,205 were registered at the hospital and 1,078 by the police. All crashes occurred from 2010 to 2015. We performed an in-depth analysis of the open text fields on hospital records to identify factors associated with each crash using four categories: bicyclist, road, bicycle, and the other party. We employed the chi-squared test to compare the distribution of variables between crashes registered at the hospital and by the police. A binary logit model was used to estimate the probability that a crash factor is identified, and that each crash factor is associated with a single-bicycle crash.

RESULTS

The open-ended text fields in hospital records provide detailed information about crash factors not available in police records, including riding speed, inattention, clothing, specific road conditions, and bicycle defects. The factors alcohol and curb had the highest odds of being identified in relation to a single-bicycle crash. Crash data registered at the hospital included a larger number of bicycle crashes, particularly single-bicycle crashes and crashes with slight injuries only.

CONCLUSION

Crash information registered at the hospital in Aarhus Municipality contributes to a better understanding of bicycle crashes due to detailed information about crash-associated factors as well as information about a larger number of bicycle crashes, particularly single-bicycle crashes. Practical implication: Efforts to improve access to detailed information about bicycle crashes are needed to provide a better basis for bicycle crash prevention.

Severe traffic injuries in the Helsinki Trauma Registry between 2009-2018

OBJECTIVE

The European Union (EU) has adopted the Vision Zero and Safe System approach to eliminate deaths and serious traffic injuries on European roads by 2050. Detailed information on serious injuries, injury mechanisms and consequences are needed. The aim of this study was to describe and compare by injury mechanism the demographics, injuries, injury severity, and treatment of seriously injured road traffic trauma patients.

MATERIAL AND METHODS

We analysed data on severe traffic injury trauma patients aged ≥16 years of the Helsinki Trauma Registry (HTR) covering the years 2009-2018. The variables analysed were basic patient demographics, injury mechanism, Abbreviated Injury Scale (AIS) codes, injured body regions, patient Injury Severity Score (ISS) and New Injury Severity Score (NISS) values, NISS groups (NISS 16-24 and NISS ≥25), AIS 3+ injuries, trauma bay and 30-day mortality, length of stay (LOS) at ICU and in hospital, surgeries performed, pre-injury classification, and intention of injury.

RESULTS

A total of 1 063 traffic injury patients were analysed; 38.6% were motor vehicle occupants, 28.5% motorcyclists or moped drivers, 17.2% bicyclists, and 15.7% pedestrians. The mean age of patients was 44.3 years (SD 20.2). Median ISS score was 22 and median NISS score was 27. Both scores were highest in pedestrians. Among all patients, total hospital LOS was 12 517 days (median 9) and total ICU LOS was 6 311 days (median 5). The most common AIS 3+ injuries according to ISS body regions were chest injuries (60%) and head or neck injuries (43.7%). Chest injuries occurred more frequently in motorcyclists and motor vehicle occupants, whereas head or neck injuries were most common among bicyclists and pedestrians.

CONCLUSIONS

Severely injured pedestrians and bicyclists were older and they had higher mortality than motorcyclists and motor vehicle occupants. According to NISS, the overall severity was highest among pedestrians followed by bicyclists. However, the both median ICU LOS and hospital LOS were highest for pedestrians but lowest for bicyclists. The most common AIS 3+ injuries were chest and head or neck injuries. To specify effective injury prevention measures, hospital data should be complemented with information on the circumstances of the accident.

Cyclist crash rates and risk factors in a prospective cohort in seven European cities

