Analyzing traffic conflicts and the behavior of motorcyclists at unsignalized three-legged and four-legged intersections in Cartagena, Colombia.

INTRODUCTION: The global motorcycle market has grown significantly, with over 770 million vehicles estimated to be in use worldwide. Motorcycle-related road traffic deaths in low and middle-income countries (LMICs) like Colombia are concerning, comprising 30% of all reported fatalities. Cartagena has an average of 70 motorcycle-related deaths annually between 2019 and 2022, making it a high-risk area for motorcyclists. OBJECTIVE: The study aimed to identify factors associated with motorcyclist safety at unsignalized three-legged and four-legged intersections in Cartagena by observing the behavior of the motorcyclists and the analysis of the potential traffic conflicts. The observational analysis focused on the access of motorcyclists from a secondary road to a main road since it is the behavior offered by the most significant road interaction and the potential risk of traffic conflicts due to crossing. METHODS: The observational process was consolidated at ten three-legged intersections and seven four-legged intersections. Thirty-six hours of videos were collected considering different time slots and weekdays randomly distributed during September 2019 and March 2020. The selection of the intersections included different vehicular flows and road safety conditions. The variables considered in the study were: interaction with other road users, motorcyclist behavior, vehicle handling, potential distractors, and safety elements. The study used the Swedish Traffic Conflict Technique to analyze conflict analysis, incorporating the Post Encroachment Time (PET) measurement. The analysis was developed with descriptive and inferential statistical techniques. The collected variables were analyzed individually (frequency analysis), and contrasts were conducted with the PET values. The study evaluated associations between motorcycles and other motorized road actors at intersections about behaviors and crossroads. RESULTS: In the Records, 10,281 motorcycle accesses at three and four-Legged Intersections were interactions with other road users, where 2417 and 1903 resulted in potential traffic conflicts, respectively. Average potential conflicts per hour were 115 and 127 at three and four-legged intersections. At the two intersections, the average PET values in motorcycles were between 2.09 and 2.10 s, while in the other motorized road users, it averaged around 2.67 to 2.71 s. In the road conditions, it was identified that intersections with a traffic flow of<10,000 vehicles/day and poor visibility to the left of the intersection lead to more unsafe conditions for motorcyclists. Motorcycle taxi drivers were the user group most frequently involved in traffic conflicts. Actions on the part of motorcyclists, such as risky behaviors, not using helmets, not using turn signals, and not waiting patiently for access, showed a relationship with the potential for traffic conflicts. Finally, turns to the left, particularly the indirect turn to the left on the opposite road, showed a greater risk of traffic conflicts. CONCLUSIONS: The study found that motorcycles exhibit more severe traffic conflicts than motorized vehicles at intersections. Infrastructure conditions significantly impact the risk of intersection conflicts. Individual behaviors such as not stopping at intersections and driving recklessly increased the risk of traffic conflicts. The study recommends improving infrastructure such as visibility and signaling and implementing separators to reduce travel speed and traffic conflicts for motorcycles.

Understanding motorcyclist-related accidents in Colombia.

In 2016, Colombia's position regarding motorcyclist fatalities per 100,000 inhabitants was tenth worldwide and second in South America. In the seven years from 2012-2018, the proportion of deceased and injured motorcyclists among all road users was 50%. To analyse the significant aspects of the accident rate of motorcyclists in Colombia from 2016 to 2018 and estimate cost social value of motorcycle-related deaths. The global numbers of fatalities and injuries were compared to the Colombian context. Descriptive and inferential statistics were conducted to explore the association of fatal trauma and motorcycle accidents. P values and odds ratios were calculated. Bogotá, Cali, and Medellín were the cities with the most accidents. The month, day, time, age of the victims, and climatic conditions had a statistically significant association with the fatal trauma. Most victims were between the ages of 20-29 years. Motorcycles were involved in more than 60% of accidents. The social cost of a life lost in a motorcycle accident was estimated at $2,418 million Colombian pesos (725,400 USD) per year. The establishment of countermeasures for the road safety of vulnerable users should focus on associated causal factors in order to develop strategies to effectively reduce the number of accidents.

