Estimating transport fatality risk from past accident data

This paper examines the statistical properties of estimates of fatal accident rates, mean fatalities per accident, and fatality rates when these estimates are based on past accident data. The statistical properties are illustrated by two long-term transport fatal accident datasets from Great Britain, the principal one for railways and the other for roads, chosen to provide a statistical contrast. In both modes, the accident rates have fallen substantially over the long term. Two statistical estimates of current accident and fatality rates are presented for each dataset, one based only on recent data and the other based on estimates of long-term trends. The trend-based estimate is preferred for train accidents because this makes maximum use of the limited and variable data; the recent data are preferred for road accidents because this avoids unnecessary dependence on modelling the trends. For train accidents, the estimated fatality rate based on past accidents is compared with an estimate produced by the railway industry using a risk model. The statistical estimate is less than half the industry's estimate, and the paper concludes that the statistical estimate is to be preferred.     

Fatalities and injuries in the Kuwaiti construction industry

This paper presents an analysis of construction accidents in Kuwait along with accident causation and injuries that can be considered serious or fatal, so that corrective measures can be taken to decrease casualties, resulting in a safer construction industry. The paper evaluates the existing injury and cost reporting-investigation system of construction accidents in government agencies and private firms.

This research confirms that construction is the most hazardous industry in Kuwait, with accidents accounting for 48%, 38% and 34% of all disabling injuries and 62%, 38% and 42% of all fatalities in 1994, 1995 and 1996, respectively. These rates are considered high and can be compared to construction accident statistics in the U.S.A. which accounted for 14% of all work-related deaths and 9% of disabling injuries in 1993. Based on the study, falling from a height appears to be the major cause of construction injuries and fatalities in Kuwait. Poor accident records and reporting systems hide the extent of the construction safety problem in Kuwait. In addition, many people at management level are unaware of accident-related costs and the effectiveness of a safety program in reducing project costs.     

Correlates of coal mine accidents and injuries: A literature review

Coal mining is the most dangerous occupation in the United States, with injury frequency and severity rates several times the average for all industries. Although mine safety improved slightly during the early 1970's, recent trends indicate small decreases in accidents and injuries and, in some cases, increases in accident severity. Experienced miners have lower risks of fatal injuries than inexperienced miners. Workers in small mines are more likely to receive fatal injuries than those in large mines. The various engineering methods of extracting coal from its natural deposit do not produce different fatality rates. The thickness of the coal seam mined is not related to the incidence of fatalities. Although conflicting evidence appears in the literature, recent studies find younger miners with much higher disabling injury rates than older miners. Whether a collective bargaining agreement is in effect is unrelated to accident and injury occurrence at a mine site. Studies of the relationships of accident and injuries to the effectiveness of safety training, the number of shifts each day at a mine site, and the time elapsed during a shift until an accident occurs have produced ambiguous results, often as a result of analysis of inadequate data.     

Applying data mining techniques to explore factors contributing to occupational injuries in Taiwan's construction industry

Construction accident research involves the systematic sorting, classification, and encoding of comprehensive databases of injuries and fatalities. The present study explores the causes and distribution of occupational accidents in the Taiwan construction industry by analyzing such a database using the data mining method known as classification and regression tree (CART). Utilizing a database of 1542 accident cases during the period 2000–2009, the study seeks to establish potential cause-and-effect relationships regarding serious occupational accidents in the industry. The results of this study show that the occurrence rules for falls and collapses in both public and private project construction industries serve as key factors to predict the occurrence of occupational injuries. The results of the study provide a framework for improving the safety practices and training programs that are essential to protecting construction workers from occasional or unexpected accidents.     

Fatal accidents at railway level crossings in Great Britain 1946-2009

This paper investigates fatal accidents and fatalities at level crossings in Great Britain over the 64-year period 1946–2009. The numbers of fatal accidents and fatalities per year fell by about 65% in the first half of that period, but since then have remained more or less constant at about 11 fatal accidents and 12 fatalities per year. At the same time other types of railway fatalities have fallen, so level crossings represent a growing proportion of the total. Nevertheless, Britain's level crossing safety performance remains good by international standards.The paper classifies level crossings into three types: railway-controlled, automatic, and passive. The safety performance of the three types of crossings has been very different. Railway-controlled crossings are the best-performing crossing type, with falling fatal accident rates. Automatic crossings have higher accident rates per crossing than railway controlled or passive crossings, and the accident rates have not decreased. Passive crossings are by far the most numerous, but many have low usage by road users. Their fatal accident rate has remained remarkably constant over the whole period at about 0.9 fatal accidents per 1000 crossings per year.A principal reason why fatal accidents and fatalities have not fallen in the second half of the period as they did in the first half is the increase in the number of automatic crossings, replacing the safer railway controlled crossings on some public roads. However, it does not follow that this replacement was a mistake, because automatic crossings have advantages over controlled crossings in reducing delays to road users and in not needing staff.Based on the trends for each type of crossing and for pedestrian and non-pedestrian accidents separately, in 2009 a mean of about 5% of fatal accidents were at railway controlled crossings, 52% were at automatic crossings, and 43% were at passive crossings. Fatalities had similar proportions. About 60% of fatalities were to pedestrians.A simple comparison of automatic railway level crossings and signalised road intersections found that in 2005 the numbers of fatalities per 1000 crossings or intersections were similar.     

