Multiple-vehicle traffic accidents in Hong Kong

‘Multiple-vehicle traffic accident’ refers to a crash between two or more moving objects. Unlike single-vehicle accidents, not all drivers involving in a multiple-vehicle accident are responsible for the occurrence of the event. Accordingly, variables such as road type, speed limit and number of vehicles involved in the accident are expected to play a much more important role in association with injury severity in multiple-vehicle accidents. To study the factors influencing injury severity of multiple-vehicle traffic accidents, a population-based study was conducted. The traffic accident data was obtained from the Traffic Accident Data System (TRADS), which was developed by the Transport Department, Police Force and Information Technology Services Department, Hong Kong. Multiple-vehicle traffic accidents (N = 10,630) occurring during the 2-year period 1999/2000 were considered. Potential risk factors such as district, human, vehicle, safety, environmental and site factors were examined. Categorizing injury severity into “fatal/serious” and “slight”, a stepwise logistic regression model was applied to the population data set. The district board, time of the accident, driver's gender, vehicle type, road type, speed limit and the number of vehicles involved are significant factors influencing the injury severity. Identification of risk factors for severe traffic accidents provides valuable information to help with new and improved road safety control measures.     

ARAMIS project: a comprehensive methodology for the identification of reference accident scenarios in process industries

In the frame of the Accidental Risk Assessment Methodology for Industries (ARAMIS) project, this paper aims at presenting the work carried out in the part of the project devoted to the definition of accident scenarios. This topic is a key-point in risk assessment and serves as basis for the whole risk quantification.

The first result of the work is the building of a methodology for the identification of major accident hazards (MIMAH), which is carried out with the development of generic fault and event trees based on a typology of equipment and substances. The term “major accidents” must be understood as the worst accidents likely to occur on the equipment, assuming that no safety systems are installed.

A second methodology, called methodology for the identification of reference accident scenarios (MIRAS) takes into account the influence of safety systems on both the frequencies and possible consequences of accidents. This methodology leads to identify more realistic accident scenarios. The reference accident scenarios are chosen with the help of a tool called “risk matrix”, crossing the frequency and the consequences of accidents.

This paper presents both methodologies and an application on an ethylene oxide storage.     

On the prevention of accidents and injuries : A comparative analysis of conceptual frameworks

The meaning of prevention has changed as new applications of the concept have appeared. Ideas presented in eleven different conceptual frameworks are compared. Identification of the frameworks took place through searches in databases and relevant literature. Five are general by nature, while six relate to injuries and accidents. All are supported by just a few parameters, the time dimension being the most prominent. Compatibility was established on three additional dimensions: level (individual, organizational or societal); direction (“bottom-up” or “top-down”); and in relation to the trichotomy “host-agent-environment”. An attempt to synthesize all these dimensions into one general model of accident and injury prevention is presented.     

A study of driver experience and vehicle familiarity in accidents

A separate study was performed as part of a major accident investigation project to (1) test the hypothesis that drivers of vehicles involved in investigated accidents had less driving experience than the general driving population, and (2) test the hypothesis that accident involved drivers were less familiar with their vehicles than the general driving population. A Kolmogorov-Smirnov one-tail test was employed to evaluate the differences in the distributions of driver experience and vehicle familiarity between the “accident sample” and a “control sample.” Results indicated that drivers involved in the investigated accidents had less driving experience in general and had less driving experience with the accident vehicles than drivers in the general population. These effects are discussed briefly and further studies are suggested.     

Accidents in family forestry's firewood production

Firewood is commonly used around the world, but little is known about the work involved in its production and associated accidents. The objectives were to identify relationships between accidents and time exposure, workers’ age and sex, equipment used and work activities in family forestry's firewood production. Data from a postal survey in Northern Sweden were compared to a database of injuries in the same region. Most accidents occurred to 50–69 year old men, who also worked most hours. No significant differences in sex and age were found between expected and recorded accident frequencies when calculated from total work hours; however, when calculated using numbers of active persons significant differences were found for both age and sex. Frequency of accidents per unit worked time was higher for machine involving activities than for other activities. Accidents that occurred when using wedge splitter machines were responsible for most of this overrepresentation. Fingers were the most commonly injured body parts. Mean accident rate for the equipment used was 87 accidents per million work hours, and the rate was highest for wedge splitters (122 accidents per million work hours). Exposure to elevated risks due to violation of safety procedures is discussed, as well as possible preventative measures.     