Seating configuration and position preferences in fully automated vehicles.

Objective: This study aimed to understand seating configuration and position preferences in a fully automated vehicle (FAV) across 7 hypothetical traveling scenarios.Methods: Participants completed an online survey in which they were asked to imagine traveling in an FAV across 7 hypothetical traveling scenarios and asked to select 1 of 5 seating configurations and 1 of 4 seating positions for themselves and for any additional occupants. Furthermore, participants were asked to indicate any activities that they and any additional occupants would engage in and whether they would be willing to wear a different seat belt in an FAV while seated in a non-forward-facing mode or while reclined.Results: Five hundred and fifty-two participants (male = 50.5%; mean = 36.6 years, SD = 14.0 years) completed the online survey. Most participants resided in Australia (40.9%), Spain (16.5%), Sweden (15.6%), or Lebanon (19.4%). Most participants drove on a daily basis (60.0%), had driven between 5,000 and 15,000 km in the previous year (33.2%), and reported that they always or almost always wear a seat belt while traveling in a motor vehicle (98.2%). Across all scenarios, participants were most likely to prefer a conventional seating configuration (i.e., all seats facing forward; between 40.0 and 76.3%). In terms of seating position preferences, participants preferred seating position A (i.e., the conventional driver's seat; between 54.6 and 68.3%), regardless of with whom they were traveling. The most common activity while traveling alone was reading (25.0%). However, when traveling with other occupants, talking was the most common activity (41.0-63.0%), even with someone they did not know (31.0%). Most participants predicted that they would always or almost always wear a seat belt when traveling in an FAV (95.9%). Most participants also reported that they would be very willing or willing to wear a different seat belt configuration in an FAV while seated in a non-forward-facing mode or while reclined (73.8 and 80.7%, respectively).Conclusions: This study has provided valuable insight regarding seating configuration and position preferences in an FAV, as well as predicted activities and restraint use. Future research will use this information to simulate likely injury outcomes of these preferences in the event of a motor vehicle crash and provide a basis for the design of occupant protection systems for FAVs.

Video-based assessment of pedestrian behavior: development and testing of methods / Estudio de comportamiento peatonal basado en video: desarrollo y prueba de los métodos

ABSTRACT Objective The aim of this paper is to develop a computer algorithm that analyzes pedestrian behavior at an urban site in Bogota, Colombia, considering that the assessment of pedestrian behavior is a road safety priority. Methods Pedestrians were video-taped as they crossed a selected road. An algorithm was developed in order to record, from these videos, pedestrian and vehicle positions and speeds. This information made possible the identification of hazardous behaviors, which were compared through visual assessments. Results 429 pedestrians crossed the selected road at an average distance of 4.5 meters from vehicles that moved at an average speed of 21 km/h. With a maximum difference of 19 % with respect to visual assessments, the algorithm estimated that 58.5 % pedestrians crossed through non-designated locations; 62.2 % crossed near moving vehicles, and that 41.2 % ran while they were crossing the road. Conclusions Video-based analysis can be used to assess pedestrians' behavior. Future research work should focus on improving both the accuracy and the number of safety parameters of the algorithm.(AU)

