Deaths of cyclists in London 1985-92: the hazards of road traffic

Factors impacting bicyclist lateral position and velocity in proximity to commercial vehicle loading zones: Application of a bicycling simulator

There is little research on the behavioral interaction between bicycle lanes and commercial vehicle loading zones (CVLZ) in the United States. These interactions are important to understand, to preempt increasing conflicts between truckers and bicyclists. In this study, a bicycling simulator experiment examined bicycle and truck interactions. The experiment was successfully completed by 48 participants. The bicycling simulator collected data regarding a participant's velocity and lateral position. Three independent variables reflecting common engineering approaches were included in this experiment: pavement marking (L1: white lane markings with no supplemental pavement color, termed white lane markings, L2: white lane markings with solid green pavement applied on the conflict area, termed solid green, and L3: white lane markings with dashed green pavement applied on the conflict area, termed dashed green), signage (L1: No sign and L2: a truck warning sign), and truck maneuver (L1: no truck in CVLZ, L2: truck parked in CVLZ, and L3: truck pulling out of CVLZ). The results showed that truck presence does have an effect on bicyclist's performance, and this effect varies based on the engineering and design treatments employed. Of the three independent variables, truck maneuvering had the greatest impact by decreasing mean bicyclist velocity and increasing mean lateral position. It was also observed that when a truck was present in a CVLZ, bicyclists had a lower velocity and lower divergence from right-edge of bike lane on solid green pavement, and a higher divergence from the right-edge of bike lane was observed when a warning sign was present.

Looking forward to safer HGVs: The impact of mirrors on driver reaction times

Heavy Goods Vehicle (HGV) collisions are responsible for a disproportionate number of urban vulnerable road user casualties (VRU - cyclists and pedestrians). Blind-spots to the front and side of HGVs can make it difficult (sometimes impossible) to detect close proximity VRUs and may be the cause of some collisions. The current solution to this problem is to provide additional mirrors that can allow the driver to see into the blind-spots. However, keeping track of many mirrors requires frequent off-road glances which can be difficult to execute during demanding driving situations. One suggestion is that driving safety could be improved by redesigning cabs in order to reduce/remove blind-spot regions, with the aim of reducing the need for mirrors, and increasing detection rates (and thereby reducing collisions). To examine whether mirrors delay driver responses we created a series of simulated driving tasks and tested regular car drivers and expert HGV drivers. First we measured baseline reaction times to objects appearing when not driving ('Parked'). Participants then repeated the task whilst driving through a simulated town (primary driving tasks were steering, braking, and following directional signs): driving slowed reaction times to objects visible in mirrors but not to objects visible through the front windscreen. In a second experiment cognitive load was increased, this slowed RTs overall but did not alter the pattern of responses across windows and mirrors. Crucially, we demonstrate that the distribution of mirror RTs can be captured simply by the mirror's spatial position (eccentricity). These findings provide robust evidence that drivers are slower reacting to objects only visible in eccentric mirrors compared to direct viewing through the front windscreen.

Cyclists fatalities: Forensic remarks regarding 335 cases

A retrospective study was carried out on post-mortem examination data regarding 335 cyclists involved in fatal accidents along the period 1983-2012. The following variables were considered: temporal data (year, month, day of the week and hour of the day), circumstances of the accident, vehicles involved, victims' features (sex, age), pathological and toxicological findings, cause of death. Most victims were male (77.62%), with a mean age of 58 years. In most cases vehicles other than only bicycles were involved, more frequently cars, followed by heavy motor vehicles. Head was the most frequently body region involved in lethal injuries (65.37%); low extremities were the body district most frequently involved in non-lethal injuries (63.9%). This study confirmed the importance of using helmet; head protection should be a priority for bikers.

Circumstances and causes of fatal cycling crashes in the Czech Republic

OBJECTIVES

The circumstances and causes of death of 129 cyclists registered in the Olomouc and the Zlín regions, the Czech Republic, between 2005 and 2013 were the subject of this study.

METHODS

We analyzed the autopsy reports, where the principal cause of death was stated, and obtained a detailed description of the circumstances recorded by the police officers.

