Crash causes human

Table 16-3. Percent of primary crash-causing human errors attributed to the riders and the drivers in the MAIDS (ACEM, 2004).

The role of speeding as a direct crash cause was probably first analyzed in a detailed and comprehensive manner by Treat et al (1977). In this study, described in detail in Chapter 17, a representative sample of more than 2,000 police-reported crashes was analyzed by crash investigators at the crash sites, and 420 of them were further analyzed by multidisciplinary teams. A cause was defined as an event or action whose absence would have prevented the crash, all other things being equal. Furthermore, a human cause was cited if the causal behavior was a deviation from the normal or expected behavior of the average driver. Thus, speed would not be cited in a crash of a speeding vehicle imless the speed deviated from the speed expected at that site under the conditions that prevailed and the crash would not have occurred had the speed been as expected. With this approach to causation, the study estimated excessive speed to be a definite cause in 7-8 percent of the crashes and a probable cause in an additional 13-16 percent of the crashes. 

Figure 17-5, The percent of crashes caused by human, environment, and vehicle causes, at the probable and definite levels, based on the on-site and in-depth crash analyses, and (bottom) the relative proportions of combinations of these causes. Because crashes can have more than one cause, the totals add up to more than 100% (from Treat et aL, 1979).

Figure 17-6. A comparison of the percent of crashes caused by human, environment, and vehicle defects or failures in England (upper number in each circle) and in the U.S. (lower number in each circle) (from Rumar, 1985, with kind permission of Springer Science and Business Media).

Using speed as a crash cause example was not done by chance. It was picked because speed is one behavior or human factor that can be (relatively easily) observed both in crash data and in traffic flow data. Environmental and vehicle factors can also be obtained in both types of data and are prime candidates for evaluation via the statistical approach. Other measures are more difficult. For example, alcohol involvement in crashes can be assessed if alcohol levels are obtained from the crash involved drivers (not too difficult to do) and from the general traffic population (much more difficult since it requires random stopping of drivers to check for their alcohol levels - even if they did not commit any traffic violation). Still other behaviors are practically impossible to evaluate statistically. Unfortunately the behaviors that fall into this category are the most frequent ones to emerge in the clinical evaluations attentional, perceptual, and decision failures. They are difficult to ascertain in the crash data (and are typically absent in police crash reports), and absolutely impossible to determine from the traffic population data. 

Given the implication of driver inattention as a major human crash cause in clinical in-depth analyses, and the recent demonstration of the crash risk from cell-phone related inattention (see Chapter 13), an interesting challenge in the 100-car study was to extract information on the causal roles of inattention and distraction fi-om these data without resorting to the drivers ... 

Appendix HI, of WASH-1400 presents a database from 52 references that were used in the study. It includes raw data, notes on test and maintenance time and frequency, human-reliability estimates, aircraft-crash probabilities, frequency of initiating events, and information on common-cause failures. Using this information, it assesses the range for each failure rate. 

A site-specific Phase 1 QRA for a baseline incineration system at Pueblo was prepared and published in 1998 (SAIC, 1998). The causes of potential accidents considered included failures of equipment, human error, and external phenomena such as earthquakes and airplane crashes. Intentional acts, such as sabotage, were not included, nor were nonagent health risks (which will be covered in the HRA). The Phase 1 QRA concluded that the probability of one or more public fatalities from operation of the baseline system is very much lower than the risk of storing the stockpile for 20 years. However, the probability of fatalities at Pueblo under either scenario was estimated to be very much lower than at the other baseline sites (Table 4-1). 

Risk is the probability of harm or loss and can be considered to be a product of the probability and the severity of specific consequences. Risk, as it relates to hazardous wastes and groundwater contamination, may be defined as the chance that humans or other organisms will sustain adverse effects from exposure to these environmental hazards. Risk is inherent in the life of all organisms—humans, animals, and plants. Tornadoes, landslides, hurricanes, earthquakes, and other natural disasters carry a risk of injury or death to any living thing in their path. Similarly, human-caused risks such as automobile accidents, plane crashes, and nuclear disasters occur with varying levels of severity. 

Protection of a technical installation from the possible consequences of an airplane crashing into the installation may be of importance in cases where a high hazard potential for human beings and structures may be expected. Here it is necessary to start with the assumption that practically any technical installation above ground can be hit by an airplane or airplane debris. Fuel fires caused by the crash may result in extensive damage in technical installations. 

Accident reports, with perfect 20-20 hindsight, often blame the pilot-operator. There were less than 3 minutes between receipt of the incomprehensible mach speed ratio and rudder trim alarms, and the crash into the sea. This accident was caused by poor design of the human-machine interface, which was then compounded by pilot errors - and not the other way round. 

Sustainable Safety set out to prevent (serious) crashes and when this cannot be achieved, to reduce the risk of serious injury to near zero. The proverb man is the measure of all things was taken as a guideline to achieve these goals. This philosophy sees the human being as not only the centre player in road traffic, but also as the most important cause of unsafe situations. The human measure is determined by two characteristics ... 

This study evaluates the consequences (c) from four dimensions human impacts, financial impacts, operational impacts and disruptions to vehicular traffic. The human dimension (c ) deals with the possibility of injuries caused by projection of manhole covers and where they crash land, and bums of at least the second degree due to exposure to incident energy from an are flash. The financial dimension (cj) is about any kind of monetary compensation related to an accident occurring. The operational dimension (cj corresponds to the impact on the supply operation of the electricity distribution company (downtime). Finally, the dimension of disrap-tion to traffic (c,) is evaluated by the process of how traffic jams form on the streets around the accident area. The consequence models are described in details in Garcez Almeida (2013, 2014). 

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