Increased cycling uptake can improve population health, but barriers include real and perceived risks. Crash risk factors are important to understand in order to improve safety and increase cycling uptake. Many studies of cycling crash risk are based on combining diverse sources of crash and exposure data, such as police databases (crashes) and travel surveys (exposure), based on shared geography and time. When conflating crash and exposure data from different sources, the risk factors that can be quantified are only those variables common to both datasets, which tend to be limited to geography (e.g. countries, provinces, municipalities) and a few general road user characteristics (e.g. gender and age strata). The Physical Activity through Sustainable Transport Approaches (PASTA) project was a prospective cohort study that collected both crash and exposure data from seven European cities (Antwerp, Barcelona, London, Örebro, Rome, Vienna and Zürich). The goal of this research was to use data from the PASTA project to quantify exposure-adjusted crash rates and model adjusted crash risk factors, including detailed sociodemographic characteristics, attitudes about transportation, neighbourhood built environment features and location by city. We used negative binomial regression to model the influence of risk factors independent of exposure. Of the 4,180 cyclists, 10.2 % reported 535 crashes. We found that overall crash rates were 6.7 times higher in London, the city with the highest crash rate, relative to Örebro, the city with the lowest rate. Differences in overall crash rates between cities are driven largely by crashes that did not require medical treatment and that involved motor-vehicles. In a parsimonious crash risk model, we found higher crash risks for less frequent cyclists, men, those who perceive cycling to not be well regarded in their neighbourhood, and those who live in areas of very high building density. Longitudinal collection of crash and exposure data can provide important insights into individual differences in crash risk. Substantial differences in crash risks between cities, neighbourhoods and population groups suggest there is great potential for improvement in cycling safety.

Cycling related major trauma in Ireland

INTRODUCTION

Cycling as a means of transport or recreational activity is increasing in popularity in Ireland. However, increasing numbers of cyclists may lead to an increased number of bicycle collisions and fatalities. The Road Safety Authority is the statutory body for road safety in Ireland but uses police data alone to collate cycling collision statistics. This may lead to an underestimation of cycling injuries in Ireland. Using hospital statistics may provide a greater understanding of cycling trauma in Ireland.

OBJECTIVE

The present study examines cycling related trauma in Ireland using the Major Trauma Audit (MTA) data collected via the Trauma and Research Network (TARN) from hospitals in Ireland for the period 2014 to 2016. The database was interrogated for demographics, mechanism of injury, injury characteristics and patient outcomes.

RESULTS

There were 410 cycling collisions recorded in the TARN database which represented 4.4% of trauma captured by TARN for the study period. Of this cohort 79% were male compared with 58% in the overall (TARN) trauma cohort (p < 0.001) and the median (IQR) age was 43.8 years (31.0, 55.7) which is younger than the median (IQR) of 58.9 (36.2, 76.0) years for the overall trauma cohort (p < 0.001). Cycling collisions had a median (IQR) injury severity score (ISS) of 10 (9, 20) which was higher than the overall trauma cohort ISS of 9 (9, 17). Of the mechanisms observed for cycling trauma, 31.7% (n = 130) had a collision with a motor vehicle. Of those who did not wear a helmet, 52.2% (n = 47) sustained a head injury compared with 27.5% (n = 44) in the group who were wearing a helmet (p < 0.001).

CONCLUSION

The TARN data presented in this paper builds a more complete overview of the burden of cycling collisions in Ireland. Particular points of focus are that serious cycling injuries occur in a predominantly male population, and that only around 30% of cases are recorded as involving a motor vehicle, with the majority having an unknown mechanism of injury. There was an association between helmets and head injuries in this study, but there are likely other contributing factors such as mechanism of injury, velocity or cycling infrastructure. Using hospital data such as the MTA provides valuable information on the injuries sustained by cyclists, but more prospective studies to capture injury mechanism and contributing factors are needed.

Mapping fractures from traffic accidents in Sweden: How do cyclists compare to other road users?