RESULTS

Eighty-three cases (64.3% of the set) were collisions involving a motor vehicle. The driver was the guilty party in 57 cases (68.7%) and the cyclist in the remaining 26 cases (31.3%). The most frequent cause of the crash was connected with right of way (29 cases). Cars were involved in 52 cases; heavy vehicles, including buses, in 26 cases; and motorcycles in 5 cases. Single-vehicle crashes consisted of 43 (33.3%) cases. We divided this group into 3 subgroups based on whether the particular case could be attributed to a cyclist having lost control of the bicycle (31 cases) or to other particular causes. Sixty-eight cases (52.7%) of fatal outcomes were directly linked to intracranial injuries. Multiple injuries were the principal cause of death in 19 cases (14.7%), followed by hemorrhagic traumatic shock (12 cases, 9.3%). Seventy-two (55.8%) cyclists died immediately after the crash and 23 (17.8%) cyclists died within a day of the accident.

CONCLUSIONS

Trucks were more dangerous to cyclists than cars at intersections, whereas cars were more dangerous on straight sections. The most important pattern was identified as a motor vehicle hitting a cyclist from behind on a straight road section. We identified a strong underestimation of natural death as a cause of cycling fatalities in the official police reports.

Health effects of the London bicycle sharing system: health impact modelling study

OBJECTIVE

To model the impacts of the bicycle sharing system in London on the health of its users.

DESIGN

Health impact modelling and evaluation, using a stochastic simulation model.

SETTING

Central and inner London, England.

DATA SOURCES

Total population operational registration and usage data for the London cycle hire scheme (collected April 2011-March 2012), surveys of cycle hire users (collected 2011), and London data on travel, physical activity, road traffic collisions, and particulate air pollution (PM2.5, (collected 2005-12).

PARTICIPANTS

578,607 users of the London cycle hire scheme, aged 14 years and over, with an estimated 78% of travel time accounted for by users younger than 45 years.

MAIN OUTCOME MEASURES

Change in lifelong disability adjusted life years (DALYs) based on one year impacts on incidence of disease and injury, modelled through medium term changes in physical activity, road traffic injuries, and exposure to air pollution.

RESULTS

Over the year examined the users made 7.4 million cycle hire trips (estimated 71% of cycling time by men). These trips would mostly otherwise have been made on foot (31%) or by public transport (47%). To date there has been a trend towards fewer fatalities and injuries than expected on cycle hire bicycles. Using these observed injury rates, the population benefits from the cycle hire scheme substantially outweighed harms (net change -72 DALYs (95% credible interval -110 to -43) among men using cycle hire per accounting year; -15 (-42 to -6) among women; note that negative DALYs represent a health benefit). When we modelled cycle hire injury rates as being equal to background rates for all cycling in central London, these benefits were smaller and there was no evidence of a benefit among women (change -49 DALYs (-88 to -17) among men; -1 DALY (-27 to 12) among women). This sex difference largely reflected higher road collision fatality rates for female cyclists. At older ages the modelled benefits of cycling were much larger than the harms. Using background injury rates in the youngest age group (15 to 29 years), the medium term benefits and harms were both comparatively small and potentially negative.

CONCLUSION

London's bicycle sharing system has positive health impacts overall, but these benefits are clearer for men than for women and for older users than for younger users. The potential benefits of cycling may not currently apply to all groups in all settings.

Deaths of cyclists in London: trends from 1992 to 2006

BACKGROUND

Cycling is an increasingly important mode of transport for environmental and health reasons. Cycling fatalities in London were previously investigated in 1994 using routinely collected data. Since then, there have been shifts in the modes of transport used, and in transport policies. We sought to replicate the previous work using data on cyclist deaths in London between 1992 and 2006, specifically investigating whether heavy goods vehicles continued to pose a threat.

METHODS

Observational study based on analysis of time series of police road casualties data, 1992 to 2006, in London, UK. The main outcome measures were cyclists killed in road traffic collisions. Poisson regression and chi-squared test for homogeneity were used to assess time effects. Travel flow data was then used to estimate annual fatality rates per 100,000 cyclists per kilometre.

