Monotony effects of the work of motormen dlring high-speed train operation.

The results of investigations done in 1965, 1966, and 1972 on the workload of motormen of high-speed trains operating on railroads with maximum speeds of 210 km/hr were compared in an attempt to discuss the physiological implications of the driving task. The driving time of a 515 km section was 4 hr in 1965 and was lowered to 3 hr 10 min since 1966 for the fastest super-express trains. The mean heart rate was maintained around 80 beats/min during the entire driving period in 1965, but declined gradually in 1966 or 1972. Although in 1966 the operations at constant high speed appeared to favor cerebral activities, drivers in the 1972 investigation not only showed lowered perceptual and choice reaction performances but also experienced significant increase in errors in detecting signal tones given as a subsidiary task. Polygraphic recordings in 1972 indicated that drivers sometimes fell into drowsing of short duration intermittently, accompanied by temporary drop in heart rate, absence of controller action, and increase of detection errors. These effects were dominant in periods after 90 min of driving. The need to reduce the monotomy effects during underloaded train driving is suggested.     

Urban commuting: crowdedness and catecholamine excretion.

Male passengers regularly commuting by train on the Stockholm-Nyn?shamn line were investigated on two morning trips to Stockholm. These trips were made under different levels of crowding, before (Trip 1) and after (Trip 2) a period of gas rationing during the oil crisis in 1974. However, seats were available for almost everyone during both trips. One group of subjects boarded the train at its first stop (Nyn?shamn), the other midway on its route (V?sterhaninge). Physiological reactions were assessed from the rate of catecholamine excretion in urine and subjective experiences were measured by self-ratings. The results showed that feelings of discomfort grew more intense as the train approached Stockholm and the number of passengers increased. Perceived crowdedness increased as the square of the number of passengers. During both trips the subjects from Nyn?shamn (longer trip) had a lower rate of adrenaline and noradrenaline excretion on the train than those from V?sterhaninge. Furthermore, it was found that the rate of adrenaline excretion was higher for both groups during Trip 2, when the train was more crowded. The results support previous findings indicating that the stress involved in travelling by train varies more with the social and ecological conditions of the trip than with its length or duration.     

Seasonal variation of falling asleep while driving: An examination of fatal road accidents

Road accidents related to sleep show a clear time-of-day pattern. Following the previous finding that such accidents in Finland happen more often (absolutely and relatively) during the summer months, especially during the afternoon, the main aim of this study was to reveal the factors behind such seasonality. The data included the computerized database of the Finnish fatal road accident investigation system restricted to nonprofessional, nonintoxicated car drivers (N=1464) and sample of the original folders (N=101). The results of the analysis on the sample of the original folders showed that investigation teams adequately documented and explained their decisions concerning falling-asleep accidents and that the observed seasonality is a real phenomenon, not a result of bias of the teams. With the exception of 26-35-year-olds, men of all of the other age groups had a notable absolute and relative increase of sleep-related accidents in the summer. Young male drivers (≤25 yrs), followed by the oldest group (≥66 yrs) had the highest increase in the absolute number of sleep-related accidents between the summer and winter months, while the relative change was the highest for ages 56-65. Women showed similar trends. A detailed analysis of 44 cases of summer afternoon falling-asleep accidents revealed that many drivers were engaged in unusual activities the day or night before the accident. The findings are discussed in relation to different driving and lifestyle habits between seasons, including sleep quality.     

Seasonal Variation of Falling Asleep while Driving: An Examination of Fatal Road Accidents