Statistical analyses of highway commercial vehicle accidentst†

In a research program aimed at the assessment of more comprehensive accident analysis methods, new applications of statistical analysis procedures to commercial vehicle accidents have been investigated, and exemplary results obtained [Philipson et al., 1978], A file of some 3000 specially-detailed California Highway Patrol accident reports from two areas of California during a period of about one year in 1975–1976 provided the unique data base for the application. Computer implementation and evaluation through statistical testing of the quality of the data file were first accomplished. Then an exhaustive univariate analysis of the data was conducted to describe the file in detail. Selected sets of dependent and independent variables were then subjected to analyses of association employing contingency table analysis methods. In several cases, acceptable log-linear models to explain the variables' association were thereby established. Vehicle exposure measured in vehicle miles traveled for each vehicle category was introduced into one of the analyses to assess its impact on the set of significant interactions; it was indeed found to be important, albeit accuracy in its estimation was problematical. This estimation was carried out by two independent methods; a “direct” procedure based on a series of linear extrapolations of basic State of California commercial vehicle traffic data, and an “induced” estimation procedure essentially employing only data in the accident reports. The results of the two methods exhibited some common trends, but otherwise differed considerably. The results of the research effort, highlighted in this article, indicated the value of the methods investigated, and so of the detailed accident report files necessary for their use. They also strongly illuminated the areas of greatest difficulty in the application of these methods, basically associated with accident data quality and exposure estimation accuracy, and general directions for their improvement.     

Prediction in road safety studies: An empirical inquiry

Studies about the road safety effect of interventions are usually retrospective quasiexperiments. In these, one key task is to predict what would have been the safety of the treated group without the intervention. Such predictions can be made by several methods, one of which is to use a “comparison group.” We use 26 yearly counts of reported injury accidents for the Canadian provinces to examine which of several simple methods of prediction would have historically predicted best. We find that the use of more data does not always improve prediction. How well one predicts depends not only on the amount of data used but also on the extent to which the prediction method is in accord with the unknown time trend behind the accident counts. We also find that the use of a comparison group to predict is not always better than predicting that this year's count will be the same as last year's. In addition, the intuitive notion that a good comparison group is that which is thought similar to the treated group is too simple. Both similarity and size (as measured by the number of accidents) are important. Moreover, whatever preconceived notions of similarity we had, were contradicted by the data. If the history of accident counts on the treatment group and on several possible comparison groups is available, a simple method to select the most suitable comparison group is suggested.     

Accident rates and types among self-employed private forest owners

Half of all Swedish forests are owned by private individuals, and at least 215,000 people work in these privately owned forest holdings. However, only lethal accidents are systematically monitored among self-employed forest workers. Therefore, data from the registries of the Swedish Work Environment Authority, the Labor Insurance Organization and the regional University Hospital in Umeå were gathered to allow us to perform a more in-depth assessment of the rate and types of accidents that occurred among private forest owners.We found large differences between the registries in the type and number of accidents that were reported. We encountered difficulties in defining “self-employed forest worker” and also in determining whether the accidents that did occur happened during work or leisure time. Consequently, the estimates for the accident rate that we obtained varied from 32 to ≥4300 injured persons per year in Sweden, depending on the registry that was consulted, the definition of the sample population that was used, and the accident severity definition that was employed. Nevertheless, the different registries gave a consistent picture of the types of accidents that occur while individuals are participating in self-employed forestry work. Severe accidents were relatively common, as self-employed forestry work fatalities constituted 7% of the total number of fatalities in the work authority registry. Falling trees were associated with many of these fatal accidents as well as with accidents that resulted in severe non-fatal injuries. Thus, unsafe work methods appeared more related to the occurrence of an accident than the equipment that was being used at the time of the accident (e.g., a chainsaw). Improvement of the workers’ skills should therefore be considered to be an important prevention measure that should be undertaken in this field.The challenges in improving the safety in these smallest of companies, which fall somewhere between the purview of occupational and consumer safety, are exemplified and discussed.     