RESULTS

From 1992 to 2006 there was a mean of 16 cycling fatalities per year (range 8-21). 146 deaths (60%) were in inner London and 96 in outer London. There was no evidence for a decline over time (p = 0.7) other than a pronounced dip in 2004 when there were 8 fatalities. Freight vehicles were involved in 103 of 242 (43%) of all incidents and the vehicle was making a left turn in over half of these (53%). The fatality rate ranged from 20.5 deaths in 1992 to 11.1 deaths in 2006 per 100,000 estimated cyclists per kilometre (rate ratio 0.54, 95% confidence interval 0.28 to 1.03).

CONCLUSIONS

There is little evidence fatality rates have fallen. Freight vehicles over 3.5 tonnes continue to present a disproportionate threat; they should be removed from urban roads and more appropriate means of delivery of essential goods found.

Injuries to pedal cyclists on New Zealand roads, 1988-2007

BACKGROUND

The risk of injury is one of the major barriers to engaging in cycling. We investigated exposure-based rates and profiles of traffic injuries sustained by pedal cyclists that resulted in death or hospital inpatient treatment in New Zealand, one of the most car dependent countries.

METHODS

Pedal cyclist traffic injuries were identified from the Mortality Collection and the National Minimum Dataset. Total time spent cycling was used as the measure of exposure and computed from National Household Travel Surveys. Analyses were undertaken for the periods 1988-91, 1996-99 and 2003-07 in relation to other major road users and by age, gender and body region affected. A modified Barell matrix was used to characterise the profiles of pedal cyclist injuries by body region affected and nature of injury.

RESULTS

Cyclists had the second highest rate of traffic injuries compared to other major road user categories and the rate increased from 1996-99 to 2003-07. During 2003-07, 31 injuries occurred per million hours spent cycling. Non-collision crashes (40%) and collisions with a car, pick-up truck or van (26%) accounted for two thirds of the cycling injuries. Children and adolescents aged under 15 years were at the highest risk, particularly of non-collision crashes. The rate of traumatic brain injuries fell from 1988-91 to 1996-99; however, injuries to other body parts increased steadily. Traumatic brain injuries were most common in collision cases whereas upper extremity fractures were most common in other crashes.

CONCLUSIONS

The burden of fatal and hospitalised injuries among pedal cyclists is considerable and has been increasing over the last decade. This underscores the development of road safety and injury prevention programmes for cyclists alongside the cycling promotion strategies.

Bicyclist fatalities in New York City: 1996-2005

OBJECTIVES

To describe bicyclist fatalities in a traffic-dense, urban environment.

METHODS

Multiple New York City (NYC) agencies provided information on bicyclist deaths. Fatality Analysis Reporting System (FARS) data were used to compare NYC's bicyclist fatality rate involving motor vehicles with rates in comparable urban centers.

RESULTS

Between 1996 and 2005, 225 bicyclists died in NYC. Most fatalities resulted from motor vehicle crashes (92%). Men in NYC had higher death rates than women, and no age group had higher risk. Most of NYC's bicyclist fatalities occurred at intersections (88%). Head injuries contributed to 77 percent of deaths; helmet use was rare (3%). Most fatal crashes (91%) involved motorist and bicyclist factors, such as inattention and unsafe speed. Alcohol was detected in 21 percent of bicyclists dying within 3 hours of a crash; motorist alcohol use was a contributing factor in 6 percent of crashes. Over half were on multi-lane roads (53%). Large vehicles were involved in 30 percent of crashes but comprise 5-17 percent of road vehicles. Bicyclist fatality rates involving motor vehicles in NYC were comparable to those of other cities.

CONCLUSION

Findings suggest the merits of multipronged efforts to prevent crashes and to improve bicyclist safety in NYC and in other dense, urban environments. Motorists and bicyclists should be made aware of the risks of alcohol use and the benefits of helmet-wearing. Road users should pay attention to traffic control measures and travel at safe speeds. Interventions that control traffic at intersections and on multilane streets, that dedicate and demarcate routes for motorists and cyclists, and that improve visibility, especially for large vehicles, warrant consideration.