Road accidents related to sleep show a clear time‐of‐day pattern. Following the previous finding that such accidents in Finland happen more often (absolutely and relatively) during the summer months, especially during the afternoon, the main aim of this study was to reveal the factors behind such seasonality. The data included the computerized database of the Finnish fatal road accident investigation system restricted to nonprofessional, nonintoxicated car drivers (N=1464) and sample of the original folders (N=101). The results of the analysis on the sample of the original folders showed that investigation teams adequately documented and explained their decisions concerning falling‐asleep accidents and that the observed seasonality is a real phenomenon, not a result of bias of the teams. With the exception of 26–35‐year‐olds, men of all of the other age groups had a notable absolute and relative increase of sleep‐related accidents in the summer. Young male drivers (≤25 yrs), followed by the oldest group (≥66 yrs) had the highest increase in the absolute number of sleep‐related accidents between the summer and winter months, while the relative change was the highest for ages 56–65. Women showed similar trends. A detailed analysis of 44 cases of summer afternoon falling‐asleep accidents revealed that many drivers were engaged in unusual activities the day or night before the accident. The findings are discussed in relation to different driving and lifestyle habits between seasons, including sleep quality.     

Ruptured Abdominal Aortic Aneurysms: Surgical Treatment

The records of 62 consecutive patients with ruptured abdominal aortic aneurysms were analyzed to determine what factors contribute to lower mortality. Survival was directly related to the immediate preoperative hemodynamic status of the patients. In 18 cases in which operation was carried out with patients stable, 83 percent of the patients survived. Even if shock was present by the time of operation (37 cases), a 68 percent survival rate was achieved. Cardiac arrest occurred before obtaining aortic control in seven patients and one survived.Survival rates were increased if certain preoperative, operative and postoperative guidelines were followed. Since the combined operative mortality and late graft failure rate in 125 elective aneurysmectomies done during the same decade was under 5 percent, all abdominal aortic aneurysms with few exceptions should be surgically treated before rupture occurs.     

Hang-gliding accidents.

Seventy-five known hang-gliding accidents causing injury to the pilot occurred in the Tyrol during 1973-6. Most occurred in May, June, or September and between 11 am and 3 pm, when unfavourable thermic conditions are most likely. Thirty-four accidents happened during launching, 13 during flight, and 28 during landing, and most were caused by human errors--especially deficient launching technique; incorrect estimation of wind conditions, altitude, and speed; and choice of unfavourable launching and landing sites. Eight pilots were moderately injured, 60 severely (multiply in 24 cases), and seven fatally; fractures of the spine and arms predominated. Six of the 21 skull injuries were fatal. The risk of hang-gliding seems unjustifiably high, and safety precautions and regulations should be adopted to ensure certain standards of training and equipment and to limit flying to favourable sites and times.     

Contribution of alcohol to deaths in road traffic accidents in Tayside 1982-6

In Britain the precise number and relative proportions of deaths among drivers, passengers, and pedestrians in road traffic accidents related to alcohol are not known. These data were obtained in Tayside by cross matching police accident records with blood alcohol concentrations at necropsy. Of 71 alcohol-related deaths 30 were the drivers (or motorcyclists) themselves, nine were their passengers, 23 were pedestrians with raised blood alcohol concentrations, and nine were innocent victims.The high blood alcohol concentrations of the intoxicated drivers, passengers, and pedestrians, which may point to alcoholism, suggest that publicity campaigns will be of little value in reducing the number of deaths in road traffic accidents related to alcohol. The time at which these accidents occurred was related to licensing hours, and this should be taken into account when considering changes in licensing laws.     

Graph analysis of functional brain network topology using minimum spanning tree in driver drowsiness

A large number of traffic accidents due to driver drowsiness have been under more attention of many countries. The organization of the functional brain network is associated with drowsiness, but little is known about the brain network topology that is modulated by drowsiness. To clarify this problem, in this study, we introduce a novel approach to detect driver drowsiness. Electroencephalogram (EEG) signals have been measured during a simulated driving task, in which participants are recruited to undergo both alert and drowsy states. The filtered EEG signals are then decomposed into multiple frequency bands by wavelet packet transform. Functional connectivity between all pairs of channels for multiple frequency bands is assessed using the phase lag index (PLI). Based on this, PLI-weighted networks are subsequently calculated, from which minimum spanning trees are constructed—a graph method that corrects for comparison bias. Statistical analyses are performed on graph-derived metrics as well as on the PLI connectivity values. The major finding is that significant differences in the delta frequency band for three graph metrics and in the theta frequency band for five graph metrics suggesting network integration and communication between network nodes are increased from alertness to drowsiness. Together, our findings also suggest a more line-like configuration in alert states and a more star-like topology in drowsy states. Collectively, our findings point to a more proficient configuration in drowsy state for lower frequency bands. Graph metrics relate to the intrinsic organization of functional brain networks, and these graph metrics may provide additional insights on driver drowsiness detection for reducing and preventing traffic accidents and further understanding the neural mechanisms of driver drowsiness.     

