Motorcycle-related injuries in the United Arab Emirates

Objectives

To study the anatomical distribution, severity, outcome, and age by nationality of hospitalized motorcycle-related injured patients in Al-Ain, United Arab Emirates so as to improve preventive measures.

Methods

All motorcycle riders involved in a road traffic collision and admitted to Al-Ain Hospital for more than 24 h or who died in hospital after arrival were studied. Patient data were retrieved from Al-Ain Hospital Trauma Registry. Data had been prospectively collected during four and half years (March 2003–October 2007). Demography of patients, Glasgow Coma Scale (GCS), Injury Severity Score (ISS), Hospital stay, mortality, nationality, time, day of week, and month of occurrence were analyzed.

Results

There were 95 patients (93 males). Mean (SD) age was 29.8 (11.5) years. 35% were United Arab Emirates (UAE) nationals. Upper limbs were most frequently involved (54%) followed by lower limbs (48%), head (41%), and face (30%). On arrival at hospital, median (range) ISS was 4.5 (1–36) and median (range) GCS was 15 (3–15). Mean (range) hospital stay was 8.8 (1–79) days. 14 patients (15%) were admitted to the Intensive Care Unit. In-hospital mortality was 6%. UAE national victims were significantly younger and had more abdominal injuries than expatriates, who had lower limb injuries.

Conclusions

The most common mechanism of motorcycle crashes was hitting a moving vehicle. Young UAE national motorcyclists are at a higher risk of being injured compared with non UAE nationals. This may be due to risk-taking behavior of young motorcyclists who are mainly riding for leisure. Extremities were the most common injured body region. Severe head injury was the main cause of death. This signifies the need for effective application of motorcycle helmet law in the UAE along with other preventive measures that might include increasing the licensing age.     

Injury prediction in a side impact crash using human body model simulation

Background

Improved understanding of the occupant loading conditions in real world crashes is critical for injury prevention and new vehicle design. The purpose of this study was to develop a robust methodology to reconstruct injuries sustained in real world crashes using vehicle and human body finite element models.

Methods

A real world near-side impact crash was selected from the Crash Injury Research and Engineering Network (CIREN) database. An average sedan was struck at approximately the B-pillar with a 290 degree principal direction of force by a lightweight pickup truck, resulting in a maximum crush of 45 cm and a crash reconstruction derived Delta-V of 28 kph. The belted 73-year-old midsized female driver sustained severe thoracic injuries, serious brain injuries, moderate abdominal injuries, and no pelvic injury. Vehicle finite element models were selected to reconstruct the crash. The bullet vehicle parameters were heuristically optimized to match the crush profile of the simulated struck vehicle and the case vehicle. The Total Human Model for Safety (THUMS) midsized male finite element model of the human body was used to represent the case occupant and reconstruct her injuries using the head injury criterion (HIC), half deflection, thoracic trauma index (TTI), and pelvic force to predict injury risk. A variation study was conducted to evaluate the robustness of the injury predictions by varying the bullet vehicle parameters.

Results

The THUMS thoracic injury metrics resulted in a calculated risk exceeding 90% for AIS3+ injuries and 70% risk of AIS4+ injuries, consistent with her thoracic injury outcome. The THUMS model predicted seven rib fractures compared to the case occupant's 11 rib fractures, which are both AIS3 injuries. The pelvic injury risk for AIS2+ and AIS3+ injuries were 37% and 2.6%, respectively, consistent with the absence of pelvic injury. The THUMS injury prediction metrics were most sensitive to bullet vehicle location. The maximum 95% confidence interval width for the mean injury metrics was only 5% demonstrating high confidence in the THUMS injury prediction.

Conclusions

This study demonstrates a variation study methodology in which human body models can be reliably used to robustly predict injury probability consistent with real world crash injury outcome.     