Cycle helmets and road casualties in the UK

OBJECTIVES

Bicycle helmets have been advocated as a means of reducing injury among cyclists. This assertion, derived from a number of case controlled studies carried out in hospitals, conflicts with results from population level studies. In the Western countries where these case control studies have been performed, it appears that cycling morbidity is dominated by sports and leisure users. The generalizability of studies on helmet effectiveness in relation to utilitarian transport cycling is not clear. This study therefore considers population level data for reported road traffic injuries of cyclists and pedestrians.

METHODS

Generalized linear and generalized additive models were used to investigate patterns of pedestrian and cyclist injury in the UK based on the police reported "Stats 19" data. Comparisons have been made with survey data on helmet wearing rates to examine evidence for the effectiveness of cycle helmets on overall reported road casualties. While it must be acknowledged that police casualty reports are prone to under-reporting, particularly of incidents involving lower severity casualties the attractive feature of these data are that by definition they only concern road casualties.

RESULTS

There is little evidence in UK from the subset of road collisions recorded by the police corresponding to the overall benefits that have been predicted by the results of a number of published case controlled studies. In particular, no association could be found between differing patterns of helmet wearing rates and casualty rates for adults and children.

CONCLUSIONS

There is no evidence that cycle helmets reduce the overall cyclist injury burden at the population level in the UK when data on road casualties is examined. This finding, supported by research elsewhere could simply be due to cycle helmets having little potential to reduce the overall transport-related cycle injury burden. Equally, it could be a manifestation of the "ecological fallacy" where it could be conceived that the existence of various sub-groups of cyclists, with different risk profiles, may need to be accounted for in understanding the difference between predicted and realised casualty patterns.

Cycling: the risks

On average, 140 cyclists are killed each year on Britain’s roads and a further 22 785 injured. About a third of those injured are children. This review examines the nature and circumstances of cycling injuries and contrasts them with the risks associated with other modes of transport. It looks at the effectiveness of cycle helmet use and suggests other measures to best reduce cycling injuries.

Fatal truck-bicycle accident involving dragging for 45 km

Vehicle-bicycle accidents with subsequent dragging of the rider over long distances are extremely rare. The case reported here is that of a 16-year-old mentally retarded bike rider who was run over by a truck whose driver failed to notice the accident. The legs of the victim became trapped by the rear axle of the trailer and the body was dragged over 45 km before being discovered under the parked truck. The autopsy revealed that the boy had died from the initial impact and not from the dragging injuries which had caused extensive mutilation. The reports of the technical expert and the forensic pathologist led the prosecutor to drop the case against the truck driver for manslaughter.

Predictors of bicycle helmet usage among seniors

This study identified predictors of bicycle helmet usage in a sample of seniors in Mesa, Arizona. Participants reported: days/week bicycling, usual duration, where biking occurred, helmet ownership, bicycle accidents, injuries, and age and gender. Descriptive, non-parametric statistics, and regression analysis were utilized. Seventy-four females and 123 males completed the survey. The mean age was 70.7(7.2) years. Respondents biked a mean of 4.9(2.3) days per week and averaged 40.5 (32.5) minutes of riding per day. Eighty-two participants (41.6%) owned bicycle helmets and 55 (27.9%) were observed wearing helmets. Eighty-seven (44.2%) participants biked outside their retirement community and 25 (12.7%) reported an accident within the past year. Chi-square (2, N = 197) = 0.66, p = .72) indicated no differences in of male or female helmet usage. Those who rode outside the retirement communities (chi2(2, 197) = 22.6, p = .001) were more likely to wear helmets than counterparts. Logistic regression found age to be a predictor of bicycle helmet usage.

Differential profile of facial injuries among mountainbikers compared with bicyclists

BACKGROUND

Bicyclists and mountainbikers are prone to facial trauma. In the current study, we present a large series of cycling-related sports trauma to the face in an effort to identify the injury pattern among mountainbikers compared with bicyclists.

