Bicycle Accidents Research Articles

Advancements in Bicycle Safety: Integrating Control Sensors and Artificial Intelligence for Enhanced Airbag Innovation

Abstract: Motorcycle safety is a critical concern in traffic systems worldwide. This paper introduces a novel approach to enhancing rider safety through the integration of airless tires and advanced airbag systems, underpinned by artificial intelligence (AI) and control sensors. Airless tires contribute to vehicle stability by eliminating the risk of sudden deflation, while AI-driven airbag systems promise dynamic protection for riders during collisions. The study begins with an analysis of airless tire technology, emphasizing its impact on motorcycle stability and safety. It then transitions to the development of motorcyclespecific airbag systems, which utilize AI to process sensor data and make real-time decisions regarding airbag deployment. The effectiveness of these systems is validated through crash simulation tests and impact force measurements, demonstrating a substantial reduction in injury severity. Challenges such as cost, user acceptance, and technical constraints are thoroughly examined. The paper concludes with a discussion on future trends, including the potential for AI to predict and prevent accidents before they occur, thereby setting a new standard for motorcycle safety.

A dual-network structured poly (m-phenylene isophthalamide) nanofiber separator with Li6.4La3Zr1.4Ta0.6O12 for dendrite-free and high-safety lithium-metal batteries

Separator plays an important role in improving the long-term cycle stability and safety performance of high-energy–density lithium-metal batteries (LMBs). Herein, a robust thermotolerant separator is prepared by one-step electrospinning technique, combing fluorinated poly (m-phenylene isophthalamide) nanofibers with Li6.4La3Zr1.4Ta0.6O12 (LLZTO), a fast ionic conductor. The synergistically incorporated poly (vinylidene fluoride-co-hexafluoropropylene) and LLZTO trigger off the formation of a fancy dual-network structure with high porosity and well-distributed nanopores, in which ultrafine secondary nanonets are tightly bound with three-dimensional nanofiber scaffold. LLZTO can not only provide sufficient Li+ migration channels, but also immobilize free anions to strengthen ionic transmission. Moreover, this nanofiber separator possesses high mechanical strength, excellent thermal stability and desirable electrolyte affinity. It can gel liquid electrolyte well, leading to high tLi+, homogenized Li+ flux and uniform Li deposition. Consequently, LMBs with this dual-network structured nanofiber separator deliver satisfactory cycle stability and high C-rate capability. This contribution provides new insights into the design and development of high-quality nanofiber separators for dendrite-free and high-safety LMBs.

Self-Catalyzed Growth of Co4N and N-Doped Carbon Nanotubes toward Bifunctional Cathode for Highly Safe and Flexible Li-Air Batteries.

The practical application of high-energy density lithium-oxygen (Li-O2) batteries is severely impeded by the notorious cycling stability and safety, which mainly comes from slow kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at cathodes, causing inferior redox overpotentials and reactive lithium metal in flammable liquid electrolyte. Herein, a bifunctional electrode, a safe gel polymer electrolyte (GPE), and a robust lithium anode are proposed to alleviate above problems. The bifunctional electrode is composed of N-doped carbon nanotubes (N-CNTs) and Co4N by in situ chemical vapor deposition self-catalyzed growth on carbon cloth (N-CNTs@Co4N@CC). The self-supporting, binder-free N-CNTs@Co4N@CC electrode has a strong and stable three-dimensional (3D) interconnected conductive structure, which provides interconnectivity between the active sites and the electrode to promote the transfer of electrons. Furthermore, the N-CNT-intertwined Co4N ensures efficient catalytic activity. Hence, the electrode demonstrates improved electrochemical properties even under a large current density (2000 mA g-1) and long cycling operation (250 cycles). Moreover, a highly safe and flexible rechargeable cell using the 3D N-CNTs@Co4N@CC electrode, GPE, and robust lithium anode design has been explored. The open circuit voltage is stable at ∼3.0 V even after 9800 cycles, which proves the mechanical durability of the integrated GPE cell. The stable cable-type Li-air battery was demonstrated to stably drive the light-emitting diodes (LEDs), highlighting the reliability for practical use.

