Incorporating real-time traffic and weather data to explore road accident likelihood and severity in urban arterials

IntroductionThe effective treatment of road accidents and thus the enhancement of road safety is a major concern to societies due to the losses in human lives and the economic and social costs. The investigation of road accident likelihood and severity by utilizing real-time traffic and weather data has recently received significant attention by researchers. However, collected data mainly stem from freeways and expressways. Consequently, the aim of the present paper is to add to the current knowledge by investigating accident likelihood and severity by exploiting real-time traffic and weather data collected from urban arterials in Athens, Greece.MethodRandom Forests (RF) are firstly applied for preliminary analysis purposes. More specifically, it is aimed to rank candidate variables according to their relevant importance and provide a first insight on the potential significant variables. Then, Bayesian logistic regression as well finite mixture and mixed effects logit models are applied to further explore factors associated with accident likelihood and severity respectively.ResultsRegarding accident likelihood, the Bayesian logistic regression showed that variations in traffic significantly influence accident occurrence. On the other hand, accident severity analysis revealed a generally mixed influence of traffic variations on accident severity, although international literature states that traffic variations increase severity. Lastly, weather parameters did not find to have a direct influence on accident likelihood or severity.ConclusionsThe study added to the current knowledge by incorporating real-time traffic and weather data from urban arterials to investigate accident occurrence and accident severity mechanisms.Practical applicationThe identification of risk factors can lead to the development of effective traffic management strategies to reduce accident occurrence and severity of injuries in urban arterials.     

Exploring the factors affecting motorway accident severity in England using the generalised ordered logistic regression model

ProblemThe severity of motorway accidents that occurred on the hard shoulder (HS) is higher than for the main carriageway (MC). This paper compares and contrasts the most important factors affecting the severity of HS and MC accidents on motorways in England.MethodUsing police reported accident data, the accidents that occurred on motorways in England are grouped into two categories (i.e., HS and MC) according to the location. A generalized ordered logistic regression model is then applied to identify the factors affecting the severity of HS and MC accidents on motorways. The factors examined include accident and vehicle characteristics, traffic and environment conditions, as well as other behavioral factors.ResultsResults suggest that the factors positively affecting the severity include: number of vehicles involved in the accident, peak-hour traffic time, and low visibility. Differences between HS and MC accidents are identified, with the most important being the involvement of heavy goods vehicles (HGVs) and driver fatigue, which are found to be more crucial in increasing the severity of HS accidents.Practical applicationsMeasures to increase awareness of HGV drivers regarding the risk of fatigue when driving on motorways, and especially the nearside lane, should be taken by the stakeholders.     

Factors affecting the severity of injuries among young motorcyclists--a Swedish nationwide cohort study

OBJECTIVES: To determine factors affecting the severity of motorcycle injuries, considering variables related to the individual, the environment, the vehicle, and the crash. METHODS: This is a register-based retrospective cohort study. All individuals born in 1970-1972 (n = 334,070) were extracted from the Swedish Population and Housing Census of 1985 and followed up from 1988 to 2000, when aged 16-30. All subjects whose records indicated an injury as a motorcycle driver in the Swedish National Road Administration Accident Database were selected, and constituted the study population (n = 1,748). Factors related to the individual, the environment, the vehicle, and the crash were considered as exposure measures, whereas the outcome measure was the level of injury severity, based on assessments made on-site by police officers, in two categories: fatal/severe and minor. Associations between individual, environmental, vehicle and crash factors and injury severity were measured, using Chi-square, and through univariate and multivariate stepwise logistic regression. RESULTS: Factors such as alcohol consumption, traffic environment, speed limit, and type of crash were significantly associated (p < 0.0001) with injury severity. More specifically, a positive suspicion of alcohol consumption, driving in a rural area, and a posted speed limit over 50 km/hour were all factors positively associated (OR > 1.0) with the likelihood of being severely injured. On modeling all the variables together through stepwise logistic regression, positive suspicion of alcohol emerged as the strongest determinant (adjusted OR = 2.7) of a severe outcome. CONCLUSIONS. Motorcycle crashes still place a heavy burden on young drivers. Increased efforts are needed to prevent alcohol-related crashes-through law enforcement and a multiplicity of policies at local and national levels.     

