Bicycle Injuries Research Articles

Advancing healthy cities through safer cycling: An examination of shared lane markings

Abstract To advance healthy transportation via increased bicycling, cities combat one of the primary barriers to such cycling – traffic safety concerns – through the provision of various bicycle treatments. Shared lane markings (more commonly known as “sharrows”) are an increasingly common treatment utilized to improve bicyclist safety. While past research confirms that sharrows may effectively influence spacing and other operational measures, the impact on actual safety outcomes remains unsubstantiated due to a lack of dooring-related bicycle crash data. Fortunately, the city of Chicago instituted a program to collect dooring crash data in 2010. Thus, the purpose of this research is to longitudinally examine the association between sharrows and bicyclist injuries by combining traditional crash data with dooring-related crash data. To perform this examination, we divide Census block groups in Chicago into three categories based on what bicycle treatment was installed between the years 2011 and 2014: (i) those block groups with no bicycle facilities installed; (ii) those with only sharrows installed; or (iii) those with only bicycle lanes (standard, buffered, and/or protected) installed. Negative binomial regressions and Kruskal–Wallis tests suggest that block groups with only sharrows installed experienced the largest increase in bicyclist injury rates, with exposure being accounted for through levels of bicycle commuter activity. This relationship held true for overall crashes as well as for dooring-related crashes. These findings raise concerns regarding the safety effectiveness of sharrows as used by the City of Chicago during the study period and should be a call for more research on the subject in a variety of different contexts using various exposure metrics.

Pancreatic injury due to blunt abdominal trauma in children

The diagnosis and management of pediatric pancreatitis is often difficult. Blunt abdominal trauma is one of the most common causes of pancreatitis in childhood. This is a review of patients with blunt pancreatic trauma. Medical records of all children with blunt pancreatic trauma who were admitted to our clinic between July 2007 and December 2017 were analyzed retrospectively. There were 17 patients (7 girls, 10 boys) with a mean age of of 9.89±2.57 years (range, 3-14 years). The time from trauma to admittance to the clinic was mean 17±21.43 days (range, 0-63 days). The mechanism of injury was bicycle injuries in 7 (41.66%), a fall from height in 6 (35.29%), motor vehicle accidents in 3 (17.64%), and a fall from a horse in 1 (5.88%). All patients had serum pancreatic amylase elevation on admission (average, 1002.71±966.36 IU/L; range, 116-3163 IU/L). All the childen were initially managed non-operatively. In 8 patients (52.94%) the traumatic pancreatitis was complicated by development of a pseudocyst. The average diameter of the pseudocyst was 11.5±3.45 cm. The pseudocysts were resolved in 5 cases with percutaneous ultrasonography-guided fluid drainage and the remaining 3 required open surgery (2 cystogastrostomy, 1 surgical drainage). The average length of hospital stay was 18±15.91 days (range, 2–48 days). There were no deaths and no complications in any patients. Non-operative management of traumatic pancreatitis in the absence of complete duct transection is safe in children. Percutaneous drainage of traumatic pancreatic pseudocysts can be used as an effective and useful treatment option.

Child Bicyclist Perspectives on Danger and Injury Circumstances in the Built Environment

Danger perception and the built environment are associated with injury risk in adult bicyclists, but limited research exists related to child bicyclists. Our pilot study describes child bicyclist perspectives on safety in the built environment. Participants were children who came to the Alberta Children's Hospital emergency department with a bicycling injury sustained on public property. Research team members interviewed participants about their injury circumstances (n=26). This research is based on thematic analysis of their responses to the open-ended interview questions. The risks children perceived were obstructions, debris, grade, visibility, and risky behavior. Fear of perceived danger in the environment influenced participants' bicycling experiences. The results inform child-contextual understanding of the built environment.