Impact of road safety interventions on traffic-related occupational injuries in Spain, 2004–2010

Objectives

To evaluate the impact of road safety interventions, including the penalty point system (PPS) and the reformed Spanish penal code (RPC), on traffic-related occupational injuries in Spain.

Methods

The study design was an interrupted time-series with a comparison group. The study group had traffic-related, occupational injuries incurred during working and commuting hours; the comparison group had non-traffic-related injuries incurred at the work site. A negative binomial regression model was used to determine the relative risk (RR) of sustaining occupational injuries for the post-intervention periods compared to the non-intervention period.

Results

Non-fatal, traffic-related injuries did not significantly change after the PPS and RPC implementations, except for those occurred in commuting hours, which increased significantly after the PPS. On the other hand, after the RPC, fatal, traffic-related injuries decreased significantly during working hours (0.79; 95%CI 0.65 to 0.97) and commuting hours (RR: 0.63; 95%CI:0.56 to 0.72), although fatal, non-traffic-related injuries also decreased at the work site.

Conclusions

Road safety interventions did not clearly affect traffic-related occupational injuries in Spain. Specific occupational risk factors could influence the occurrence of those injuries.     

Association between cannabis use and non-traffic injuries

Background

This study aimed to assess the association between cannabis use and unintended non-fatal injuries other than those caused by road crashes.

Methods

Cross-sectional data were collected from a nationwide sample of 27,934 subjects surveyed in 2005 in Spain: 14,699 persons aged 15–34 years and 13,235 aged 35–64 years. Logistic regression was used to obtain odds ratios (OR) between patterns of cannabis use and frequency of non-traffic injuries, adjusted for sociodemographic factors and for the use of alcohol, tobacco and other drugs.

Results

Cannabis use in the last 12 months was associated with a higher frequency of injuries (OR = 1.4; 95% CI: 1.2–1.7). The OR in older adults (35–64 year age group) was 1.8 and 1.3 in younger people (15–34 year age group). The strongest associations found were between weekly use of cannabis and injuries from knocks and bumps (OR = 5.1; 95% CI 2.9–8.9) and those occurring outside work (OR = 3.0; 95% CI 1.8–4.9) in the older adult population.

Conclusion

Although our analysis did not control for behavioural factors, cannabis use is independently associated with an increased frequency of non-traffic injuries, especially in the older adult population. These associations emphasise the need to carry out longitudinal studies addressing the causal links between cannabis use and unintended injuries.     

Trends in head injuries associated with mandatory bicycle helmet legislation targeting children and adolescents

Background

Bicycling related head injuries (HIs) can be severe. Helmet use reduces head injury risk; however, there are few controlled studies of the effect of helmet legislation. We conducted this study to investigate changes in HIs after bicycle helmet legislation targeting those <18 in Alberta, Canada in 2002.

Methods

Bicyclist and pedestrian (control) HI rates and HIs as a proportion of all injuries were compared for the three years (1999–2001) before and four years (2003–2006) after bicycle helmet legislation in three age groups (children: <13, adolescents: 13–17, and adults: 18+).

Results

There were 41,270 ED visits and 2782 hospitalizations for bicyclists and 9836 ED visits and 2029 hospitalizations for pedestrians (excluding the legislation year 2002). The rate of ED HIs declined for child bicyclists and child pedestrians, while the rate of non-HIs declined in adult bicyclists and child pedestrians. The rate of hospitalized HIs declined in child bicyclists and all ages of pedestrians while non-HI rates declined for child and adult pedestrians. Non-HI rates for adolescent and adult bicyclists increased. After adjusting for sex and location, the proportion of ED bicycle HIs declined by 9% (APR = 0.91; 95% CI: 0.86, 0.95) in children, was unchanged among adolescents and increased in adults (APR = 1.08; 95% CI: 1.01, 1.15). The proportion of bicycle HI related hospitalizations decreased by 30% (APR = 0.70; 95% CI: 0.55, 0.90) in children, 36% (APR = 0.64; 95% CI: 0.49, 0.84) in adolescents and 24% (APR = 0.76; 95% CI: 0.63, 0.91) in adults. There were no observed changes in the proportion of pedestrian HIs resulting in ED visits or hospitalizations.