Introduction: Cyclists account for a large share of injured road users in traffic. The crash data analysis for cyclist safety and protection should be based on a representative dataset of real-world crashes. This manuscript aimed to explore the patterns of cyclists' fractures and factors associated with fractures of higher severity.Methods: This paper exemplifies a methodology that combines injuries from a crash database, including both hospital and police reports and fracture registry database from orthopedic centers nationally in Sweden.Results: Car occupants were most frequently involved in crashes resulting in fractures (37%), followed by motorcyclists (27.6%) and bicyclists (15.4%). Common fracture locations differed by the type of road user, where cyclists were more frequently fractured in the lower arm, compared to other road users, such as car drivers, motorcyclists and pedestrians who suffered mostly of fractures in the lower leg. Within cyclists, injuries also differed by gender, suggesting that combination of different countermeasures may be needed in order to provide sufficient protection for all cyclist. In the analyzed data, male cyclists with an average age of 49 were the most frequently fractured cyclists. Fractures of cyclists to the acetabulum (100%), pelvis (84.2%), vertebra (75%) and tibia (70.3%) were most frequently high energy fractures. Single bicycle incidents (OR = 0.165) and collisions with another bicycle (OR = 0.148) were significantly less likely to result in a high energy fracture than a collision with a car.Conclusions: The results of this study may guide the design of appropriate protective devices for the cyclists based on the different injury mechanisms and provide implications for prioritizing new countermeasures, campaigns, or regulations.

Characteristics of bicycle crashes among children and the effect of bicycle helmets

Objective: Focusing on children (0-17 years), this study aimed to investigate injury and accident characteristics for bicyclists and to evaluate the use and protective effect of bicycle helmets.Method: This nationwide Swedish study included children who had visited an emergency care center due to injuries from a bicycle crash. In order to investigate the causes of bicycle crashes, data from 2014 to 2016 were analyzed thoroughly (n = 7967). The causes of the crashes were analyzed and categorized, focusing on 3 subgroups: children 0-6, 7-12, and 13-17 years of age. To assess helmet effectiveness, the induced exposure approach was applied using data from 2006 to 2016 (n = 24,623). In order to control for crash severity, only bicyclists who had sustained at least one Abbreviated Injury Scale (AIS) 2+ injury (moderate injury or more severe) in body regions other than the head were included.Results: In 82% of the cases the children were injured in a single-bicycle crash, and the proportion decreased with age (0-6: 91%, 7-12: 84%, 13-17: 77%). Of AIS 2+ injuries, 8% were head injuries and 85% were injuries to the extremities (73% upper extremities and 13% lower extremities). Helmet use was relatively high up to the age of 10 (90%), after which it dropped. Helmets were much less frequently used by teenagers (14%), especially girls. Consistently, the share of head injuries increased as the children got older. Bicycle helmets were found to reduce all head injuries by 61% (95% confidence interval [CI], 10: +/- 10%) and AIS 2+ head injuries by 68% (95% CI, 12: +/- 12%). The effectiveness in reducing face injuries was lower (45% CI +/- 10% for all injuries and 54% CI +/- 32% for AIS2+ injuries).Conclusions: This study indicated that bicycle helmets effectively reduce injuries to the head and face. The results thus point to the need for actions aimed at increasing helmet use, especially among teenagers. Protective measures are necessary to further reduce injuries, especially to the upper extremities.

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

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

Bicycle crashes and sickness absence - a population-based Swedish register study of all individuals of working ages

BACKGROUND

In recent years, bicycle injuries have increased, yet little is known about the impact of such injures on sickness absence (SA) and disability pension (DP). The aim was to explore SA and DP among individuals of working ages injured in a bicycle crash.

METHOD

A nationwide register-based study, including all individuals aged 16-64 years and living in Sweden, who in 2010 had in- or specialized out-patient healthcare (including emergency units) after a bicycle crash. Information on age, sex, sociodemographics, SA, DP, crash type, injury type, and injured body region was used. We analyzed individuals with no SA or DP, with ongoing SA or full-time DP already at the time of the crash, and with new SA > 14 days in connection to the crash. Crude and adjusted odds ratios (OR) with 95% confidence intervals for new SA were estimated by logistic regression.