200 injuries caused by playground equipment.

Two-hundred children with injuries caused by playground equipment were studied. Whereas only about 9% of the total casualty attendances are for fractures, 26-5% (53) of these children had fractures. The climbing frame and the slide seemed to be associated with more severe injuries than the swing or other equipment, but more cases need to be studied to confirm this. The youngest children were at particular risk on equipment such as the wooden rocking horse or roundabout, when the speed of operation could be controlled by older children. Many of the injuries to the very youngest children occurred when they were walking behind a moving swing. Faulty equipment did not seem to be a major factor in causing accidents, but the use by older children of apparatus designed for young ones led to accidents. There was supervision, either at home, in a school playground, or in a park, in 62% of the cases. Many of the accidents were the result of the normal desire of children for experimentation and adventure.     

Lessons about sleepiness and driving from the Selby rail disaster case: R v Gary Neil Hart

In April 2003, near the town of Selby in North Yorkshire, England, a motor vehicle went off the road to cause a train collision, killing 10 and injuring more than 70 people. The driver of the vehicle, Gary Neil Hart, had allegedly fallen asleep while driving, and was charged and subsequently convicted of causing death by dangerous driving. Evidence from an expert witness was led by the prosecution to establish that Hart had in fact fallen asleep, and that prior to falling asleep, he knew (or ought to have known) that he was at risk of falling asleep but nevertheless continued to drive. The issue of whether and to what extent individuals are aware that they are about to fall asleep has significant implications for criminal prosecutions. Generally, the definition of a criminal offense includes a mental element such as intent or knowledge. Therefore, it is imperative that issues such as whether in every individual there is forewarning of sleep and the degree to which individuals are able to self-assess their ability to continue driving under conditions of extreme sleepiness must be resolved. Sleepiness is now regarded as the largest identifiable and preventable cause of accidents in all modes of transportation. Litigation for such accidents is likely to increase, and therefore it is of great importance that further research be undertaken to examine the process of falling asleep, especially the subjective experiences immediately preceding sleep.     

Occupational performance of a paced secondary task under conditions of sensory deprivation. I. Heart rate changes in train drivers as a result of monotony

Twelve experienced train drivers were asked to operate the train function safety circuit (SIFA)--a paced secondary motor task which is expected to guarantee the driver's fitness for service on engines of the German Federal Railway--under laboratory conditions of extreme monotony. In spite of massive decreases in vigilance as shown by theta-activity in the EEG, all subjects were able to operate the device without major errors. A prerequisite for adequate performance is an EEG-defined arousal reaction, which is synchronized with the SIFA cycles. For 7 subjects the time-related cross-correlation coefficients between SIFA operation, alpha-activity (indicative of alertness), theta-activity (indicative of reduced vigilance), and heart rate were calculated. The central-nervous arousal found in the EEG corresponded to distinct increases in heart rate. The moments of SIFA operation after phases of light sleep correlated significantly and positively with increases in heart rate. These increases constituted a physiological overcompensation as far as the physical readiness was concerned which reached its peak after the task had been performed satisfactorily, constituting additional and superfluous occupational stress. The results of this study indicate clearly that monotony stress is not a result of occupational monotony itself, but the result of the physiological effort which is required in order to regain a level of alterness which allows adequate performance under monotonous conditions.     