Promoting (Safe) Young-User Cycling in Russian Cities: Relationships among Riders’ Features, Cycling Behaviors and Safety-Related Incidents

Background: Promoting cycling, walking and other ‘active’ transportation means continues to be a shared guideline in urban planning, closely aligned with the Sustainable Development Goals of the United Nations. Nonetheless, young cyclists’ safety figures and their potential contributors, including behavioral issues, remain an ongoing concern for researchers, practitioners, and policymakers. Aim: This study aimed to analyze both risky and protective riding patterns of young Russian cyclists in relation to cycling safety factors using the Cycling Behavior Questionnaire (CBQ). Methods: This study used the data provided by 374 young Russian cyclists, aged M = 21.6 (SD = 4.8) years, who responded to an electronic survey on cycling behavior and safety outcomes. Results: Beyond demographic characteristics, the key road rule knowledge and risk perception of young cyclists were significantly associated with their self-reported cycling behaviors. Although both traffic violations and riding errors were negatively correlated with safety incidents, predictive analyses show that errors (though not violations) play a predictive role in young cyclists’ safety-related incidents. Conversely, positive cycling behaviors have been shown to be significant reducers of riding crash likelihood. Conclusion: The results of this study support the idea that addressing key issues such as risk perception, road rule knowledge and protective riding habits, while also targeting risky behaviors on the road, could enhance cycling safety outcomes. Additionally, these findings offer valuable insights into understanding the factors contributing to riding risks and crashes among young cyclists, particularly in the context of the increasing need to promote safer and more sustainable urban mobility in a country with a still young cycling culture.

Recent advances in separator design for lithium metal batteries without dendrite formation: Implications for electric vehicles

Electric vehicle (EV) technology addresses the challenge of reducing carbon and greenhouse gas emissions. The power battery, which serves as the energy source for EVs, directly impacts their driving range, maximum speed, and service life. Considering the high energy density requirements for future EVs, lithium metal anodes possess several advantages such as high theoretical capacity, high energy and power density, and low electrochemical reduction potential which enable them to be a promising material for next-generation batteries. However, lithium metal anodes suffer from short cycle life and safety concerns due to the formation of dendritic and moss-like metal deposits that impede battery performance and reliability. This review will feature the recent advancement of functional separators to tackle these challenges. Firstly, this review presents a comprehensive review of the growth mechanism of lithium dendrites and delineates the underlying processes leading to battery failure. This aims to deepen understanding, which serves as a fundamental basis for classifying separators. Then, according to the growth of lithium dendrites and the failure process of lithium metal batteries, namely lithium-ion nucleation, growth of lithium dendrites, penetration of lithium dendrites into the separator, thermal runaway and even failure of the battery, four types of functional separators for different stages are proposed. The functions of these types of separators are to prevent the nucleation of lithium ions and regulate the uniform deposition of lithium ions, detect and eliminate dendrites, increase the mechanical strength of the separator and enhance the thermal stability and flame-retardancy of the separators, respectively. Finally, the recent advances of the above strategies are reviewed and discussed, existing critical problems are identified, and the future perspective of functional separators for the safety of lithium metal batteries is also discussed.

Cranio-cervical and traumatic brain injury patterns-do they differ between electric bicycle, bicycle, and motorcycle-induced accidents?

With the growing technical options of power transmission and energy-saving options in electric drives, the number of E-bike-related accidents especially in an elderly population has increased. The aim of the current study was to compare if the increased velocity in comparison to conventional bikes translates into different injury patterns in the cranio-cervical and head region. A retrospective cohort study was performed in patients admitted to our level one trauma center between 2009 and 2019 after being involved in an accident with either an E-bike, bicycle, or motorcycle and suffered cranio-cervical or traumatic brain injury. cranio-cervical/intracranial injury pattern. Data interpretation was conducted in an interdisciplinary approach. From 3292 patients treated in this period, we included 1068 patients. E-bikers were significantly older than bicyclists (or motorcyclists) and lay between the other two groups in terms of helmet use. Overall injury patterns of E-bikers resembled those found in motorcyclists rather than in bicyclists. E-bikers had a higher incidence of different cerebral bleedings, especially if no helmet was worn. Helmet protection of E-bikers resulted in a comparable frequency of intracranial bleeding to the helmeted bicyclists. The overall pattern of head and cervical injuries in E-bikers resembles more to that of motorcyclists than that of bicyclists. As they are used by a more senior population, multiple risk factors apply in terms of complications and secondary intracranial bleeding. Our study suggests that preventive measures should be reinforced, i.e., use of helmets to prevent from intracranial injury.