RESULTS

In total, 7643 individuals had healthcare due to a new bicycle crash (of which 85% were single-bicycle crashes). Among all, 10% were already on SA or full-time DP at the time of the crash, while 18% had a new SA spell. The most common types of injuries were external injuries (38%) and fractures (37%). The body region most frequently injured was the upper extremities (43%). Women had higher OR (1.40; 1.23-1.58) for new SA than men, as did older individuals compared with younger (OR 2.50; 2.02-3.09, for ages: 55-64 vs. 25-34). The injury types with the highest ORs for new SA, compared with the reference group external injuries was fractures (8.04; 6.62-9.77) and internal injuries (7.34; 3.67-14.66). Individuals with traumatic brain injury and injuries to the vertebral column and spinal cord had higher ORs for SA compared with other head, face, and neck injuries (2.72; 1.19-6.22 and 3.53; 2.24-5.55, respectively).

CONCLUSIONS

In this explorative nationwide study of new bicycle crashes among individuals of working ages, 18% had a new SA spell in connection to the crash while 10% were already on SA or DP. The ORs for new SA were higher among women, older individuals, and among individuals with a fracture.

Integrating Spatial and Temporal Approaches for Explaining Bicycle Crashes in High-Risk Areas in Antwerp (Belgium)

The majority of bicycle crash studies aim at determining risk factors and estimating crash risks by employing statistics. Accordingly, the goal of this paper is to evaluate bicycle–motor vehicle crashes by using spatial and temporal approaches to statistical data. The spatial approach (a weighted kernel density estimation approach) preliminarily estimates crash risks at the macro level, thereby avoiding the expensive work of collecting traffic counts; meanwhile, the temporal approach (negative binomial regression approach) focuses on crash data that occurred on urban arterials and includes traffic exposure at the micro level. The crash risk and risk factors of arterial roads associated with bicycle facilities and road environments were assessed using a database built from field surveys and five government agencies. This study analysed 4120 geocoded bicycle crashes in the city of Antwerp (CA, Belgium). The data sets covered five years (2014 to 2018), including all bicycle–motorized vehicle (BMV) crashes from police reports. Urban arterials were highlighted as high-risk areas through the spatial approach. This was as expected given that, due to heavy traffic and limited road space, bicycle facilities on arterial roads face many design problems. Through spatial and temporal approaches, the environmental characteristics of bicycle crashes on arterial roads were analysed at the micro level. Finally, this paper provides an insight that can be used by both the geography and transport fields to improve cycling safety on urban arterial roads.

Bicycle-related traumatic injury hospitalizations: six years descriptive analysis in Qatar

Background:

Bicycle riding is a widely practiced mode of transportation, commuting, competition, fitness and recreation. We aimed to describe the incidence, risk factors and outcomes of Bicycle-Related Traumatic Injury (BRTI) in a Middle Eastern country.

Methods:

Data were extracted from a prospectively collected trauma registry over a period of six years (2010- 2015) from the national trauma center. Demographics and clinical characteristics of patients, and outcomes were analyzed.

Results:

There were 150 patients with a mean age of 27.2±16.6 years, 98% were males, 86.6% were hit by a car and 8.7% died. The average annual incidence of BRTIs was 1.3 per 100,000 populations. The mean Glasgow Coma Score (GCS) and injury severity score (ISS) were12.7±4.0 and 13.6±9.8; respectively. Almost one-third of cases had an ISS of 9-15. The most commonly injured region was the head (47%) followed by a lower extremity (30%), chest (25%), upper extremity (21.3%), spine (20.7%), abdomen (18.7%) and (7%) pelvis.

Conclusions:

BRTI is relatively uncommon in Qatar; however, it is characterized by a distinct epidemiology with a considerable mortality. Young male nationals, recreational cyclists and expatriate young commuter cyclists comprise the majority of victims and should be the focus of primary prevention efforts. Complementary prevention should aim at enforcing helmet laws to reduce fatal head injuries, and educating motorists of safer practices around cyclists.

Crash histories, safety perceptions, and attitudes among Virginia bicyclists

INTRODUCTION

Cycling injury and fatality rates are on the rise, yet there exists no comprehensive database for bicycle crash injury data.

METHOD

Widely used for safety analysis, police crash report datasets are automobile-oriented and widely known to under-report bicycle crashes. This research is one attempt to address gaps in bicycle data in sources like police crash reports. A survey was developed and deployed to enhance the quality and quantity of available bicycle safety data in Virginia. The survey captures bicyclist attitudes and perceptions of safety as well as bicycle crash histories of respondents.