硝铵炸药真空干燥工艺燃爆事故致灾因素的研究

真空干燥是硝铵炸药生产过程中一道容易发生燃爆事故的重要工序。为研究硝铵炸药真空干燥过程中发生燃爆事故的原因及机理，通过事故案例分析和现场调研，确定了导致燃爆事故的各个基本事件及其逻辑关系，并由此构建以燃爆事故作为顶事件的事故树。采用布尔代数化简事故树，得到87个最小割集和9个最小径集，结果显示每个最小径集包含的基本事件都较多，说明真空干燥工艺安全性较低。通过计算各基本事件的结构重要度并排序，得到结构重要度较大的基本事件，由此推断出导致燃爆事故的主要基本事件，并有针对性地提出相应的改进措施与建议，为企业的安全生产提供参考。     

基于事故树的海岛爆破飞石风险辨识

为帮助海岛爆破工程科学系统化的作业,运用事故树分析法对海岛爆破飞石事故的产生原因进行了分析,建立了爆破飞石事故树图,求出最小割集13个,最小径集8个,得到了基本事件的重要结构度值。结果表明:爆破方案审核不严、现场管理不当等问题是造成海岛爆破飞石事故的主要原因,针对这些基本事件提出了4点预防爆破飞石事故的对策措施,为今后的海岛工程爆破系统作业提供了决策支持。     

基于事故树的海岛爆破飞石风险辨识

为帮助海岛爆破工程科学系统化的作业,运用事故树分析法对海岛爆破飞石事故的产生原因进行了分析,建立了爆破飞石事故树图,求出最小割集13个,最小径集8个,得到了基本事件的重要结构度值。结果表明:爆破方案审核不严、现场管理不当等问题是造成海岛爆破飞石事故的主要原因,针对这些基本事件提出了4点预防爆破飞石事故的对策措施,为今后的海岛工程爆破系统作业提供了决策支持。     

Using speeding detections and numbers of fatalities to estimate relative risk of a fatality for motorcyclists and car drivers

Precise estimation of the relative risk of motorcyclists being involved in a fatal accident compared to car drivers is difficult. Simple estimates based on the proportions of licenced drivers or riders that are killed in a fatal accident are biased as they do not take into account the exposure to risk. However, exposure is difficult to quantify. Here we adapt the ideas behind the well known induced exposure methods and use available summary data on speeding detections and fatalities for motorcycle riders and car drivers to estimate the relative risk of a fatality for motorcyclists compared to car drivers under mild assumptions. The method is applied to data on motorcycle riders and car drivers in Victoria, Australia in 2010 and a small simulation study is conducted.     

Farm work related fatalities among adults in Victoria, Australia: the human cost of agriculture

The purpose of this study was to review the patterns of, and trends in, farm work related fatalities among adults in one Australian state for the period 1985-1996. Fatality data was provided by the Victorian Workcover Authority Health and Safety Division. Trends were determined using regression techniques assuming a Poisson error structure for annual fatality rates. Results showed an annual average of eight deaths. Males, and those 60 years and over, were over-represented, compared to persons employed. Tractor incidents were the most common type of fatality (72%), with tractor roll overs accounting for 61% of all tractor incidents. Non tractor fatalities included being hit by a falling object and transport incidents. Statistical trend analyses revealed a non significant decrease in the tractor roll over fatality rate, and significant increases in the all farm (P = 0.004) and non tractor fatality rates (P = 0.036). The 3 year moving average rate for non tractor farm fatalities has increased to the point where it exceeds that for tractor roll over fatalities, and is approaching that for all tractor fatalities. Changes within the agricultural industry, coupled with the ageing of the farm workforce, appear to placing Victorian farmers at increased risk of farm work related death.     