Interpretation

Our data indicate significant declines in the proportion of child bicyclist ED HIs and child, adolescent and adult bicyclist HI hospitalizations. This is in contrast to no significant trends in the proportion of ED or hospitalized HIs among pedestrians and the unexpected increases in the proportion of ED HIs for adult bicyclists. Comparing bicyclist and pedestrian trends in the proportion of child and adolescent HIs suggests a bicycle helmet legislation effect.     

A few seconds to have an accident,a long time to recover: Consequences for road accident victims from the ESPARR cohort 2 years after the accident

Objective

The aim of the present study was to describe the consequences of a road accident in adults, taking account of the type of road user, and to determine predictive factors for consequences at 2 years.

Design

Prospective follow-up study.

Methods

The cohort was composed of 1168 victims of road traffic accidents, aged ≥16 years. Two years after the accident, 912 victims completed a self-administered questionnaire. Weighted logistic regression models were implemented to compare casualties still reporting impact related to the accident versus those reporting no residual impact. Five outcomes were analysed: unrecovered health status, impact on occupation or studies, on familial or affective life, on leisure or sport activities and but also the financial difficulties related to the accident.

Results

46.1% of respondents were motorised four-wheel users, 29.6% motorised two-wheel (including quad) users, 13.3% pedestrians (including inline skate and push scooter users) and 11.1% cyclists. 53.3% reported unrecovered health status, 32.0% persisting impact on occupation or studies, 25.2% on familial or affective life, 46.9% on leisure or sport activities and 20.2% still had accident-related financial difficulties. Type of user, adjusted on age and gender, was linked to unrecovered health status and to impact on leisure or sport activities. When global severity (as measured by NISS) was integrated in the previous model, type of user was also associated with impact on occupation or studies. Type of user was further associated with impact on occupation or studies and on leisure or sport activities when global severity and the sociodemographic data obtained at inclusion were taken into account. It was not, however, related to any of the outcomes studied here, when the models focused on the injured body region. Finally, type of road user did not seem, on the various predictive models, to be related to financial difficulties due to the accident or to impact on familial or affective life.

Conclusions

Overall, victims were affected by their accident even 2 years after it occurred. The severity of lesions induced by the accident was the main predictive factor. However, considering lesion as intermediary factors between the accident and the recovery status at 2 year post-accident, impact on health status was lower for cyclists than M4W users or M2W users.     

The influence of demographic factors,processing speed and short-term memory on Iranian children's pedestrian skills

Objectives

Young children, children from lower socioeconomic status and boys have the highest risk of pedestrian injury. This study examined the relationship between cognition and specific pedestrian skills of these groups of children in Iran.

Methods

180 Iranian children aged 7 and 11 years from lower- and higher-socioeconomic status backgrounds participated in the study. A task to identify safe and dangerous road crossing sites and to plan a safe route to cross a road was administered to measure pedestrian skills. Coding and Digit Span subscales of WISC-R were administered to assess processing speed and short-term memory.

Results

Identifying safe/dangerous road crossing-sites and safe route-construction abilities increased with age. Boys scored higher than girls when identifying road crossing sites but did not differ to girls in route-construction. Lower socioeconomic status children scored higher than higher socioeconomic status children on the route-construction task. Girls from lower socioeconomic status backgrounds scored lowest on the identifying safe/dangerous sites task and girls from higher socioeconomic status backgrounds scored lowest on the route construction task. Speed of processing was a significant predictor for identifying crossing sites and socioeconomic status was a significant predictor for route-construction.

Conclusions

Pedestrian skills are complex and influenced by age, gender, socioeconomic status and cognitive development. Results are discussed in relation to child pedestrian safety research in Iran and road safety education for children.     