RESUMEN Objetivo La medición del comportamiento de peatones es una prioridad de la seguridad vial. Por lo anterior, se desarrolló un algoritmo para analizar el comportamiento de los peatones en una zona urbana de Bogotá, Colombia. Métodos Los peatones fueron filmados mientras cruzaban la calle. Mediante el algoritmo se midieron las posiciones y velocidades de peatones y vehículos en los videos. Se identificaron los comportamientos riesgosos y se compararon visualmente. Resultados 429 peatones cruzaron la vía a una distancia promedio de 4.5 metros de los vehículos (velocidad promedio 21 km/h). El algoritmo estimó, con una diferencia máxima de 19 % con respecto a lo observado, que 58.5 % de los peatones cruzaron por zonas incorrectas, 62.2 % cruzaron cerca de vehículos en movimiento y 41.2 % corrieron al cruzar. Conclusiones El análisis basado en video puede utilizarse para medir el comportamiento de los peatones. Los trabajos sobre el tema que se realicen en el futuro deben enfocarse en mejorar la precisión y los parámetros de seguridad del algoritmo.(AU)

Video-based assessment of pedestrian behavior: Development and testing of methods.

OBJECTIVE: The aim of this paper is to develop a computer algorithm that analyzes pedestrian behavior at an urban site in Bogota, Colombia, considering that the assessment of pedestrian behavior is a road safety priority. METHODS: Pedestrians were video-taped as they crossed a selected road. An algorithm was developed in order to record, from these videos, pedestrian and vehicle positions and speeds. This information made possible the identification of hazardous behaviors, which were compared through visual assessments. RESULTS: 429 pedestrians crossed the selected road at an average distance of 4.5 meters from vehicles that moved at an average speed of 21 km/h. With a maximum difference of 19 % with respect to visual assessments, the algorithm estimated that 58.5 % pedestrians crossed through non-designated locations; 62.2 % crossed near moving vehicles, and that 41.2 % ran while they were crossing the road. CONCLUSIONS: Video-based analysis can be used to assess pedestrians' behavior. Future research work should focus on improving both the accuracy and the number of safety parameters of the algorithm.

Relación entre el dolor lumbar y los movimientos realizados en postura sedente prolongada: Revisión de la literatura / The relationship between low back pain and movements in prolonged sitting posture: Literature review

La evidencia científica muestra que existe asociación entre dolor lumbar y postura sedente prolongada y que una de las poblaciones más propensa a esta enfermedad es la de conductores, con una alta prevalencia. De igual manera, los movimientos posturales en la silla son la respuesta natural del cuerpo debida a la incomodidad percibida por el dolor lumbar, pero esta difiere en función de la historia previa. Con base en esto se realizó una revisión de los estudios relacionados con el dolor lumbar y el movimiento en postura sedente prolongada, incluyendo la población de conductores, con el fin de comprender esta relación. Se recuperaron 6226 artículos, de los cuales 16 fueron publicados entre 1970 y 2010; estos proporcionaron la información necesaria para contestar la pregunta de revisión. Se pudo constatar que ninguno de los estudios fueron realizados en actividades de conducir y la mayoría involucró sujetos voluntarios sin considerar si la población era trabajadora. El movimiento con dolor lumbar en postura sedente prolongada solo se pudo explicar desde el rango de movimiento lumbar, debido a que solo se encontró un artículo con estas características. También se encontró que los sintomáticos se mueven más, pero que el dolor lumbar no disminuye en función del tiempo, es decir que conocemos muy poco acerca de la paradoja movimiento y dolor en postura sedente prolongada.

Scientific evidence shows an association between low back pain and prolonged sitting posture, also one of the most sensitive populations to this disorder are the drivers with a high prevalence. Postural movements in the chair are body's natural response to perceived discomfort caused by back pain but this is different depending on each individual's background of back pain. Based on this, we perform a review of studies related to low back pain and movement in prolonged sitting posture, including the driver population, in order to understand this relationship. We retrieved 6226 articles, of which 16 matched the established criteria and provided the information necessary to answer the review question. We found that none of the studies considered were conducted in driving activities and most of them were done with volunteer subjects regardless if they were workers or not. The movement with low back pain in prolonged sitting posture could only be explained from the range of lumbar motion because only one article matched these characteristics, finding that symptomatic people move more but low back pain does not decrease as a function of time, proving that we know very little about the paradoxical between movement and pain in prolonged sitting posture.