孔内外微差爆破技术在路堑开挖中的应用

介绍了孔内外微差爆破技术在路堑开挖中的应用。实践证明 ,这种爆破技术可控制爆破振动和飞石 ,提高爆破效率     

Road traffic accident severity analysis: A census-based study in China

Background: In China, despite the decrease in average road traffic fatalities per capita, the fatality rate and injury rate have been increasing until 2015. Purpose: This study aims to analyze the road traffic accident severity in China from a macro viewpoint and various aspects and illuminate several key causal factors. From these analyses, we propose possible countermeasures to reduce accident severity. Method: The severity of traffic accidents is measured by human damage (HD) and case fatality rate (CFR). Different categorizations of national road traffic census data are analyzed to evaluate the severity of different types of accidents and further to demonstrate the key factors that contribute to the increase in accident severity. Regional data from selected major municipalities and provinces are also compared with national traffic census data to verify data consistency. Results: From 2000 to 2016, the overall CFR and HD of road accidents in China have increased by 19.0% and 63.7%, respectively. In 2016, CFR of freight vehicles is 33.5% higher than average; late-night accidents are more fatal than those that occur at other periods. The speeding issue is severely becoming worse. In 2000, its CFR is only 5.3% higher than average, while in 2016, the number is 42.0%. Conclusion and practical implementation: A growing trend of accident severity was found to be contrasting to the decline of road traffic accidents. From the analysis of casual factors, it was confirmed that the release way of the impact energy and the protection worn by the victims are key variables contributing to the severity of road traffic accidents.     

基于数值模拟的城市中心区风环境研究

利用CFD软件对长沙市中心区典型区域的风环境进行了三维数值模拟研究。结果表明,城市建筑群布局不当会造成多方面不利影响:如建筑群内局部地区气流不畅,污染物难以扩散,影响市民身体健康;街道峡谷风使得行人行动不便,冬季热舒适感差;复杂的风环境可能造成建筑构件的损坏乃至脱落,对地面行人的安全造成威胁;建筑围护结构渗透风增加造成建筑能耗的增加。在城市规划和建设中,中心区风环境状况要引起足够的重视,在建设之前要进行风环境模拟与评估。     

An urban pipeline accident model based on system engineering and game theory

Urban pipeline accidents are caused by complex social-technical factors, in which urban communities and pipeline systems are involved. Such accidents can thus be investigated from the viewpoint of system engineering. System-Theoretic Accident Model and Processes (STAMP) is a systemic method for safety assessment, which has been adopted in many domains. This approach can provide deep insights of accident causes by considering direct and indirect factors. Meanwhile, competition and cooperation between stakeholders in accidents are observed. Therefore, these parties can also be analyzed with the game theory. That is, stakeholders in STAMP can be regarded as players in game. The aim of this paper is to provide a new insight to analyze urban pipeline accidents by considering both STAMP and game theory. In this paper, we proposed an accident model for urban pipelines, with a case study of China-Qingdao pipeline accident occurred in 2013. We concluded that accident reasons can be investigated in-depth and lessons can be learned from analyzing causal factors by using STAMP. Based on results generated from STAMP, we applied the game theory to analyze roles that government and companies act in the China-Qingdao urban pipeline accident. The results show that current punishment and incentive systems are incomplete, lacking of the driving force and constraining force for the stakeholders involved in the accident.     

城镇油气管道事故应急疏散决策优化

为实现油气管道事故中城镇大规模应急疏散的智慧决策,构建基于改进的自适应蚁群算法的应急疏散路径优化模型,开发基于油气管道典型事故后果分析的城镇大规模应急疏散决策优化系统平台(LSSED)。LSSED在地理信息系统平台上,针对油气管道泄漏引起的扩散、喷射火、池火、BLEVE、蒸气云爆炸等典型事故进行事故后果分析,对疏散通道当量长度和疏散时间成本函数进行定量评价,实现大规模应急疏散方案的智慧决策和避难方案的全局优化。案例分析表明,LSSED平台实现了基于地理信息系统的典型事故时变环境信息和应急疏散路径优化算法的数据传递及系统集成,实现了基于事故后果分析的城镇大规模人群疏散路径和避难方案优化,可为城镇安全规划和应急管理提供参考和借鉴。     

Side impact crashes--factors affecting incidence and severity: review of the literature