Fitness-to-drive after mild traumatic brain injury: Mapping the time trajectory of recovery in the acute stages post injury

Introduction

Little is known about the trajectory of recovery in fitness-to-drive after mild traumatic brain injury (mTBI). This means that health-care professionals have limited evidence on which to base recommendations to this cohort about driving.

Objective

To determine fitness-to-drive status of patients with a mTBI at 24 h and two weeks post injury, and to summarise issues reported by this cohort about return to driving.

Method

Quasi-experimental case-control design. Two groups of participants were recruited: patients with a mTBI (n = 60) and a control group with orthopaedic injuries (n = 60). Both groups were assessed at 24 h post injury on assessments of fitness-to-drive. Follow-up occurred at two weeks post injury to establish driver status.

Main Measures

Mini mental state examination, occupational therapy-drive home maze test (OT–DHMT), Road Law Road Craft Test, University of Queensland-Hazard Perception Test, and demographic/interview form collected at 24 h and at two weeks.

Results

At the 24 h assessment, only the OT–DHMT showed a difference in scores between the two groups, with mTBI participants being significantly slower to complete the test (p = 0.01). At the two week follow-up, only 26 of the 60 mTBI participants had returned to driving. Injury severity combined with scores from the 24 h assessment predicted 31% of the variance in time taken to return to driving. Delayed return to driving was reported due to: “not feeling 100% right” (n = 14, 23%), headaches and pain (n = 12, 20%), and dizziness (n = 5, 8%).

Conclusion

This research supports existing guidelines which suggest that patients with a mTBI should not to drive for 24 h; however, further research is required to map factors which facilitate timely return to driving.     

A prospective study of children aged <16 years in motor vehicle collisions in Norway: Severe injuries are observed predominantly in older children and are associated with restraint misuse

Objective

The implementation of the compulsory wearing of seat belts (SBs) for children and improvements in child restraint systems have reduced the number of deaths and severe injuries among children involved in motor vehicle (MV) collisions (MVCs). Establishing the characteristics predictive of such injuries may provide the basis for targeted safety campaigns and lead to a further reduction in mortality and morbidity among children involved in MVCs. This study performed a multidisciplinary investigation among child occupants involved in MVCs to elucidate injury mechanisms, evaluate the safety measures used and determine the characteristics that are predictive of injury.

Methods

A prospective study was conducted of all child occupants aged <16 years involved in severe MVCs in south-eastern Norway during 2009–2013. The exterior and interior of the MVs were investigated and the injured children were medically examined. Supplementary information was obtained from witnesses, the crash victims, police reports, medical records and reconstructions. Each case was reviewed by a multidisciplinary team to assess the mechanism of injury.

Results

In total, 158 child occupants involved in 100 MVCs were investigated, of which 27 (17%) exhibited Abbreviated Injury Scale (AIS) scores of 2+ injuries and 15 (9%) exhibited AIS 3+ injuries. None of the children died. Of those with AIS 2+ injuries (n = 27), 89% (n = 24) were involved in frontal impact collisions and 11% (3/27) were involved in side impacts. Multivariate analysis revealed that restraint misuse, age, the prevailing lighting conditions and ΔV were all independently correlated with AIS 2+ injuries. Safety errors were found in 74% (20/27) of those with AIS 2+ injuries and 93% (14/15) of those with AIS 3+ injuries. The most common safety error was misuse of restraints, and in particular loose and/or improperly positioned SBs.

Conclusion

The risk of injury among child occupants is significantly higher when the child occupants are exposed to safety errors within the interior of the vehicle. Future campaigns should focus on the prevention of restraint misuse and unsecured objects in the passenger compartment or boot.     

Severe bicycling injury risk factors in children and adolescents: A case–control study

Background

Bicycling is the most common cause of sports and recreation injury in children and adolescents; yet, there is limited evidence on the factors associated with severe bicycling injuries in youth.