Cycling speed variation: a multilevel model of characteristics of cyclists, trips and route tracking points

AbstractSmooth cycling can improve the competitiveness of bicycles. Understanding cycling speed variation during a trip reveals the infrastructure or situations which promote or prevent smooth cycling. However, research on this topic is still limited. This study analyses speed variation based on data collected in the Netherlands, using GPS-based devices, continuously recording geographical positions and thus the variation in speeds during trips. Linking GPS data to spatial data sources adds features that vary during the trip. Multilevel mixed-effects models were estimated to test the influence of factors at cyclist, trip and tracking point levels. Results show that individuals who prefer a high speed have a higher average personal speed. Longer trips and trips made by conventional electric bicycles and sport bicycles have a higher average trip speed. Tracking point level variables explain intra-trip cycling speed variations. Light-medium precipitation and tailwind increase cycling speed, while both uphill and downhill cycling is relatively slow. Cycling in natural and industrial areas is relatively fast. Intersections, turns and their adjacent roads decrease cycling speed. The higher the speed, the stronger the influence of infrastructure on speed. Separate bicycle infrastructure, such as bike tracks, streets and lanes, increase speed. These findings are useful in the areas of cycling safety, mode choice models and bicycle accessibility analysis. Furthermore, these findings provide additional evidence for smooth cycling infrastructure construction.

PANORAMIC REVIEW OF MANAGEMENT, CONSERVATIVE TREATMENT AND SHOULDER REDUCTION TECHNIQUES

Introduction: The glenohumeral joint combines a wide range of motion and insufficient bony stabilization, making it susceptible to instability and dislocations. Glenohumeral dislocations are commonly attributed to contact sports, as well as bicycle accidents, falls and high impact trauma. Objective: to detail current information related to the incidence, clinical evaluation, imaging assessment, management, conservative treatment and shoulder reduction techniques of shoulder dislocations. Methodology: a total of 30 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 16 bibliographies were used because the other articles were not relevant for this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: shoulder dislocation, glenohumeral dislocation, shoulder reduction maneuvers, shoulder reduction techniques. Results: The shoulder joint is frequently correlated to dislocations, showing up to 45% of all dislocations. Inferior as well as superior dislocations are rare. Chronic glenohumeral dislocations are infrequent injuries accounting for less than 2%. Anterior glenohumeral dislocations account for about 90% of shoulder dislocations. Approximately 50% to 79% of posterior glenohumeral dislocations are overlooked. Conclusions: As the epidemiology indicates, there is a high incidence of shoulder dislocations, so it is important to recognize the importance of adequate clinical assessment, diagnosis and knowledge of reduction maneuvers for the management of glenohumeral dislocations. There are several types of maneuvers that can be used for reduction of a dislocated shoulder, these maneuvers can be chosen according to the case of the affected individual, in addition to the preference and experience of the person who is going to perform the reduction maneuver. Imaging tests play an important role both at diagnosis and post-reduction to confirm reduction. KEY WORDS: shoulder, dislocation, techniques, reduction, conservative.

Do Risk-Taking Cyclists Have Different Sociodemographic Characteristics? An Observational Study at Intersections in a French City

The increase in cycling accidents can hinder the increased use of this transportation mode. To identify the sociodemographic factors explaining risky cyclists’ behaviors is therefore important. The relationships between some sociodemographic variables (gender, age, parenthood, use of a shared versus a personal bike) and some risky behaviors (helmet use, red-light running, crossing an intersection with a very short time before the next passing vehicle) remain inconsistent or under-investigated in the literature. These relationships were therefore investigated in a French population. Cyclists ( N = 2,788) were observed at two traffic signal intersections in the city center of Lille, France. Two cameras per site were used to score each cyclist’s variables (with a minimum of intercoder reliability = 80%). Men (versus women) and young (versus older) cyclists are less likely to wear a helmet and more likely to run red lights. Cyclists with (versus without) a child seat were more likely to wear a helmet, suggesting that parenthood influences risk perception. Shared (versus personal) bike users were found to be significantly less likely to wear a helmet and more likely to run red lights. This highlights the importance of further investigating whether shared bike users are more likely to take different types of risk on the road. Various factors (psychosocial, enforcement, road design) are discussed to explain these findings and prevent risks. The importance of adapting road safety interventions to the sociodemographic characteristics of cyclists is also discussed.

Epidemiological Study of Traumatic Brain and Spinal Injuries in a Pediatric Population: A One-Year Analysis of Prevalence, Causes and Trends.