Many traffic crashes are side impact collisions resulting in significant death and injury. A review was conducted of the evidence of driver, road, and vehicle characteristics affecting either the risk of occurrence or the severity of injury in such crashes for papers published from 1996 to early 2003. For drivers, evidence was found of increased crash risk or injury severity only for age and age-related medical conditions (e.g., dementia). Traffic roundabouts and other traffic control devices--stop signs, traffic lights, and so on--had mixed results; traffic controls were better than no controls, but their effectiveness varied with circumstance. Most vehicle characteristics have had little or no effect on crash occurrence. Antilock braking systems (ABS) in the striking vehicle had been anticipated to reduce the risk of crashes, but so far have demonstrated little effect. The primary emphasis in vehicle design has been on protective devices to reduce the severity of injury. Disparity in the size of the two vehicles, especially when the struck vehicle is smaller and lighter, is almost a consistent risk factor for occupant injury. The occupants of light trucks, however, when struck by passengers cars on the opposite side, were at higher risk of injury. Wearing seat belts had a consistently protective effect; airbags did not, but there were few studies, and no field studies, of lateral airbags found. Of all the characteristics examined, vehicle design, including occupant restraints, is the most easily modified in the short term, although road design, traffic control, and the monitoring of older drivers may also prove effective in reducing side impact crashes in the longer term.     

城市供热地下管线系统危险因素辨识与事故预防对策

近年来,城市集中供热得到了迅猛的发展.随着城市供热需求的增加,供热地下管线长度迅速增长,供热地下管线事故时有发生,城市供热地下管线安全问题已成为市政地下管线安全研究的重点问题和城市发展过程中亟待解决的热点问题.本文从事故致因论的角度和事故树的方法对供热地下管线系统的危险因素和薄弱环节进行分析研究,探讨合理有效的预防对策,有效消除事故隐患,减少事故发生,对确保城市供热管网安全、稳定、正常供暖具有重要的现实意义.     

Differences in urban and rural accident characteristics and medical service utilization for traffic fatalities in less-motorized societies

Introduction

Fatalities from traffic accidents in less-motorized societies are an important global issue. We aimed to characterize the geographic differences of fatalities in such societies to facilitate the development of targeted interventions.

Method

This study linked police reports, hospital data, and vital registration data from Taiwan with special reference to accident factors in pre-hospital deaths and medical care in hospital deaths.

Results

A higher percentage of pre-hospital deaths were observed following rural as compared to urban traffic accidents. The deaths due to rural accidents can be attributed to lower use of restraints (i.e., helmets or seat belts), lower percentage of motorcyclists, and more highway accidents. A higher percentage of victims in rural accidents were transported to distant medical centers rather than to local hospitals.

Conclusion

Specific interventions, such as intelligent emergency medical systems, campaigns for helmets and seat belt usage, enforcement of helmets and seat belt use, and speed control measures should be targeted to rural areas.

Impact on industry

Cooperation between the vehicle industry and emergency medical providers in rural traffic accident rescue teams may decrease the numbers of deaths in these regions.     

An investigation of driver attitudes and behaviour in rural and urban areas in Norway

This study aimed to investigate differences in self-reported driver attitudes and behaviour in rural, peri-urban and urban areas in Norway. Age, gender and education were controlled for. An additional aim was to investigate the relations between demographics, personality variables, driver attitudes and behaviour in the complete sample and across the different geographical areas. To obtain these aims, a questionnaire was distributed by mail to a randomly selected sample from the Norwegian population registry (N = 6203). Of the distributed questionnaires the response rate was 30%. Differences in attitudes and self-reported behaviour were significant due to type of geographical area. However, the results showed that gender, age and education caused stronger differences than type of geographical area in attitudes to driving and driver behaviour. SEM-analysis failed to reject the notion that the strength of the structural relations was similar in the geographical areas. This could imply that demographic characteristics, and their compositions in rural, peri-urban and urban areas, are more important for differences in driver behaviour and attitudes than characteristics of the traffic environment.     

聚类和灰色关联度在建筑施工事故影响因素分析中的应用

建筑业是高危行业,其安全生产状况一直受到社会各界的关注.针对建筑施工过程中监管重点难以把握、施工事故多发的现状,选取1997-2006年发生的建筑施工事故数据,以多发事故高处坠落为例,通过拆分、合并、剔除筛选出10种引发高处坠落施工事故的影响因素;通过建筑施工事故因素的聚类分析,获得三类影响因素,即“人—管理—物”;应用灰色关联度分析,对各类影响因素的灰色关联度进行排序,从而找出建筑施工过程的薄弱环节,为指导施工现场安全管理人员制定有针对性监管措施和预防建筑施工事故的发生提供方法支持.     