RESULTS

The results of this survey most notably show very high levels of under-reporting of bicycle crashes, with only 12% of the crashes recorded in this survey reported to police. Additionally, the results of this work show that lack of knowledge concerning bicycle laws is associated with lower levels of cycling confidence. Count model results predict that bicyclists who stop completely at traffic signals are 40% less likely to be involved in crashes compared to counterparts who sometimes stop at signals. In this dataset, suburban and urban roads with designated bike lanes had more favorable injury severity profiles, with lower percentages of severe and minor injury crashes compared to similar roads with a shared bike/automobile lane or no designated bike infrastructure.

Bicycle helmets - To wear or not to wear? A meta-analyses of the effects of bicycle helmets on injuries

A meta-analysis has been conducted of the effects of bicycle helmets on serious head injury and other injuries among crash involved cyclists. 179 effect estimates from 55 studies from 1989-2017 are included in the meta-analysis. The use of bicycle helmets was found to reduce head injury by 48%, serious head injury by 60%, traumatic brain injury by 53%, face injury by 23%, and the total number of killed or seriously injured cyclists by 34%. Bicycle helmets were not found to have any statistically significant effect on cervical spine injury. There is no indication that the results from bicycle helmet studies are affected by a lack of control for confounding variables, time trend bias or publication bias. The results do not indicate that bicycle helmet effects are different between adult cyclists and children. Bicycle helmet effects may be somewhat larger when bicycle helmet wearing is mandatory than otherwise; however, helmet wearing rates were not found to be related to bicycle helmet effectiveness. It is also likely that bicycle helmets have larger effects among drunk cyclists than among sober cyclists, and larger effects in single bicycle crashes than in collisions with motor vehicles. In summary, the results suggest that wearing a helmet while cycling is highly recommendable, especially in situations with an increased risk of single bicycle crashes, such as on slippery or icy roads.

Value of emergency department triage data to describe and understand patterns and mechanisms of cycling injuries

OBJECTIVE

To characterise patients presenting to EDs for a bicycle-related injury, identify contributing factors to the injuries and describe the data gaps.

METHODS

A retrospective study of bicycle-related injury presentations over the 5 year period 2010-2014 to two major metropolitan EDs. Data collected from the emergency presentation database consisted of patient demographics, presenting complaint, discharge diagnosis and details about the circumstances and mechanism of the accident.

RESULTS

Bicycle injuries (n = 4144) increased from 20.0 to 25.2 per 1000 injury presentations over 5 years. Patients were 80% male across all age groups and 35% of presentations occurred at the weekend. Fractures accounted for one-third (34%) of all injuries, while injuries to the upper extremities and head resulted in 36% and 19% of cases, respectively. Admission rate was 17%. The number of falls exceeded collisions (1611 vs 937), and in the 13.3% of the fall cases where documentation was present for which how the fall occurred, over half were attributed to bike handling errors. Information related to type of bicycle, accident location, type of activity, protective clothing worn (including helmets) and visibility aids was not recorded for over 95% of the cases.

CONCLUSION

Bicycle injuries carry a considerable burden to the ED and the incidence of presentations appears to be rising. The current triage data, designed to provide a rapid assessment for medical urgency, are limited to describing broad demographics, trends and causes.

Cycling injuries and alcohol

BACKGROUND

Most of the cycling accidents that occur in Finland do not end up in the official traffic accident statistics. Thus, there is minimal information on these accidents and their consequences, particularly in cases in which alcohol was involved. The focus of the present study is on cycling accidents and injuries involving alcohol in particular.

METHODS

Data on patients visiting the emergency department at North Kymi Hospital because of a cycling accident was prospectively collected for two years, from June 1, 2004 to May 31, 2006. Blood alcohol concentration (BAC) was measured on admission with a breath analyser. The severity of the cycling injuries was classified according to the Abbreviated Injury Scale (AIS).