Preferences for lives, injuries, and age: A stated preference survey

One of the more difficult ethical questions from a public decision-making perspective is whether the estimation of benefits from risk reducing projects should be influenced by factors such as age groups and risk domains. For example, should a project that saves the lives of elderly people be assigned a more different benefit value in cost-benefit analyses than one that saves the same number of children's lives? This paper examines the preferences of the general public in Sweden on these issues. We design a choice experiment in which subjects are required to make six pair-wise choices where the characteristics of each choice are accident type (fire and traffic), number of fatalities and serious injuries avoided, and age of those saved (5–15-, 35–45- and 65–75-year-olds). We find that avoiding the fatality of one 5–15-year-old is equivalent to avoiding 1.4 fatalities of 35–45-year-olds. Likewise, avoiding the fatality of one 5–15-year-old is equivalent to avoiding 3.3 fatalities of 65–75-year-olds. We find no significant differences between the causes of accident. One avoided fatality is found to be equivalent to around 3.5 avoided severe injuries, which is lower than the official value of 6 used by the Swedish Road Administration.     

The covariance between the number of accidents and the number of victims in multivariate analysis of accident related outcomes

In this study some statistical issues involved in the simultaneous analysis of accident related outcomes of the road traffic process are investigated. Since accident related outcomes like the number of victims, fatalities or accidents show interdependencies, their simultaneous analysis requires that these interdependencies are taken into account. One particular interdependency is the number of fatal accidents that is always smaller than the number of fatalities as at least one fatality results from a fatal accident. More generally, when the number of accidents increases, the number of people injured as a result of these accidents will also increase. Since dependencies between accident related outcomes are reflected in the variance-covariance structure of the outcomes, the main focus of the present study is on establishing this structure. As this study shows it is possible to derive relatively simple expressions for estimates of the variances and covariances of (logarithms of) accidents and victim counts. One example reveals a substantial effect of the inclusion of covariance terms in the estimation of a confidence region of a mortality rate. The accuracy of the estimated variance-covariance structure of the accident related outcomes is evaluated using samples of real life accident data from The Netherlands. Additionally, the effect of small expected counts on the variance estimate of the logarithm of the counts is investigated.     

A hybrid approach for identification of root causes and reliability improvement of a die bonding process—a case study

This paper presents an industrial case study on reliability improvement of the die bonding machine in the semiconductor industry. A hybrid approach combining dynamic analysis, process decomposition, and a structured fault tree was used to analyze the die bonding process. Firstly, the process was analyzed technically and decomposed into several stages according to different motions. Then, the die movement and force balance at each stage were analyzed according to physical laws, to identify the root causes of die rotation. A structured fault tree was then constructed to trace all possible causes and effects. A qualitative approach was used to identify critical events (root causes) for further analysis. Experiments were conducted to modify the bonding process to reduce the effects of the critical events. Finally, further process modification was proposed for simplification of the fault tree. This case study combined the knowledge in control and reliability engineering and presented a hybrid approach, which is very useful for practising engineers.     

State of Practice of Construction Site Safety in the USA

The construction industry has long been plagued with a high number of fatalities in the USA. Much safety improvements have been made after the USA Congress passed the Occupational Safety and Health Act in 1970. However, this industry still suffers from a disproportionately high rate of work-related fatalities in comparison to other industries. To provide a holistic view of current construction safety practices and corresponding performance, this paper reviews statistics of construction fatalities and their causes. It then presents efforts led to prevent work-related accidents and injuries by the federal safety agencies and the industry. Additionally, advantages and limitations of current practices in terms of construction safety have been discussed along with promotion of aspects in construction work environment.     

Bayesian-network-based safety risk assessment for steel construction projects

There are four primary accident types at steel building construction (SC) projects: falls (tumbles), object falls, object collapse, and electrocution. Several systematic safety risk assessment approaches, such as fault tree analysis (FTA) and failure mode and effect criticality analysis (FMECA), have been used to evaluate safety risks at SC projects. However, these traditional methods ineffectively address dependencies among safety factors at various levels that fail to provide early warnings to prevent occupational accidents. To overcome the limitations of traditional approaches, this study addresses the development of a safety risk-assessment model for SC projects by establishing the Bayesian networks (BN) based on fault tree (FT) transformation. The BN-based safety risk-assessment model was validated against the safety inspection records of six SC building projects and nine projects in which site accidents occurred. The ranks of posterior probabilities from the BN model were highly consistent with the accidents that occurred at each project site. The model accurately provides site safety-management abilities by calculating the probabilities of safety risks and further analyzing the causes of accidents based on their relationships in BNs. In practice, based on the analysis of accident risks and significant safety factors, proper preventive safety management strategies can be established to reduce the occurrence of accidents on SC sites.     