Background Traumatic brain injury (TBI) and spinal cord injury (SCI) are leading causes of morbidity and mortality in pediatric patients. However, the epidemiology of pediatric brain and spine injuries in Bulgaria is poorly documented. This study aims to analyze and identify the prevalence, causes, and trends of traumatic brain and spinal cord injuries in pediatric patients during the period of 1st June 2022 to 30th June 2023. Methods A retrospective study was conducted on the medical records of patients under 18 years of age who visited the emergency department of University Multiprofile Hospital for Active Treatment (UMHAT) Burgas, Bulgaria between 1st June 2022 and 30th June 2023. The incidence and etiology were stratified by age, gender, and anamnesis.Data processing and analysis were performed with the statistical package IBM SPSS v. 26.0 (IBM Corp., Armonk, NY, USA), and graphical analysis with MS Office Excel 2016 (Microsoft, Redmond, WA, USA). Means ± standard deviation and 95% confidence interval were calculated. All p-values less than 0.05 were considered indicative of statistical significance. Results Data for patients aged <18 years, admitted to the emergency department (ED) of UMHAT Burgas, Bulgaria from 1st June 2022 to 30th June 2023 were analyzed (n=38504). Of these patients, 32% were children (n=13857). One hundred thirty-four (0.3%) of the pediatric patients were hospitalized in the neurosurgical ward, and 4653 (10.7%) were hospitalized in other wards. Of the analyzed patients, 89 are boys (66.4%), 45 are girls (33.6%) (male-female ratio 2:1) and the mean age of the patients with a head trauma was 8.07 years old. The average number of patients by diagnosis is 13.4±35.37. The largest percent are patients with brain concussion (85.07%, n=114), followed by contusion of the nerve roots in the lumbar region or late contusion wound of the head (with 2.99% each, n=4); hydrocephalus or skull fracture (with 2.24% each, n=3); contusion of the nerve roots in the thoracic region (1.49%, n=2); and fracture at Th9 vertebrae, fracture at C2 vertebrae, brain trauma or brain tumor (with 0.75% each, n=1). The average number of patients by anamnesis is 13.2±17.99.The largest percent are patients who fall from their own height (44.78%, n=60); followed by falls from height (20.90%, n=28); car accident (7.46%, n=10); injured by fight, fall from a bicycle or incident during a football game (with 5.97% each, n=8); fall from electric scooter (4.48%, n=6); hit in the closet (2.99%, n=4); and finally from bike accident or hit by a rock (with 0.75% each, n=1). From 134 hospitalized patients in neurosurgery, 114 (85.07%) did not require surgical treatment and were treated with conservative treatment and 20 (14.93%) were treated surgically. Conclusion In conclusion, this study highlights a significant burden of pediatric traumatic brain and spinal injuries in Bulgaria. The majority of cases were managed conservatively, emphasizing the need for preventive measures.

What Is the Relationship Between Maxillofacial Injury Location and Associated Injuries?

BackgroundPatients sustaining maxillofacial fractures are at risk for associated injuries to other body regions. The incidence of associated injuries (AIs) is reported to be from 20 to 35%. AIs may be life-threating and play a key role in considering first-line management at the emergency department, as well as planning the definitive treatment of maxillofacial fractures. PurposeThe study aimed to determine the frequency and risk factors for AIs in patients with maxillofacial fractures. Study design, settings, sampleThe investigators designed and implemented a retrospective cohort study of patients with facial fractures treated at Central Hospital (Lahti, Finland) from January 1, 2009 through December 31, 2019. All adult patients with verified maxillofacial fractures were included. Patients under 18 years were excluded from the study. Predictor variableThe predictor variable was the location of the maxillofacial fractures grouped into three categories, mandible alone, midface alone, both midface and mandible. Main outcome variableThe primary outcome variable was associated body region injuries coded as present or absent. The secondary outcome variable was the location of the AI categorized as skull, neck, thorax, pelvis, or extremity injuries. CovariatesOther study variables included demographic data (age, sex, alcohol use), Glasgow Coma Scale (GCS), and etiology (fall, traffic- and bicycle accident, assault, pedestrian hit by motor vehicle, work-related, or sports/free-time injuries). AnalysesContinuous variables were analyzed for normal distribution using the Shapiro-Wilks test and compared with categorical variables using the Mann-Whitney test. The univariate analyses of categorical variables were analyzed by the x2 test (P ≤ 0.05 was considered statistically significant). ResultsDuring the study period, 443 adult (≥18) patients had maxillofacial fractures. AIs were present in 88 subjects (20%). The mean age was 47.6 years (range 18-91); 52 years with AIs (range 19-91), and 47 years (range 18-92) without AIs (p = 0.03). Subjects with midface and mandible + midface fractures had greater risk to AIs compared to mandibular fractures. (RR 2.0, p=0.002, RR 2.8, p=0.009). Conclusions and RelevancyEvery fifth maxillofacial trauma patient had associated injury. Trauma patients should be evaluated in institutions with trauma protocols and imaging modalities before determining and executing the treatment plan for maxillofacial fractures.