Methods

Case–control study of injured bicyclists less than 18 years old seen in seven emergency departments (EDs) from May 2008 to October 2010. Cases were bicyclists hospitalized after their ED visit (severe injury). Controls were bicyclists seen and discharged from the ED (non-severe injury). Personal, environmental, and crash characteristics were collected by interview. Injury data were collected from medical charts. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression were used to estimate the odds of hospitalization associated with risk factors. Multiple imputation techniques were employed to address missing data.

Results

There were 1470 participants including 119 cases. Those ages 13–17 had the highest proportion (23%) of severe injuries resulting from motor vehicle [MV] collision. In models including age, sex and MV collision, being male (OR: 2.02; 95% CI: 1.21–3.38), not wearing a helmet (OR: 2.18; 95% CI: 1.43–3.31) and MV collision (OR: 3.91; 95% CI: 2.26–6.78) were significant risk factors for severe injury. Riding on a paved surface (OR: 0.63; 95% CI: 0.41–0.97) and utilitarian (school, work) bicycling (OR: 0.44; 95% CI: 0.2–0.94) decreased injury risk. Results were similar, apart from utilitarian bicycling (OR: 0.49; 95% CI: 0.22–1.06), after imputation for missing data.

Conclusion

Bicycle–MV collisions increase severe injury risk in youth, and adolescents are often injured in these events. This suggests separating bicyclists from MVs or traffic calming strategies could improve safety.     

The relationship between vehicle roof crush and head,neck and spine injury in rollover crashes

Background

It is well established that rollover crashes are associated with a higher risk of serious injury and death than other types of crashes. Some of the most serious injuries that can result from a rollover crash are those to the head, neck and spine. The mechanism of injury to these body parts in a rollover is a matter of dispute in the literature. Some authors have concluded that the magnitude of vehicle roof deformation or vertical roof crush resulting from a rollover crash is not causally associated with head and neck injury severity, while others offer support for a causal association between roof crush and the degree of injury. A better understanding of the cause of serious injuries resulting from rollover crashes is important for improving injury prevention.

Methods

This study utilized data from the National Automotive Sampling System – Crashworthiness Data System (NASS-CDS) for the years 1997 through 2007. Both cross-sectional and matched case–control designs along with a new composite injury metric termed the Head, Neck and Spine New Injury Severity Score (HNS-NISS) were used to analyze these data.

Results

The cross-sectional analysis demonstrated a 64% (95% CI: 26–114%) increase in the odds of a life-threatening injury as estimated by the HNS-NISS with every 10 cm of increased roof crush. The results of the matched case–control analysis demonstrated a 44% (95% CI: 8–91%) increase in the odds of sustaining any injury to the head, neck or spine with every 10 cm increase in roof crush.

Conclusion

These results lend statistical support to a causal association between roof crush and head, neck and spine injury severity. Though they do not constitute definitive proof, they do contradict previously published theories suggesting that roof deformation is unrelated to such injuries.     

Comparing the effects of age,BMI and gender on severe injury (AIS 3+) in motor-vehicle crashes

Background

The effects of age, body mass index (BMI) and gender on motor vehicle crash (MVC) injuries are not well understood and current prevention efforts do not effectively address variability in occupant characteristics.

Objectives

(1) Characterize the effects of age, BMI and gender on serious-to-fatal MVC injury. (2) Identify the crash modes and body regions where the effects of occupant characteristics on the numbers of occupants with injury is largest, and thereby aid in prioritizing the need for human surrogates that represent different types of occupant characteristics and adaptive restraint systems that consider these characteristics.

Methods

Multivariate logistic regression was used to model the effects of occupant characteristics (age, BMI, gender), vehicle and crash characteristics on serious-to-fatal injuries (AIS 3+) by body region and crash mode using the 2000–2010 National Automotive Sampling System (NASS-CDS) dataset. Logistic regression models were applied to weighted crash data to estimate the change in the number of annual injured occupants with AIS 3+ injury that would occur if occupant characteristics were limited to their 5th percentiles (age ≤ 17 years old, BMI ≤ 19 kg/m²) or male gender.