RESULTS

A total of 217 cycling accidents occurred. One third of the injured cyclists were involved with alcohol at the time of visiting the hospital. Of these, 85% were males. A blood alcohol concentration of ≥ 1.2 g/L was measured in nearly 90% of all alcohol-related cases. A positive BAC result was more common among males than females (p < 0.001), and head injuries were more common among cyclists where alcohol was involved (AI) (60%) than among sober cyclists (29%) (p < 0.001). Two thirds (64%) of the cyclists with AI were not wearing a bicycle helmet. The figure for serious injuries (MAIS ≥ 3) was similar in both groups. Intoxication with an alcohol level of more than 1.5 g/L and the age of 15 to 24 years were found to be risk factors for head injuries. The mean cost of treatment was higher among sober cyclists than among cyclists with AI (€2143 vs. €1629), whereas in respect of the cost of work absence, the situation was the opposite (€1348 vs. €1770, respectively).

CONCLUSIONS

Cyclists involved with alcohol were, in most cases, heavily intoxicated and were not wearing a bicycle helmet. Head injuries were more common among these cyclists than among sober cyclists. As cycling continues to increase, it is important to monitor cycling accidents, improve the accident statistics and heighten awareness of the risks of head injuries when cycling under the influence of alcohol.

Where do bike lanes work best? A Bayesian spatial model of bicycle lanes and bicycle crashes

US municipalities are increasingly introducing bicycle lanes to promote bicycle use, increase roadway safety and improve public health. The aim of this study was to identify specific locations where bicycle lanes, if created, could most effectively reduce crash rates. Previous research has found that bike lanes reduce crash incidence, but a lack of comprehensive bicycle traffic flow data has limited researchers' ability to assess relationships at high spatial resolution. We used Bayesian conditional autoregressive logit models to relate the odds that a bicycle injury crash occurred on a street segment in Philadelphia, PA (n = 37,673) between 2011 and 2014 to characteristics of the street and adjacent intersections. Statistical models included interaction terms to address the problem of unknown bicycle traffic flows, and found bicycle lanes were associated with reduced crash odds of 48% in streets segments adjacent to 4-exit intersections, of 40% in streets with one- or two-way stop intersections, and of 43% in high traffic volume streets. Presence of bicycle lanes was not associated with change in crash odds at intersections with less or more than 4 exits, at 4-way stop and signalized intersections, on one-way streets and streets with trolley tracks, and on streets with low-moderate traffic volume. The effectiveness of bicycle lanes appears to depend most on the configuration of the adjacent intersections and on the volume of vehicular traffic. Our approach can be used to predict specific street segments on which the greatest absolute reduction in bicycle crash odds could occur by installing new bicycle lanes.

A problem of the safety of vulnerable road users in Montenegro

Research on the safety of vulnerable road users in Montenegro and in the European Union found that pedestrian fatality rates are the highest, followed by motorcyclists, and then cyclists. In the European Union, fatality rates are decreasing for all groups of vulnerable road users, while in Montenegro the fatality rate of pedestrians and cyclists is decreasing. The safety improvement for vulnerable road users is less successful than that for people in vehicles. Pedestrians in Montenegro are at the highest risk in the European Union. In Montenegro, pedestrians and cyclists are most vulnerable on the streets in the most developed settlements, while moped riders and motorcyclists are most vulnerable on the main roads. The implementation of control measures led to a turning point, and further improvement was obtained after implementing safety campaigns; for greater improvements, it will be necessary to establish local institutions for traffic safety management.

Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors

Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action "Towards safer bicycling through optimization of bicycle helmets and usage". The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting - including injury crashes that do not lead to hospitalization - justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.

Hazard perception training in young bicyclists improves early detection of risk: A cluster-randomized controlled trial

INTRODUCTION

Since child bicyclists are more likely to get involved in a traffic crash, there is a stringent need to provide child bicyclists with tailored interventions in order to enhance their capabilities to deal with the complexity of traffic situations. The current study therefore aimed to test the effectiveness of a hazard anticipation training in young bicyclists by means of eye tracking technology.