Management of pancreatic and duodenal trauma in childhood: a university hospital experience over a 10-year period

PurposeDuodenal/pancreatic injuries occur in less than 10% of intra-abdominal injuries in pediatric blunt trauma. Isolated duodenal/pancreatic injuries occur in two-thirds of cases, while combined injuries occur in the remaining. This study aimed to investigate pediatric patients with pancreatic and duodenal trauma.MethodsData from 31 patients admitted to Atatürk University, Medical Faculty, Department of Pediatric Surgery for pancreatic/duodenal trauma between 2010 and 2019 were retrospectively analyzed. Age/gender, province of origin, duration before hospital admission, trauma type, injured organs, injury severity, diagnostic and therapeutic modalities, complications, hospitalization duration, blood transfusion requirement, and mortality rate were recorded.ResultsTwenty-four patients were male, and 7 were female. The mean age was 9 years. The leading cause was bicycle accidents, with 12 cases, followed by traffic accidents/bumps, with 7 cases each. Comorbid organ injuries accompanied 18 cases. Duodenal trauma was most commonly accompanied by liver injuries (4/8), whereas pancreatic injury by pulmonary injuries (7/23). Serum amylase at initial hospital presentation was elevated in 83.9% of the patients. Thirty patients underwent abdominal CT, and FAST was performed in 20. While 54.8% of the patients were conservatively managed, 45.2% underwent surgery.ConclusionBecause of the anatomical proximity of the pancreas and the duodenum, both organs should be considered being co-affected by a localized trauma. Radiologic confirmation of perforation in duodenal trauma and an intra-abdominal pancreatic pseudocyst in pancreatic trauma are the most critical surgical indications of pancreaticoduodenal trauma. Conservative management’s success is increased in the absence of duodenal perforation and cases of non-symptomatic pancreatic pseudocyst.

IDENTIFYING THE ROLE OF ELECTROLYTE ADDITIVES FOR LITHIUM PLATING ON GRAPHITE ELECTRODE BY OPERANDO X‐RAY TOMOGRAPHY

The plating of lithium on the graphite electrode is a major degradation mechanism in lithium‐ion batteries (LIBs) and brings safety concerns and leads to short cycle life. Understanding how and when plating occurs is crucial for the development of mitigation strategies, e.g. tuning the electrolyte composition. We present an operando X‐ray tomographic microscopy study to monitor the plating of lithium on a graphite electrode. XTM enables non‐destructive, quantitative operando characterization of lithium deposition and allows us to probe the role of the electrolyte additives vinylene carbonate and lithium bis(fluorosulfonyl)imide in the standard electrolyte LP57. The additives show a better performances in terms of delayed onset of lithium plating, important to utilise the full capacity of the graphite, since once lithium plating is initiated this rapidly becomes dominating and hinders further intercalation. For the base electrolyte a homogeneous and dense morphology of plated lithium is found, whereas a more dendritic morphology is observed in the presence of additives. During delithiation, there is a rapid stripping of some of the plated lithium followed by deintercalation. In addition, our work provides a general methodology to track the morphology of plated lithium, which is crucial for fundamental research about battery safety.

The Progress of Polymer Composites Protecting Safe Li Metal Batteries: Solid-/Quasi-Solid Electrolytes and Electrolyte Additives.