Farm injury resulting in hospital admission: a review of farm work and non-farm work-related injury

ABSTRACT INTRODUCTIONOccupational health on farms is important because farms are not only workplaces where agriculture workers are vulnerable to high injury and fatality rates, they are also homes where families and visitors undertake a variety of activities that can result in injury. AIMTo profile and describe injuries requiring hospital admission that occurred on farms, both for injuries related to farming activities and injuries unrelated to farm work in the Midland region of New Zealand. METHODSA review of anonymised prospectively collected Midland trauma registry data from 1 July 2012 to 30 June 2018 was undertaken. Cases include unintentional injuries occurring on a farm. Non-major injuries are included to better quantify the trauma burden. RESULTSIn total, 2303 hospital admissions met the study criteria. Non-major injury accounted for 93.1% of events and 45.0% of injuries occurred during farming activities. Five people died in hospital; all injured while undertaking farm work. Males made up 84.8% of farm work and 70.9% of non-farm work injuries. Horse riding had the highest number of injuries, with off-road motorcycles, livestock, falls and quad bike injuries comprising the most common injury activities and mechanisms. Farming-related major injuries commonly involved quad bikes, non-traffic vehicles and motorcycles. Farmers in the Districts of Waitomo, Rotorua, Waipa and Taupō had the highest standardised hospitalisation rates. DISCUSSIONThe nature of farms and farming exposes people to different risks from the risks people in urban areas are exposed to. Injury prevention efforts should remain on work-related farming injuries, but also encompass the high number of injuries that are not related to farm work but happening on farms.

Identifying high-risk built environments for severe bicycling injuries

Introduction: This study is aimed at filling part of the knowledge gap on bicycling safety in the built environment by addressing two questions. First, are built environment features and bicyclist injury severity correlated; and if so, what built environment factors most significantly relate to severe bicyclist injuries? Second, are the identified associations varied substantially among cities with different levels of bicycling and different built environments? Methods: The generalized ordered logit model is employed to examine the relationship between built environment features and bicyclist injury severity. Results: Bicyclist injury severity is coded into four types, including no injury (NI), possible injury (PI), evident injury (EI), and severe injury and fatality (SIF). The findings include: (a) higher percentages of residential land and green space, and office or mixed use land are correlated with lower probabilities of EI and SIF; (b) land use mixture is negatively correlated with EI and SIF; (c) steep slopes are positively associated with bicyclist injury severity; (d) in areas with more transit routes, bicyclist injury is less likely to be severe; (e) a higher speed limit is more likely to correlate with SIF; and (f) wearing a helmet is negatively associated with SIF, but positively related to PI and EI. Practical applications: To improve bicycle safety, urban planners and policymakers should encourage mixed land use, promote dense street networks, place new bike lanes in residential neighborhoods and green spaces, and office districts, while avoiding steep slopes. To promote bicycling, a process of evaluating the risk of bicyclists involving severe injuries in the local environment should be implemented before encouraging bicycle activities.

Trends in All-terrain Vehicle Injuries From 2000 to 2015 and the Effect of Targeted Public Safety Campaigns.

All-terrain vehicles (ATVs) represent a notable portion of orthopaedic injuries presenting to emergency departments (EDs) in the United States. Public awareness campaigns have targeted these injuries, and this study sought to examine the effect of the 2007 American Academy of Orthopaedic Surgeons public safety campaign on ATV use. The United States Consumer Product Safety Commission National Electronic Injury Surveillance System (NEISS) was used to obtain national estimates of ATV and dirt bike injuries for the years 2000 to 2015. ED visits resulting from ATV injuries and dirt bike injuries were identified using NEISS product codes (ie, 3285-3287, 3296, and 5036). Patient demographics, injury-related data, and total annual case numbers were estimated. Chi-square tests and logistic regression were used for comparative analyses as appropriate. All statistical analyses were performed using SAS statistical software v.9.4 (SAS Institute). Statistical significance was set at P < 0.05 a priori. Beginning in 2000, the incidence of ATV injuries consistently increased over time and peaked in 2007 (54.1/100,000 people). Since 2007, the incidence of ATV injuries has consistently decreased (33.7/100,000 people in 2015). The frequency of ATV injuries differed significantly (P < 0.001) by age group, with children aged 14 to 17 years experiencing the highest incidence of ATV injury (2.8× national average). ATV injuries were also more common in males (2.7× national average; P < 0.001). The most common injuries were contusions and abrasions (25.3%), fractures (24.5%), and lacerations (11.4%). The decreased rate of ATV injury beginning in 2007 did not differ significantly (P = 0.81) from a comparative decrease in dirt bike-related injuries. This study provides the most current data on ATV injuries presenting to EDs in the United States. The rate of ATV-related injuries has steadily decreased since 2007, which corresponds to the American Academy of Orthopaedic Surgeons public awareness campaign. However, the reasons for this decrease are likely multifactorial. Children aged 14 to 17 years are at high risk of ATV-related injuries, with orthopaedic injuries accounting for a notable proportion.