Factors affecting vapour production in large scale evaporating liquid cascades

This paper presents a computational fluid dynamics (CFD) model of the evaporating liquid cascade produced in a large hydrocarbon storage tank overfilling incident. The model is first validated against the results of a unique series of full-scale experiments, in which liquid hexane was released from a 10 m high tower. Comparisons are presented for the temperature of both the liquid and vapour in the cascade, and the temperature of the vapour current. The validated model is then used to investigate the effects of different tank bund configurations, and the influence of an accumulating vapour layer on the vapour production process.     

Investigation of powered 2-wheeler accident involvement in urban arterials by considering real-time traffic and weather data

Objective: Understanding the various factors that affect accident risk is of particular concern to decision makers and researchers. The incorporation of real-time traffic and weather data constitutes a fruitful approach when analyzing accident risk. However, the vast majority of relevant research has no specific focus on vulnerable road users such as powered 2-wheelers (PTWs). Moreover, studies using data from urban roads and arterials are scarce. This study aims to add to the current knowledge by considering real-time traffic and weather data from 2 major urban arterials in the city of Athens, Greece, in order to estimate the effect of traffic, weather, and other characteristics on PTW accident involvement.

Methods: Because of the high number of candidate variables, a random forest model was applied to reveal the most important variables. Then, the potentially significant variables were used as input to a Bayesian logistic regression model in order to reveal the magnitude of their effect on PTW accident involvement.

Results: The results of the analysis suggest that PTWs are more likely to be involved in multivehicle accidents than in single-vehicle accidents. It was also indicated that increased traffic flow and variations in speed have a significant influence on PTW accident involvement. On the other hand, weather characteristics were found to have no effect.

Conclusions: The findings of this study can contribute to the understanding of accident mechanisms of PTWs and reduce PTW accident risk in urban arterials.     

基于有序Logit与Probit模型的交通事故严重性影响因素分析

为准确分析影响交通事故严重性的各项因素,引入有序选择模型中的Ordinal Logit模型和Ordinal Probit模型,研究驾驶员、车辆、环境、管理因素与事故严重程度之间的耦合关系,利用计量经济学理论和统计学方法对模型进行显著性检验。并选择美国北卡罗来纳州2010年至2014年385个翻车事故样本进行严重性影响因素分析,所得回归模型参数估计均符合Wald检验(p≤0.0001)和似然比检验(p≤0.0001),模型的拟合度也都符合Pearson检验(p=0.7976)、偏差检验(p=0.6006)和信息准则检验,模型预测精度指标值均大于0.7。所得两个模型中变量"安全带"(p≤0.001)、"路面状况"(p=0.0071)、"道路线形"(p=0.0077)、"路面类型"(p=0.0251)都对翻车事故的严重性具有显著影响,表明有序Logit模型和有序Probit模型均适用于分析和揭示影响交通事故严重性的各个因素。     

Risk factors associated with bus accident severity in the United States: A generalized ordered logit model

IntroductionRecent years have witnessed a growing interest in improving bus safety operations worldwide. While in the United States buses are considered relatively safe, the number of bus accidents is far from being negligible, triggering the introduction of the Motor-coach Enhanced Safety Act of 2011.MethodThe current study investigates the underlying risk factors of bus accident severity in the United States by estimating a generalized ordered logit model. Data for the analysis are retrieved from the General Estimates System (GES) database for the years 2005–2009.ResultsResults show that accident severity increases: (i) for young bus drivers under the age of 25; (ii) for drivers beyond the age of 55, and most prominently for drivers over 65 years old; (iii) for female drivers; (iv) for very high (over 65 mph) and very low (under 20 mph) speed limits; (v) at intersections; (vi) because of inattentive and risky driving.     

城市燃气管网泄漏事故分析知识图谱构建及应用研究*

为深入认识燃气管网泄漏事故的发生发展机理,提高事故分析预测的自动化、智能化、数字化水平,利用知识图谱对燃气管网泄漏事故进行研究。在事故案例分析的基础上,从人-物-环-管的角度对燃气泄漏过程以及火灾爆炸次生事故的相关实体进行归纳梳理,对实体间的逻辑关系和非逻辑关系进行辨识,并对实体的属性进行分类,进而构建出较为全面的燃气管网泄漏事故知识图谱。在此基础上,搭建BP神经网络模型,基于已知实体或属性状态,预测相关联其他实体或属性的状态。研究结果表明:燃气管网知识图谱能够有效展示燃气管网泄漏事故发展的动态过程及相关要素,结合BP神经网络能够有效预测事故的发展路径及相关状态,从而提高燃气管网泄漏事故的分析预测水平与效率。