The impressive theoretical capacity and low electrode potential render Li metal anodes the most promising candidate for next-generation Li-based batteries. However, uncontrolled growth of Li dendrites and associated parasitic reactions have impeded their cycling stability and raised safety concerns regarding future commercialization. The uncontrolled growth of Li dendrites and associated parasitic reactions, however, pose challenges to the cycling stability and safety concerns for future commercialization. To tackle these challenges and enhance safety, a range of polymers have demonstrated promising potential owing to their distinctive electrochemical, physical, and mechanical properties. This review provides a comprehensive discussion on the utilization of polymers in rechargeable Li-metal batteries, encompassing solid polymer electrolytes, quasi-solid electrolytes, and electrolyte polymer additives. Furthermore, it conducts an analysis of the benefits and challenges associated with employing polymers in various applications. Lastly, this review puts forward future development directions and proposes potential strategies for integrating polymers into Li metal anodes.

A Comparison of Maxillofacial and Head Injuries Following Electric Scooter and Bicycle Accidents

The prevalence of maxillofacial and head injuries associated with electric scooters (e-scooter, ES) has risen in concordance with its popularity. The purpose of this study was to compare maxillofacial and head injury location, type, and severity related to ES and bicycle accidents and to identify factors contributing to injury severity. The authors implemented a multicenter retrospective cohort study in Seattle, Washington, and enrolled a sample of ES riders and bicyclists who sustained maxillofacial injuries between September 2020 and September 2022. The exclusion criteria included nonmotorized scooters, motorized bicycles, injuries with other operators, or vehicles, and pre-evaluation deaths. The predictor variable was vehicle type, bicycle or ES. The outcome variables included maxillofacial injury location, distinguished by horizontal facial thirds and injury type, defined as hard or soft tissue. Associated head injury types were also reported as hard (calvaria) or soft (scalp) tissue injuries. The severity of these injuries was quantified using both the injury severity score and the face and head abbreviated injury scale. Demographic, injury, and treatment-related variables were collected. Bivariate, multivariate, and regression statistics were computed. Statistical significance was P<.05. The final sample was composed of 205 total subjects, of which 52 (25.4%) were in the ES group and 153 (74.6%) in the bicycle group. Isolated midface injuries were the most common hard tissue location in the ES (15.4%) and bicycle (29.4%) groups. The most common soft tissue injury location included the upper face and midface in the ES group (19.2%) and the midface in the bicycle group (22.9%). Both hard and soft tissue head injuries were more prevalent in the ES group (P<.0002 and P<.0001). Moreover, intracranial injuries were seen in 36.5% of ES subjects compared to 9.8% bicycle subjects (P<.0001). Between the two groups there was no difference in maxillofacial injury severity, but head injuries were more severe in the ES group (P<.0002). Using regression analysis, drug use was found to have a significant impact on the mean injury severity score (P<.002) and helmet use did not have significant impact on face or head injury severity. Maxillofacial injury location, type, and severity are comparable among ES and bicycles. However, ES riders are at greater risk of severe head injuries compared to bicycles, and riding while intoxicated has the greatest effect on injury severity.

Naturalistic study of vehicle-bicycle lateral passing distance on high-speed rural two-lane roadways with paved shoulders

In the United States, 91.4 cm (3.0 ft) has been considered a safe lateral distance when passing bicyclists; however, this threshold may be more suitable to urban environments where most bicycle safety research has originated—limited research is available on rural roadways. In this study, a road bicycle was instrumented to collect naturalistic data and analyze vehicle-bicycle lateral passing distances (LPD) on high-speed rural two-lane roadways with paved shoulders. The bicycle was ridden in the center of the shoulder. Overall, 2,119 observations of vehicles passing the instrumented bicycle were obtained from a study segment. The impacts of different variables on distributions of vehicle-bicycle LPD measurements were analyzed. Passing vehicles with opposing traffic passed the bicyclist significantly closer than passing vehicles without opposing traffic. More predominant with opposing traffic, heavy vehicles passed the bicyclist closer than passenger vehicles. Similarly, following vehicles passed the bicyclist closer than leading vehicles. The study segment was repaved during the data collection period, so data before and after the roadway improvement was available. Vehicles with old pavement/marking passed the bicyclist closer than vehicles with new pavement/marking conditions. Distribution of LPD measurements was skewed to the left towards smaller values and had a long tail to the right towards larger values. Through maximum likelihood estimation, the Log-normal distribution was found to best fit the data distribution. Using empirical and theoretical density distributions, LPD was formally specified as a function of opposing traffic with a theoretical mixture distribution and generalized to estimate the probability of vehicles passing bicyclists below a certain threshold.