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

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

Surgical outcomes of pancreaticoduodenal injuries in children

To examine surgical outcomes of children with pancreaticoduodenal injuries at a Quaternary Level I pediatric trauma center. We queried a prospectively maintained trauma database of a level one pediatric trauma center for all cases of pancreatic and/or duodenal injury from 2002 to 2017. Analysis was conducted using JMP 13.1.0. 170 children presented with pancreatic and/or duodenal injury. 13 (7.7%) suffered a combined injury and this group forms the basis for this report with mean ISS of 22.8 (± 15.1), RTS2 of 6.4(± 2.1), and median age of 6.6 (1.3-13.5) years. Child abuse (31%) and bicycle injuries (23%) were the most common mechanisms. 8/13 (61.5%) required operative intervention. Higher AAST pancreatic and duodenal injury grade (2.9 vs. 1.2, p = 0.05 and 3.6 vs. 1.4, p = < 0.01), lower RTS2 (7.84 vs. 5.49, p < 0.01), and lower GCS (9.6 vs. 15, p = 0.03) predicted operative intervention. 6/8 (75%) undergoing surgery survived to discharge with only (2/6) survivors suffering postoperative complications. Both mortalities were secondary to severe traumatic brain injury. Surgical management of complex pancreaticoduodenal injury is an uncommon traumatic event that is associated with high injury severity, but survival occurs in most scenarios.

Duration of sickness absence following a bicycle crash, by injury type and injured body region: A nationwide register-based study

In recent years, bicycle injuries have increased but little is known about the relation of such injures to sickness absence (SA). The aim of this study was to investigate duration of SA > 14 days after a bicycle crash, in general and by injury type and injured body region. A population-based study was conducted, including all individuals living in Sweden, aged 16-64 years, who in 2009-2011 had in-or specialized outpatient medical care due to a new injury from a bicycle crash (n = 22,045), excluding those already on SA or full-time disability pension at the time of the crash. Crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) for a new SA were estimated by logistic regression. In total, 4387 (20%) had new SA in connection to the crash. SA was most common among individuals aged 55-64 years (32%), and more common among women (23%) than men (18%). Fractures was the injury type with the highest OR for SA across all durations, but highest for 30-89 days (8.09; CI 6.30-10.39). Spine and back was the body region with the highest OR for SA >= 90 days (11.98; CI 7.38-19.46), followed by Traumatic Brain Injuries (6.64; CI 4.01-10.98), and injuries to lower extremities (5.28; CI 3.58-7.78). For 235 individuals (5%) the SA spell lasted >= 180 days. Among those cases, the most commonly injured body regions were lower leg (21%) followed by shoulder and upper arm (17%), and Traumatic Brain Injuries (15%). In conclusion, the duration of SA varied with type of injury and injured body region. Among the very long SA spells, common injuries were injuries to the lower leg, to the shoulder and upper arm, and traumatic brain injuries.

Pediatric Electric Bicycle Injuries: The Experience of a Large Urban Tertiary Care Pediatric Hospital.

Electric bicycles (E-bikes) are one of a wide range of light electric vehicles that provide convenient local transportation and attractive recreational opportunities. The aim of this study was to report E-bike-related injuries in children presenting to a trauma center. Retrospective observational study, from December 2014 to November 2015, which included all pediatrics patients admitted to the emergency department with an injury related to E-bike use, was performed. A total of 97 E-bike injuries presented to the emergency department during this period. Mean age of E-bikers was 13.7 years (range, 7.5-16 years). Injuries to the head and the upper and the lower extremities were the most common. Thirteen patients (15%) were admitted, and 4 underwent surgery. Children are mainly injured as riders when using E-bikes. There is a need for regulation regarding the use of E-bikes to enhance the safety of both bikers and other road and pavement users.