METHODS

A cluster-randomized controlled design was used in which participating schools were randomly assigned to the intervention or the control group. At first, a baseline hazard anticipation test was carried out in the intervention group (78 children; 9.56±0.38years of age) and the control group (46 children; 9.58±0.41years of age). Child bicyclists who participated in the intervention followed the training that consisted of two classroom sessions. In each session children were presented with video clips from the perspective of a bicyclist encountering various (potentially) dangerous traffic situations. Following the intervention, a post-test directly after the training and a retention test three weeks later were completed. The control group received the intervention after the retention test.

RESULTS

Trained child bicyclists were found to detect more hazards and reacted quicker compared to the control group that did not receive the training. However, the training did not result in improvements in anticipatory visual search behaviour.

CONCLUSION

Trained child bicyclists seemed to have developed a better processing regarding potential dangerous situations but were not able to 'see' the hazard sooner. The potential of a brief hazard anticipation training is discussed.

Hazard perception in young cyclists and adult cyclists

Child bicyclists are at greater risk to get involved in a traffic accident. Although hazard perception tests between inexperienced and experienced car drivers revealed significant differences in perceptual-cognitive skills, a similar test for bicyclists is not yet existent. Therefore this study aimed to compare visual search patterns and reaction times of child bicyclists and adult bicyclists utilizing a hazard perception test for cyclists. Seventy-five children and forty-one adults were presented with eleven video clips filmed from the perspective of the bicyclist. The participants were required to press a response button whenever they detected a hazardous situation. Children were found to have significantly delayed reaction times and time until the first fixation on the latent covert hazards compared to adults. The inefficient visual search patterns in children may be attributed to an immature visual system. However, the finding that children fixated later on the hazards and only responded to the covert latent hazards when they became salient indicate difficulties with identifying possible hazards. Altogether, the findings of this study suggest that children's situation awareness is dependent upon experience too, and not just maturation. Therefore, implications for training young bicyclists will be discussed.

Reading cyclist intentions: Can a lead cyclist's behaviour be predicted?

As a cyclist, it is essential to make inferences about the intentions of other road users in order to anticipate their behaviour. There are official ways for cyclists to communicate their intentions to other road users, such as using their arms to point in the intended direction of travel. However, in everyday traffic cyclists often do not use such active forms of communication. Therefore, other visual cues have to be used to anticipate (critical) encounters or events. During this study, 108 participants completed a video internet survey in which they predicted the intentions of a lead cyclist based on visible behaviour preceding a turning manoeuvre. When the lead cyclist approached the intersection, each video was stopped just before the cyclist initiated turning. Based on visual cues, the participants had to select which direction they thought the cyclist would go. After entering their prediction, they were asked how certain they were about their prediction and on which visible behaviour(s) each prediction was based. The results show that it is very hard to predict the direction of a turning cyclist based on visual cues before the turning manoeuvre is initiated. Exploratory regression analyses revealed that observable behaviours such as head movements and cycling speed were related to prediction accuracy. These results may be used to support cyclists in traffic interactions.

Road accidents involving bicycles: configurations and injuries

This study analyzed the most common types of accident involving bicycles and compared the frequency of injuries. The data source was the database of German In-Depth Accident Study (GIDAS). Cases consist of bicycles and their riders involved in accidents between 2000 and 2010. In most collisions, the bicycle impacted with a car. The percentage of injured bicyclists was higher in collisions with a heavy vehicle and decreased when the bicycle impacted with lighter vehicles. A high percentage of injured bicyclists in single accidents was observed; the most severe injury was more frequently to head and extremities. Accidents involving a car and a bicycle with the right of way in a bicycle path represented about 20% of involved and injured bicyclists. The ten most frequent configurations represented about 60% of involved and injured bicyclists. These results contribute to understand the dangerous scenarios for bicyclists and to suggest preventive actions.