基于事故树分析的露天爆破飞散物预防研究

为了防止露天爆破飞散物事故的发生,确保爆破施工安全,根据露天爆破作业流程,分析了爆破飞散物产生原因,建立了事故树模型,在此基础上进行了定性分析,求出事故树最小割集为15个,最小径集为4个;得到了结构重要度排序,提出了爆破飞散物事故的对策措施,可为今后的爆破设计、施工和安全管理提供参考。     

基于事故树分析的露天爆破飞散物预防研究

为了防止露天爆破飞散物事故的发生,确保爆破施工安全,根据露天爆破作业流程,分析了爆破飞散物产生原因,建立了事故树模型,在此基础上进行了定性分析,求出事故树最小割集为15个,最小径集为4个;得到了结构重要度排序,提出了爆破飞散物事故的对策措施,可为今后的爆破设计、施工和安全管理提供参考。     

Risk and preventive factors for fatalities in All-terrain Vehicle Accidents in New Zealand

All-Terrain Vehicles (ATVs) have been used in agriculture for a few decades now. Yet despite their invaluable contribution to the productivity of the agricultural industry they are associated with a large number of accidents, many of which result in a severe or fatal outcome. The main objective of this study was to identify the risk factors for ATV-related fatal injuries in order to support the design of effective interventions. Using data held by the Department of Labour, the current study analysed 355 cases of serious harm accidents associated with ATVs including 45 fatalities. The findings suggest that injuries are more likely to occur when accidents involve any of the following: children under the age of 10; four-wheel drive ATVs; driving downhill; driving on a sealed road; driving backwards; or if the ATV rolls sideways. A fatal outcome is more likely to occur when ATV accidents end up with the vehicle rolling over and pinning the driver underneath. Fatalities were also associated with injuries to the head, neck and chest. Being employed; and/or having formal training; and/or having brakes and tyres well maintained on the ATV; and/or having no fluid load on the ATV reduced the risk for fatality. Since the likelihood of a fatal outcome was found to be related to human behaviour and ATV rollover, it is suggested that interventions should mainly address these two issues.     

Compatibility problems in frontal, side, single car collisions and car-to-pedestrian accidents in Japan.

Compatibility problems in car-to-car frontal, side, single car and car-to-pedestrian collisions in Japan are discussed using traffic accident data. The number of serious and fatal injuries is investigated for the subject car and other cars, which are categorized by their class and mass. The aggressivity of the cars is calculated by the number of fatalities, fatality rates and by the number of car registrations. The results show that in car-to-car frontal collisions, cars with a mass of 1150 kg are the most compatible among the current car population. In both car-to-car frontal and side collisions, the sports utility vehicle and mini car are found to be the most incompatible car types with high and low aggressivity, respectively. On the other hand, the accident data show that the wagon and midsize sedan are the most compatible car types. The compatibility of fixed objects in the road environment with cars and cars with pedestrians is also discussed. In a single car collision with a fixed object, the guardrail is the most compatible object and can reduce the fatality rate on prefecture roads by about 60%. The front geometry of the car has large effect on compatibility with a pedestrian.     

Fatal train accidents on Europe's railways: 1980-2009

This paper presents an analysis of fatal train accident rates and trends on Europe's main line railways from 1980 to 2009. The paper uses a new set of data for the European Union together with Norway and Switzerland, assembled partly under the auspices of the European Railway Agency and partly on the author's own account. The estimated overall trend in the number of fatal train collisions and derailments per train-kilometre is −6.3% per year from 1990 to 2009, with a 95% confidence interval of −8.7% to −3.9%. The estimated accident rate in 2009 is 1.35 fatal collisions or derailments per billion train-kilometres, giving an estimated mean number of fatal accidents in 2009 of 6.0. The overall number of fatalities per fatal accident in 1990–2009 is 4.10, with no apparent long term change over time, giving an estimated mean of 24.6 fatalities per year in train collisions and derailments in 2009. There are statistically significant differences in the fatal train accident rates and trends between the different European countries, although the estimates of the rates and trends for many individual countries have wide confidence limits. The distribution of broad causes of accidents appears to have remained unchanged over the long term, so that safety improvements appear to have been across the board, and not focused on any specific cause. The most frequent cause of fatal train collisions and derailments is signals passed at danger. In contrast to fatal train collisions and derailments, the rate per train-kilometre of serious accidents at level crossings remained unchanged in 1990–2009. The immediate causes of most of the serious level crossing accidents are errors or violations by road users.