Study on the Orthopedic Characteristics of Bicycle Injury Patients

Study on the Orthopedic Characteristics of Bicycle Injury Patients

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.

Pediatric emergency department visits for pedestrian and bicyclist injuries in the US

BackgroundDespite reductions in youth pedestrian and bicyclist deaths over the past two decades, these injuries remain a substantial cause of morbidity and mortality for children and adolescents. There is a need for additional information on non-fatal pediatric pedestrian injuries and the role of traumatic brain injury (TBI), a leading cause of acquired disability.MethodsUsing a multi-year national sample of emergency department (ED) records, we estimated annual motorized-vehicle related pediatric pedestrian and bicyclist (i.e. pedalcyclist) injury rates by age and region. We modeled in-hospital fatality risk controlling for age, gender, injury severity, TBI, and trauma center status.ResultsED visits for pediatric pedestrian injuries declined 19.3% (95% CI 16.8, 21.8) from 2006 to 2012, with the largest decreases in 5-to-9 year olds and 10-to-14 year olds. Case fatality rates also declined 14.0%. There was no significant change in bicyclist injury rates.TBI was implicated in 6.7% (95% CI 6.3, 7.1) of all pedestrian and bicyclist injuries and 55.5% (95% CI 27.9, 83.1) of fatalities. Pedestrian ED visits were more likely to be fatal than bicyclist injuries (aOR = 2.4, 95% CI 2.3, 2.6), with significant additive interaction between pedestrian status and TBI.ConclusionsTBI in young pedestrian ED patients was associated with a higher risk of mortality compared to cyclists. There is a role for concurrent clinical focus on TBI recovery alongside ongoing efforts to mitigate and prevent motor vehicle crashes with pedestrians and bicyclists. Differences between youth pedestrian and cycling injury trends merit further exploration and localized analyses, with respect to behavior patterns and interventions. ED data captures a substantially larger number of pediatric pedestrian injuries compared to crash reports and can play a role in those analyses.

Mountain Biking Injuries.

With the increasing popularity of mountain biking, also known as off-road cycling, and the riders pushing the sport into extremes, there has been a corresponding increase in injury. Almost two thirds of acute injuries involve the upper extremities, and a similar proportion of overuse injuries affect the lower extremities. Mountain biking appears to be a high-risk sport for severe spine injuries. New trends of injury patterns are observed with popularity of mountain bike trail parks and freeride cycling. Using protective gear, improving technical proficiency, and physical fitness may somewhat decrease the risk of injuries. Simple modifications in bicycle-rider interface areas and with the bicycle (bike fit) also may decrease some overuse injuries. Bike fit provides the clinician with postural correction during the sport. In this review, we also discuss the importance of race-day management strategies and monitoring the injury trends.

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.

Epidemiology of clavicle fractures in a level 1 trauma center in Belgium.

In the last 10years, there has been an increasing tendency toward operative fixation of clavicle fractures. In this retrospective analysis, we will demographically assess all patients who sustained a clavicle fracture and were treated in our university hospital between 2004 and 2014. We retrospectively updated our database and analyzed all adult patients who were diagnosed with a clavicle fracture in our hospital. The following parameters were included in the database: age, gender, Robinson classification, date of trauma, injury mechanism, time until surgery, and reason for delayed surgery. Descriptive statistics were used to describe differences between patient groups and linear regression was performed to identify trends over time. 667 patients were included for analysis. The mean age was 43±17.7years. The majority of clavicle fractures occurred due to bicycle injuries (35.3%) and these increased from 2004 until 2014 (r = 0.738, R²=0.545, p = 0.009). Patients with a midshaft clavicle fracture were increasingly treated primarily surgically (r = 0.928, R²=0.861, p < 0.0001). There was an increased ratio of delayed surgery in relation to age from the age of 16 (9.1%) until the age of 70years (37.2%). There is an increasing number of fractures sustained by bicycle accidents and an increasing number of patients undergoing operative treatment. Middle-aged patients more often had delayed surgery compared with young adult patients. This could be due to an increased activity level of the elder population and the concomitant demand for a faster return to activities. III, retrospective comparative study.