Characteristics of bicycle crashes in an adolescent population in Flanders (Belgium)

INTRODUCTION

In regions where transportation is mainly motorized, air pollution and traffic congestion are rife. Active transportation such as cycling might be a solution but safety is a major concern. An efficient science based safety policy is needed. The aim of this paper is to analyze in depth the bicycle crash causes and characteristics in an adolescent population (14-18 yr).

METHODS

By using questionnaires for self-reported bicycle crashes, bicycle crash data were collected from insurance companies (January 2014-June 2015) and from schools (November 2013-March 2014). Six bicycle crash causes were predefined and possible differences between schools and insurance companies were analyzed.

RESULTS

Eighty-six school and 78 insurance registered crashes were analyzed. "Distraction of the cyclist" and "third party crossing a bicycle path failing to see the cyclist" are the main causes of bicycle crashes (both 29%). Bad (maintained) infrastructure accounted for 21% of the crash causes. Bicycle crashes reported at insurance companies needed significantly more medical attention and led to high absenteeism (57% at least one day of absenteeism). Only 21% of the bicycle crashes reported at insurance companies were also reported in the official police database.

CONCLUSION

The human factor was the main cause accounting for 79% of the crashes. Bicycle crashes involving a car accounted for 42% and single bicycle crashes accounted for 31% of the total number of crashes. From the bicycle crashes registered at insurance companies 21% was also registered in official police statistics. A combination of information, education and changing the bicycle specific environment might reduce the consequences of human errors more efficiently.

Development of cycling skills in 7- to 12-year-old children

OBJECTIVE

Cycling is a complex skill consisting of motor skills such as pedalling, braking, and steering. Because the ability to perform cycling skills is based on the age-related development of the child, experience and age-related reference values are of interest in light of customized testing and training.

METHODS

One hundred thirty-eight children from the second (7-8 years), fourth (9-10 years), and sixth (11-12 years) grades performed a practical bicycle test consisting of 13 test items with specific points of interest. Moreover, age at onset of cycling, cycling to and from school, independent mobility, and minutes cycling per week were estimated using a parental questionnaire.

RESULTS

It is found that cycling skills are strongly related to age with 11- to 12-year-old children outperforming 7- to 8-year-old children for 11 test items and 9- to 10-year-old children for 8 test items.

CONCLUSIONS

Next to age, age at onset of cycling also contributed to cycling skills. Therefore, our results suggest that cycling skills are associated with physical and mental maturation. Subsequently, age-related reference values are provided to customize testing and training.

Modeling and Optimization of Airbag Helmets for Preventing Head Injuries in Bicycling

Bicycling is the leading cause of sports-related traumatic brain injury. Most of the current bike helmets are made of expanded polystyrene (EPS) foam and ultimately designed to prevent blunt trauma, e.g., skull fracture. However, these helmets have limited effectiveness in preventing brain injuries. With the availability of high-rate micro-electrical-mechanical systems sensors and high energy density batteries, a new class of helmets, i.e., expandable helmets, can sense an impending collision and expand to protect the head. By allowing softer liner medium and larger helmet sizes, this novel approach in helmet design provides the opportunity to achieve much lower acceleration levels during collision and may reduce the risk of brain injury. In this study, we first develop theoretical frameworks to investigate impact dynamics of current EPS helmets and airbag helmets-as a form of expandable helmet design. We compared our theoretical models with anthropomorphic test dummy drop test experiments. Peak accelerations obtained from these experiments with airbag helmets achieve up to an 8-fold reduction in the risk of concussion compared to standard EPS helmets. Furthermore, we construct an optimization framework for airbag helmets to minimize concussion and severe head injury risks at different impact velocities, while avoiding excessive deformation and bottoming-out. An optimized airbag helmet with 0.12 m thickness at 72 ± 8 kPa reduces the head injury criterion (HIC) value to 190 ± 25 at 6.2 m/s head impact velocity compared to a HIC of 1300 with a standard EPS helmet. Based on a correlation with previously reported HIC values in the literature, this airbag helmet design substantially reduces the risks of severe head injury up to 9 m/s.