Results

Limiting age was associated with a decrease in the total number of occupants with head [8396, 95% CI 6871–9070] and thorax injuries [17,961, 95% CI 15,960–18,859] across all crash modes, decreased occupants with spine [3843, 95% CI 3065–4242] and upper extremity [3578, 95% CI 1402–4439] injuries in frontal and rollover crashes and decreased abdominal [1368, 95% CI 1062–1417] and lower extremity [4584, 95% CI 4012–4995] injuries in frontal impacts. The age effect was modulated by gender with older females more likely to have thorax and upper extremity injuries than older males. Limiting BMI was associated with 2069 [95% CI 1107–2775] fewer thorax injuries in nearside crashes, and 5304 [95% CI 4279–5688] fewer lower extremity injuries in frontal crashes. Setting gender to male resulted in fewer occupants with head injuries in farside crashes [1999, 95% CI 844–2685] and fewer thorax [5618, 95% CI 4212–6272], upper [3804, 95% CI 1781–4803] and lower extremity [2791, 95% CI 2216–3256] injuries in frontal crashes. Results indicate that age provides the greater relative contribution to injury when compared to gender and BMI, especially for thorax and head injuries.

Conclusions

Restraint systems that account for the differential injury risks associated with age, BMI and gender could have a meaningful effect on injury in motor-vehicle crashes. Computational models of humans that represent older, high BMI, and female occupants are needed for use in simulations of particular types of crashes to develop these restraint systems.     

Supervisor vs. employee safety perceptions and association with future injury in US limited-service restaurant workers

Objectives

Many studies have found management commitment to safety to be an important construct of safety climate. This study examined the association between supervisor and employee (shared and individual) perceptions of management commitment to safety and the rate of future injuries in limited-service restaurant workers.

Methods

A total of 453 participants (34 supervisors/managers and 419 employees) from 34 limited-service restaurants participated in a prospective cohort study. Employees’ and managers’ perceptions of management commitment to safety and demographic variables were collected at the baseline. The survey questions were made available in three languages: English, Spanish, and Portuguese. For the following 12 weeks, participants reported their injury experience and weekly work hours. A multivariate negative binomial generalized estimating equation model with compound symmetry covariance structure was used to assess the association between the rate of self-reported injuries and measures of safety perceptions.

Results

There were no significant relationships between supervisor and either individual or shared employee perceptions of management commitment to safety. Only individual employee perceptions were significantly associated with future employee injury experience but not supervisor safety perceptions or shared employee perceptions.

Conclusion

Individual employee perception of management commitment to safety is a significant predictor for future injuries in restaurant environments. A study focusing on employee perceptions would be more predictive of injury outcomes than supervisor/manager perceptions.     

Fatal crash involvement of unlicensed young drivers: County level differences according to material deprivation and urbanicity in the United States

Objectives

This study assessed the association between county level material deprivation and urbanization with fatal road traffic crashes involving young unlicensed drivers in the United States (US).

Background

Road traffic crashes have been positively associated with area deprivation and low population density but thus far few studies have been concerned specifically with young drivers, especially those that are unlicensed.

Methods

A county material deprivation index was derived from the Townsend Material Deprivation Index, with variables extracted from the US Census (2000). An urbanicity scale was adapted from the US Department of Agriculture's Rural–Urban Continuum Codes (2003). Data on fatal crashes involving a young unlicensed driver during a seven-year period (2000–2006; n = 3059) were extracted from the Fatality Analysis Reporting System. The effect of deprivation and urbanicity on the odds of the occurrence of at least one fatal crash at the county level was modeled by conditional and unconditional logistic regression.

Results

The conditional model found a positive association between material deprivation and a fatal crash involving a young unlicensed driver (OR = 1.19, 95% CI 1.17, 1.21). The interaction between urbanicity and material deprivation was negatively associated in suburban counties for fatal crashes (OR = 0.92, 95% CI 0.90, 0.95).