How bicycle level of traffic stress correlate with reported cyclist accidents injury severities: A geospatial and mixed logit analysis

Transportation agencies need efficient methods to determine how to reduce bicycle accidents while promoting cycling activities and prioritizing safety improvement investments. Many studies have used standalone methods, such as level of traffic stress (LTS) and bicycle level of service (BLOS), to better understand bicycle mode share and network connectivity for a region. However, in most cases, other studies rely on crash severity models to explain what variables contribute to the severity of bicycle related crashes. This research uniquely correlates bicycle LTS with reported bicycle crash locations for four cities in New Hampshire through geospatial mapping. LTS measurements and crash locations are compared visually using a GIS framework. Next, a bicycle injury severity model, that incorporates LTS measurements, is created through a mixed logit modeling framework. Results of the visual analysis show some geospatial correlation between higher LTS roads and “Injury” type bicycle crashes. It was determined, statistically, that LTS has an effect on the severity level of bicycle crashes and high LTS can have varying effects on severity outcome. However, it is recommended that further analyses be conducted to better understand the statistical significance and effect of LTS on injury severity. As such, this research will validate the use of LTS as a proxy for safety risk regardless of the recorded bicycle crash history. This research will help identify the clustering patterns of bicycle crashes on high-risk corridors and, therefore, assist with bicycle route planning and policy making. This paper also suggests low-cost countermeasures or treatments that can be implemented to address high-risk areas. Specifically, with the goal of providing safer routes for cyclists, such countermeasures or treatments have the potential to substantially reduce the number of fatalities and severe injuries.

The Conspicuity Benefits of Dynamic and Static Bicycle Taillights at Night

A total of 729 bicyclist fatalities and approximately 50,000 bicyclist injuries were reported in the United States in 2014. Of the bicyclist fatalities, roughly 50% involved crashes that occurred at civil twilight or after dark (National Center for Statistics and Analysis, 2016). Also regarding bicyclist fatalities, Hutchinson and Lindsay (2009) found that the majority of bicyclists’ deaths resulted from collisions where the cyclists were hit from behind, especially at night, after investigating Australian bicycle/motor vehicle crashes. In addition, Bil, Bilovaa, & Muller, (2010) found that the highest percentages of cyclists’ fatalities occurred on straight road segments (23%) and curved road segments (16%) after analyzing patterns found in 5428 cyclists/motor vehicle collisions in the Czech Republic.Bicycle taillights have been found to enhance nighttime conspicuity (for a review, see Kwan & Mapstone, 2004). However, there are several gaps in the relevant literature, such as whether there is an optimal ...

An Open-Road Study of the Daytime Conspicuity Benefits of Fluorescent Bicyclist Apparel (Extended Abstract)