Integrating visual factors in crash rate analysis at Intersections: An AutoML and SHAP approach towards cycling safety

Cycling crashes constitute a significant and rising share of traffic accidents. Consequently, exploring factors affecting cycling safety has become a priority for both governmental bodies and scholars. However, most existing studies have neglected the vision factors capable of quantitatively describing the city-level cycling environment. Moreover, they have relied on limited models that lack interpretability and fail to capture the spatial variations in the contribution of factors. To address these gaps, this research proposed a framework that used origin–destination-based cycling flow and vision factors generated from Google Street View images to identify the leading factors. It also employed the comparative Automatic Machine Learning and interpretable SHAP value-based geospatial analysis to explain each factor’s contribution to the cycling crash risk, with a particular focus on the spatial variations in the influence of vision factors. The effectiveness of this framework was validated by a case study in Manhattan, which examined the leading risk factors of cycling crash rates at intersections. The results showed that the LightGBM model, with selected subsets of factors, outperformed other models. Through SHAP explanations of global feature importance, the study identified the proportion of road barriers, the proportion of open sky, and the number of visible trucks as the leading visual risk factors. Additionally, using SHAP-based geospatial analysis, the study revealed the local variations in the effects of these three factors and identified eight areas with higher cycling crash rates. Based on these findings, the study provided practical measures for a safer cycling environment in Manhattan.

Unraveling the relation between cycling accidents and built environment typologies: Capturing spatial heterogeneity through a latent class discrete outcome model

Today, cities seek to transition to more sustainable transportation modes. Cycling is critical in this shift, promoting a more beneficial lifestyle for most. However, cyclists are exposed to many hazardous circumstances or environments, resulting in accidents, injuries, and even death. Transport authorities must understand why accidents occur, to reduce the risk of those who cycle.This study applies a new modeling framework to analyze cycling accident severities. We employ a latent class discrete outcome model, where classes are derived from a Gaussian–Bernoulli mixture, applied to data from Berlin, and augmented with volunteered geographic information. We jointly estimate model components, combining machine learning and econometric approaches, allowing for more intricate and flexible representations while maintaining interpretability.Results show the potential of our approach. Risk factors are indexed depending on where accidents occurred and their contribution. We can discover complex relations between specific built environments and accident characteristics and uncover differences in the impact of certain accident factors on one environment typology but not others. Using multiple data sources also proves helpful as an additional layer of knowledge, providing unique value to understand and model cycling accidents. Another critical aspect of our approach is the potential for simulation, where locations can be examined through simulated accident features to understand the inherent risk of various locations.These findings highlight the ability to capture heterogeneity in accidents and their relation to the built environment. Capturing such relations allows for more direct countermeasures to risky situations or policies to be designed, simulated, and targeted.

Battling a Recurrent Thigh Lymphocele After a Bike Accident

Battling a Recurrent Thigh Lymphocele After a Bike Accident

Two-in-one strategy for optimizing chemical and structural properties of carbon felt electrodes for vanadium redox flow batteries

ABSTRACT Vanadium redox flow batteries (VRFBs) have received significant attention for use in large-scale energy storage systems (ESSs) because of their long cycle life, flexible capacity, power design, and safety. However, the poor electrochemical activity of the conventionally used carbon felt electrode results in low energy efficiency of the VRFBs and consequently impedes their commercialization. In this study, a carbon felt (CF) electrode with numerous nanopores and robust oxygen-containing functional groups at its edge sites is designed to improve the electrochemical activity of a carbon felt electrode. To achieve this, Ni metal nanoparticles were initially precipitated on the surface of the CF electrode, followed by etching of the precipitated Ni nanoparticles on the CF electrode using sulfuric acid. The resulting CF electrode had a specific surface area eight times larger than that of the pristine CF electrode. In addition, the oxygen-containing functional groups anchored at the graphite edge sites of the nanopores can act as robust electrocatalysts for VO2+/VO2 + and V2+/V3+ redox reactions. Consequently, the VRFB cell with the resulting carbon felt electrode can deliver a high energy efficiency of 86.2% at the current density of 60 mA cm−2, which is 20% higher than that of the VRFB cell with the conventionally heat-treated CF electrode. Furthermore, the VRFB cell with the resultant carbon felt electrodes showed stable cycling performance with no considerable energy efficiency loss over 200 charge-discharge cycles. In addition, even at a high current density of 160 mA cm−2 , the developed carbon felt electrode can achieve an energy efficiency of 70.1%.