Conclusions

An association with material deprivation and the likelihood of a fatal crash involving a young unlicensed driver is a new finding. It can be used to inform specific county-level interventions and promote state licensing policies to provide equity in young people's mobility regardless of where they live.     

Inexperience and risky decisions of young adolescents,as pedestrians and cyclists,in interactions with lorries,and the effects of competency versus awareness education

Background

Road injuries are a prime cause of death in early adolescence. Often road safety education (RSE) is used to target risky road behaviour in this age group. These RSE programmes are frequently based on the assumption that deliberate risk taking rather than lack of competency underlies risk behaviour. This study tested the competency of 10–13 year olds, by examining their decisions – as pedestrians and cyclists – in dealing with blind spot areas around lorries. Also, the effects of an awareness programme and a competency programme on these decisions were evaluated.

Method

Table-top models were used, representing seven scenarios that differed in complexity: one basic scenario to test the identification of blind spot areas, and 6 traffic scenarios to test behaviour in traffic situations of low or high task complexity. Using a quasi-experimental design (pre-test and post-test reference group design without randomization), the programme effects were assessed by requiring participants (n = 62) to show, for each table-top traffic scenario, how they would act if they were in that traffic situation.

Results

On the basic scenario, at pre-test 42% of the youngsters identified all blind spots correctly, but only 27% showed safe behaviour in simple scenarios and 5% in complex scenarios. The competency programme yielded improved performance on the basic scenario but not on the traffic scenarios, whereas the awareness programme did not result in any improvements. The correlation between improvements on the basic scenarios and the traffic scenarios was not significant.

Conclusions

Young adolescents have not yet mastered the necessary skills for safe performance in simple and complex traffic situations, thus underlining the need for effective prevention programmes. RSE may improve the understanding of blind spot areas but this does not ‘automatically’ transfer to performance in traffic situations. Implications for the design of RSE are discussed.     

On-road bicycle facilities and bicycle crashes in Iowa, 2007–2010

Purpose

An average of 611 deaths and over 47,000 bicyclists are injured in traffic-related crashes in the United States each year. Efforts to increase bicycle safety are needed to reduce and prevent injuries and fatalities, especially as trends indicate that ridership is increasing rapidly. The objective of this study was to evaluate the effect of bicycle-specific roadway facilities (e.g., signage and bicycle lanes) in reducing bicycle crashes.

Methods

We conducted a case site-control site study of 147 bicycle crash-sites identified from the Iowa Department of Transportation crash database from 2007 to 2010 and 147 matched non-crash sites. Control sites were randomly selected from intersections matched to case sites on neighborhood (census block group) and road classification (arterial, feeder, collector, etc.). We examined crash risk by any on-road bicycle facility present and by facility type (pavement markings--bicycle lanes and shared lane arrows, bicycle-specific signage, and the combination of markings and signage), controlling for bicycle volume, motor vehicle volume, street width, sidewalks, and traffic controls.

Results

A total of 11.6% of case sites and 15.0% of controls had an on-road bicycle facility. Case intersections had higher bicycle volume (3.52 vs. 3.34 per 30 min) and motor vehicle volume (248.77 vs. 205.76 per 30 min) than controls. Our results are suggestive that the presence of an on-road bicycle facility decreases crash risk by as much as 60% with a bicycle lane or shared lane arrow (OR = 0.40, 95% CI = 0.09–1.82) and 38% with bicycle-specific signage (OR = 0.62, 95% CI = 0.15–2.58).

Conclusions

Investments in bicycle-specific pavement markings and signage have been shown to be beneficial to traffic flow, and our results suggest that they may also reduce the number of bicycle-motor vehicle crashes and subsequent injuries and fatalities. As a relatively low-cost traffic feature, community considerations for further implementation of these facilities are justified.