According to a 2016 NHTSA report (National Center for Statistics and Analysis, 2016) approximately 50,000 bicyclist injuries and 729 bicyclist fatalities were reported in the United States in the year 2014, with most crashes between motor vehicles and bicycles occuring during daylight hours. Most collisions between motor vehicles and bicyclists involve the bicyclist being struck from behind (Hutchinson &amp; Lindsay, 2009; Kim, Kim, Ulfarsson, &amp; Porrello, 2007). For this reason, it is important that bicyclists be sufficiently conspicuous to drivers who are approaching from behind. There has been a recent surge in research that applies basic perceptual science to make vulnerable road users more easily noticed by drivers. For example, humans’ perceptual sensitivity to biological motion (or “biomotion”; Johansson, 1973) can be used to enhance the conspicuity of pedestrians at night (for a review, see Tyrrell, Wood, Owens, Whetsel-Borzendowski, &amp; Stafford-Sewall, 2016). Similar findings, using either retroreflective tape or LEDs, have been found to apply to cyclists’ conspicuity as well (e.g., Kwan &amp; Mapstone, 2004; Wood, et al., 2012; Costa, et al., 2017). Taken together, the existing evidence makes it clear that efforts to enhance the conspicuity of both pedestrians and bicyclists – possibly including fluorescent apparel in daylight – are most effective when capitalizing on drivers’ perceptual sensitivity to biomotion. As such, this project explored the potential value of using fluorescent apparel strategically to make bicyclists more conspicuous to drivers during daylight hours. Specifically, we examined the influence of four different clothing configurations on the distances at which participants recognize the bicyclist wearing them. Methods. Visually healthy observers (N=186; mean age = 18.7 years) searched for bicyclists while a researcher drove them along a pre-determined route on public roads. Experimenters instructed participants to press a button on a numeric keypad each time they were confident that they recognized any person “on or with” a bicycle, who was “stopped or moving,” and who was “in or near the roadway.” Approximately seven minutes into their trip, participants encountered an experimenter wearing one of four outfits, pedaling (75 - 90 rpm) on a stationary bicycle on a sidewalk to the right of the roadway while facing away from the approaching vehicle. Experimenters delivered instructions to participants in such a way that was designed to limit participants’ expectancy that they would encounter a planted/scripted researcher on a bicycle during their trip. Participants’ button presses initiated a timer on the laptop computer operated by an experimenter in the back-seat of the research vehicle. The back-seat experimenter then stopped the timer once the test vehicle passed the test bicyclist. The elapsed time was used to calculate each participant’s response distance ( distance = speed × time). This technique has been used in numerous on-road pedestrian conspicuity experiments, and its accuracy has been verified for stationary roadway stimuli (e.g., Fekety, Edewaard, Stafford-Sewall, &amp; Tyrrell, 2016; Whetsel-Borzendowski, Stafford-Sewall, Rosopa, &amp; Tyrrell, 2015). After passing the experimenter bicyclist, the participants were informed that data collection had ended. Participants were then interviewed and debriefed while being driven back to the starting location. Each experimental session lasted approximately 30 minutes. Results. We performed a one-way between-subjects analysis of covariance (ANCOVA) to test the significance of the effects of clothing configuration on the response distances. The main effect of clothing was statistically significant, F(3,120) = 16.072, η2 = .287, p &lt; .001. Thus, the participants’ response distances significantly varied among the four clothing configurations. Post-hoc pairwise comparisons (Bonferroni) revealed that that a fluorescent yellow jersey did not significantly improve the cyclist’s conspicuity relative to a black jersey. However when the cyclist paired the fluorescent jersey with fluorescent yellow leggings, participants responded from a distance 3.3x farther than an identical outfit with black leggings. Discussion. The finding that fluorescent yellow leggings can provide a dramatic enhancement to bicyclist conspicuity is, we believe, a consequence of highlighting the bicyclist’s pedaling motion. The rhythmic up-down movements of a cyclist’s lower legs uniquely specify a pedaling motion that is visually distinct from, for example, a pedestrian walking or jogging. Further, considerable research has identified that highlighting a cyclist’s biological motion can provide powerful conspicuity enhancements. Thus fluorescent leggings can offer a powerful and low-tech tool for enhancing bicyclists’ daytime conspicuity.

Determinants of bicyclist injury severities in bicycle-vehicle crashes: A random parameters approach with heterogeneity in means and variances

This paper investigates risk factors that significantly contribute to the injury severity of bicyclists in bicycle/motor-vehicle crashes while systematically accounting for unobserved heterogeneity within the crash data. Using the data from Los Angeles over a seven-year period (January 1, 2010 to December 31, 2016) a random parameters multinomial logit model of bicyclist-injury severity, with heterogeneity in parameter means and variances, is estimated to explore the effects of a wide range of variables on bicyclist injury-severity outcomes. Model estimation results show that many factors potentially affect the likelihood of severe injuries in bicycle/motor-vehicle crashes including bicyclist and driver race and gender, alcohol-impaired bicyclists or drivers, older bicyclists, riding or driving on the wrong side of road, drivers’ unsafe speeding, bicyclist not wearing helmet, and so on. The findings of this research point toward the need to further study the contributing factors on the bicyclist injury severities.