METHODS

The medical records of a single pediatric and adult Level I trauma center were evaluated from January 1, 1991, through October 31, 1996. All admissions with injuries caused by cycling-related sports were reviewed, analyzed, and compared according to age and sex distributions, causes of accidents, injury types, frequency, and localization of fractures and associated injuries. The injury types were divided into three categories: fractures, dentoalveolar trauma, and soft-tissue injuries.

RESULTS

Five hundred sixty-two injured bicyclists (10.3% of all trauma patients) were registered at the Department of Oral and Maxillofacial Surgery, University of Innsbruck, Austria, during the study period, accounting for 31% of all sports-related or 48.4% of all traffic collisions, respectively. The review of the patient records revealed especially more severe injury profiles in 60 mountainbikers, with 55% facial bone fractures, 22% dentoalveolar trauma, and 23% soft-tissue injuries, compared with 502 street cyclists showing 50.8% dentoalveolar trauma, 34.5% facial bone fractures, and 14% soft-tissue lesions. The dominant fracture site in bicyclists was the zygoma (30.8%), whereas mountainbikers sustained an impressive 15.2% Le Fort I, II, and III fractures. Condyle fractures were more common in bicyclists, with 18.8% opposing 10.8% in mountainbikers.

CONCLUSION

Appropriate design of helmets with faceguards will reduce the incidence of facial injuries caused by cycling-related accidents and incentives are needed for making helmet use compulsory for all cyclists, particularly for mountainbikers.

The pattern of injury in fatal pedal cycle accidents and the possible benefits of cycle helmets

OBJECTIVE

To establish the number of fatal pedal cycle accidents occurring in the Sheffield and Barnsley area, UK, and to investigate the possible benefits of helmet wearing by cyclists.

DESIGN

All medicolegal investigations into fatal road traffic accidents in the areas of Sheffield and Barnsley (total population 757,300) were reviewed to identify cases in which pedal cyclists had died. The necropsy reports of the cases were compared with those of an equal number of controls (pedestrians and motor vehicle occupants) which were matched by sex, age and year of death.

RESULTS

28 deaths occurred in the last 15 years giving a mortality of 0.25/100,000 per annum, which is lower than the rate for the UK as a whole (0.43/100,000), but in five cases the accidents which eventually led to death occurred outside the area under study. These deaths represented 3.3% of road traffic deaths between 1979 and 1993. Over 80% of both cases and controls had severe head injuries, but the controls had suffered more fatal injuries to other parts of the body. None of the cyclists had worn helmets and, in order to assess the maximum possible benefit of helmet wearing, it was assumed that a helmet would have saved all those who only had head injuries. It was found that helmets might have saved 14 lives in 15 years. A similar calculation based on the controls suggests that if all pedestrians and vehicle occupants had worn helmets, 175 lives might have been saved in the same period.

CONCLUSIONS

There is no justification for compelling cyclists to wear helmets without taking steps to improve the safety of all road users.

Cyclist road deaths in London 1985-1992: drivers, vehicles, manoeuvres and injuries

We used coroners' records to investigate the fatal accidents of cyclists recorded on death certificates in London during 1985-1992. There were 124 deaths: 68 cyclists were injured in London and 56 injured in the "home counties" around London and died in London hospitals. The cyclists' ages were from 8-88, and 70% were male; the drivers were aged 17-74, and 96% were male. Of the 108 vehicles involved, 53 were cars (including one parked) and 40 heavy goods vehicles (HGVs) (including 14 large lorries and 18 articulated lorries), 5 light goods vehicles, 5 buses and coaches and 5 motorcycles. Fatal accidents occurred with a wide range of manoeuvres; of vehicles turning left (driving is on the left in the U.K.), 14 out of 15 were HGVs. Accidents were most often on 2 lane roads and one half were near a road junction. Law violations were recorded in half the accidents; alcohol intoxication contributed only rarely. While injuries to the head were the commonest reported direct cause of death, Inner London deaths were frequently due to multiple injuries. The study confirms the serious danger to cyclists (particularly women) in Inner London from large and articulated lorries, causing death from multiple injuries.