Willingness to use safety belt and levels of injury in car accidents

In this article, we develop a bivariate ordered Probit model to analyze the decision to fasten the safety belt in a car and the resulting severity of accidents if it happens. The approach takes into account the fact that the decision to fasten the safety belt has a direct causal effect on the category of injury if an accident happens. Our application to a sample drawn from the database of French accident reports in 2003 for three populations of car users (drivers, front passengers, rear passengers) shows that fastening the safety belt is significantly related to a decrease in severe injuries but it shows also that these car users compensate partly for this safety benefit. Furthermore, it is observed that demographic characteristics of car users, as well as transport facilities, play important roles in decisions to fasten safety belts and in the eventual resulting accident injuries.     

A macroscopic impact analysis of the safety efforts case study: Pedestrian fatalities

Any time there are reductions in accidents, advocates of any particular position are quick to claim that it is their “effect” that has improved safety performance. The work in this paper focuses on interpreting a traffic system's performance with respect to a specific type of accident by attributing a change in the number of accidents to the relative contribution of three effects: the activity effect, the safety content effect, and the structure effect. A method is developed and applied to the data sets of pedestrian fatalities that occured in Greece during the period of 1965–1989. The relative contribution of the effects as well as the pattern changes turn out to have a decisive influence. The possible uses and extensions of the method are also discussed.     

Bicycle accidents and injuries: a pilot study comparing hospital- and police-reported data

Bicycle accident and injury data collected by two different samples of North Carolina hospital emergency rooms during the summers of 1985 and 1986 are examined and compared with state police-reported bicycle accident data for the same time periods. Of the 649 emergency room treated bicyclists, 62% were children aged 5-14 and 70% were male. Nineteen percent of the riders suffered moderate or worse injuries (AIS greater than or equal to 2), and 6% were hospitalized. In contrast, less than half of the police-reported accidents involved riders under 15 years of age, 85% of the riders were male, and two-thirds suffered moderate or worse injury. Whereas virtually all of the police-reported accidents involved a motor vehicle, less than a fifth of the emergency room cases did. Only 10% of the emergency room cases were duplicated on the state accident files. It is estimated that 800 children ages 0-19 are hospitalized annually in North Carolina for bicycle-related injuries, and an additional 13,300 children receive emergency room treatment.     

Epidemiology of traffic accidents in a Swedish municipality

Total population injury surveillance was done in an area with a population of over 41,000. All traffic accidents (N = 632) occurring within a 12-month period and requiring medical care were noted, giving a ratio of 15.3 per 1,000. They involved cyclists (38.3%), pillion passengers on cycles (1.9%), pedestrians (29.3%), motorcar drivers (7.8%), motorcar passengers (3.6%), passengers entering or leaving a vehicle (7.3%), mopedists (6.8%), motorcyclists (3.5%), and “others” (1.6%). Children and teenagers predominated in the cycle group; 55% of the males were aged 0–15 years compared with 41% of the females. Women were involved in 65% of the pedestrian accidents; 69% were aged 50 years or more. Of the accidents involving women aged over 50 years, 61% occurred in icy or snowy conditions. The police statistics were incomplete and accounted for only 23% of the total number of people reported injured by the health authorities. In some respects, the accident pattern in the present study differed from that in other comparable studies. The difference is especially great concerning the incidence of traffic accidents, the proportion of young persons involved in cycle accidents, and the number of accidents caused by motorcar drivers who developed sudden illness whilst driving.     

An analysis of biorhythms and their influence on motor vehicle fatalities

The possible effect of proposed cyclic fluctuations of human sensitivity (28 days), intelligence (33 days), and physical (23 days) characteristics on motor vehicle accidents and fatalities was examined. Three methods of calculating these theoretical cycles were also examined. One method, the “Biomate” computer, was found to be unreliable in that it indicated 10.6% more days designated by the theory as critical than were actually present in a 300 case sample. In a sample of 141 motor vehicle fatalities (64 drug-free and 77 drug-associated) no correlation with the theoretical critical days was found for either group beyond that expected from random distribution. No evidence was found to support the increased likelihood of accident involvement on the “critical day” as implied by the concept of the “biorhythm” theory. Several possible sources of error in previously published reports are discussed.     

Road traffic accidents in rich developing countries: The case of Libya

Libya is a rich developing country which suffers the consequences of explosions in both human and vehicle population. This has been accompanied by a heavy toll of deaths, In 1977, road accidents were the cause of 10% of all deaths and 62% of male deaths in the age group 15–25. The rates-per hundred million veh km-of fatalities, injuries and accidents (1980) were 35.202 and 416 respectively. The pedestrian fatality and casualty rates (1977) were high (20,134/100,000 population) especially among the old males over 64 (89,384/100,000 population). In the age group 20–24, casualty rate of drivers was 1256/100,000 driver (1977). Accidents were severe as well. Between 1970–1980 accident severity index was increasing with time and almost doubled by the end of the period reaching 13. Road accidents in Libya do not only represent an important social problem but also an economic one. In 1978, accidents cost the country about $160 million. The factors which affect accident rates and severity are divided into behavioural and structural ones and investigated. There is room for improving traffic safety in Libya. A comprehensive traffic safety program is urgently needed.     

Comparison groups in road safety studies: An analysis

When the safety effect of some treatment is to be estimated, one has to answer the question: “what would have been the ratio of the expected number of accidents ‘before’ and ‘after’ had the treated group been left without treatment? ” In retrospective observational studies, the count of accidents on a “comparison group” is often used to provide an answer. In consequence, the estimate of the safety effect depends on which of several comparison groups is chosen. It is therefore important to have guidance for this choice. The empirical inquiry in the companion paper led to several conclusions. The explanation of what has been noted by the examination of data requires analysis and is taken up in this paper.     

An analysis of safety control effectiveness

The cost of injuries and “accidents” to an organisation is very important in establishing how much it should spend on safety control. Despite the usefulness of information about the cost of a company's accidents, it is not customary accounting practice to make these data available. Of the two kinds of costs incurred by a company through occupational injuries and accidents, direct costs and indirect costs; the direct costs are much easier to estimate. However, the uninsured costs are usually more critical and should be estimated by each company. The authors investigate a general model to estimate the above costs and hence to establish efficient safety control. One construction company has been a pilot for this study. By analysing actual company data for three years, it is found that the efficient safety control cost should be 1.2–1.3% of total contract costs.     

Accident under-reporting among employees: Testing the moderating influence of psychological safety climate and supervisor enforcement of safety practices

We examined accident under-reporting with data from 425 employees employed in 5 industries with above average risk for employee injuries. We expected that rates for unreported accidents would be higher than rates for reported accidents; and that organizational safety climate and perceptions of supervisor enforcement of safety policies would moderate the relationship between unreported accidents and reported accidents. Results showed that the number of unreported accidents was significantly higher than the number of reported accidents. There was an average of 2.48 unreported accidents for every accident reported to the organization. Further, under-reporting was higher in working environments with poorer organizational safety climate or where supervisor safety enforcement was inconsistent. We discuss the implications of these findings for improving accident under-reporting and occupational safety in the workplace.     

Looked-but-failed-to-see-errors in traffic

Danish studies of traffic accidents at priority intersections have shown a particular type of accidents. In these accidents a car driver supposed to give way has collided with a bicycle rider on the priority road. Often the involved car drivers have maintained that they did not see the bicycle until immediately before the collision even though the bicycle must have been clearly visible.

Similar types of accidents have been the subject of studies elsewhere. In literature they are labelled “looked-but-failed-to-see”, because it seems clear that in many cases the car drivers have actually been looking in the direction where the other parties were but have not seen (i.e. perceived the presence of) the other road user. This paper describes two studies approaching this problem.

One study is based on 10 self-reported near accidents. It does show that “looked-but-failed-to-see” events do occur, especially for well experienced drivers. The other study based on Gap Acceptance shows that the car driver acceptance of gaps towards cyclists depends on whether or not another car is present. Hypotheses for driver perception and for accident countermeasures are discussed.     

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.     

A preliminary evaluation of the impact of local accident information on the public perception of road safety

The World Health Organisation (WHO) estimate that road traffic accidents represent the third leading cause of “death and disease” worldwide. A number of countries have, therefore, launched safety campaigns that have reduced their fatalities. In almost every case, however, this reduction has not been matched by a fall in the total frequency of road traffic accidents. Low-severity incidents remain a significant problem. “Attribution error” provides one plausible explanation for this phenomenon. Most drivers believe that they are less likely to be involved in an accident than other motorists. Existing road safety campaigns do little to address this problem; they focus on national and regional statistics that often seem remote from the local experiences of road users. This paper, therefore, describes the design and development of a system to provide the general public with access to information on the location and circumstances of road accidents in a Scottish city. The closing sections describe the initial results from a psychometric study that is intended to determine whether the information provided by such an application will have any impact on individual risk perception.