Attention Deficit Hyperactivity Disorder Symptoms,Sleepiness and Accidental Risk in 36140 Regularly Registered Highway Drivers

Background

Attention Deficit Hyperactivity Disorder (ADHD) is a frequent neurodevelopmental disorder that increases accidental risk. Recent studies show that some patients with ADHD can also suffer from excessive daytime sleepiness but there are no data assessing the role of sleepiness in road safety in patients with ADHD. We conducted an epidemiological study to explore sleep complaints, inattention and driving risks among automobile drivers.

Methods and Findings

From August to September 2014, 491186 regular highway users were invited to participate in an Internet survey on driving habits. 36140 drivers answered a questionnaire exploring driving risks, sleep complaints, sleepiness at the wheel, ADHD symptoms (Adult ADHD Self-Report Scale) and distraction at the wheel. 1.7% of all drivers reported inattention-related driving accidents and 0.3% sleep-related driving accidents in the previous year. 1543 drivers (4.3%) reported ADHD symptoms and were more likely to report accidents than drivers without ADHD symptoms (adjusted OR = 1.24, [1.03–1.51], p < .021). 14.2% of drivers with ADHD symptoms reported severe excessive daytime sleepiness (Epworth Sleepiness Scale >15) versus 3.2% of drivers without ADHD symptoms and 20.5% reported severe sleepiness at the wheel versus 7.3%. Drivers with ADHD symptoms reported significantly more sleep-related (adjusted OR = 1.4, [1.21–1.60], p < .0001) and inattention-related (adjusted OR = 1.9, [1.71–2.14], p<0001) near misses than drivers without ADHD symptoms. The fraction of near-misses attributable to severe sleepiness at the wheel was 4.24% for drivers without ADHD symptoms versus 10,35% for drivers with ADHD symptoms.

Conclusion

Our study shows that drivers with ADHD symptoms have more accidents and a higher level of sleepiness at the wheel than drivers without ADHD symptoms. Drivers with ADHD symptoms report more sleep-related and inattention-related near misses, thus confirming the clinical importance of exploring both attentional deficits and sleepiness at the wheel in these drivers. Road safety campaigns should be improved to better inform drivers of these accidental risks.     

Traffic Accidents—Epidemiology and Medical Aspects of Prevention

Injuries and deaths from traffic accidents are a public health problem of epidemic proportions and justify intensive epidemiological research. The human factor is responsible for the majority of traffic accidents. The literature concerning the human factor is reviewed, and it is concluded that psychosocial influences are most important, though medical conditions may be responsible for 3 to 4% of accidents. Problems concerning the medical examination of drivers are discussed and the need is emphasized to find some means of removing from the road those drivers who continue to drive in spite of repeated medical advice not to do so. Some of the medical conditions influencing driver safety are discussed. It is recommended that each Division of The Canadian Medical Association should publish a guide for physicians who examine drivers. The advantages of a uniform guide in Canada are stressed.     

Bicycle accidents in childhood.

The results of a 10 year study of bicycle fatalities and an eight year study of serious non-fatalities are reported for urban Brisbane (population 1,000,000). There were 845 serious non-fatal bicycle accidents and 46 fatalities during the study. Boys were involved in 86% of accidents. Boys have an accident rate of 134.21 per 100,000 population at risk and a fatality rate of 5.06 per 100,000 at risk. Serious bicycle accidents have increased by 50% in this decade; but considering fatal cases alone, no secular trend was evident over the 10 year period of the study. This suggests that an increase in the overall rate of bicycle accidents has been in part compensated by less serious injuries. In 70% of fatalities children had head injuries, and 87% of fatalities followed a collision between a cyclist and a motor vehicle or a train. Bicycle accidents on the roads most commonly occur to boys aged between 12 and 14 years on a straight road at "mid-block" between 3 and 5 pm in clear weather conditions and in daylight. It is concluded that injuries and fatalities after bicycle accidents can be reduced by protecting children''s heads, separating child cyclists from other road traffic, or educating and training both cyclists and other road users in safe behaviour. The compulsory use of helmets and the restriction of access to the roads by child cyclists to reduce injuries are, however, still controversial in many areas.     

Foraging by little auks in the distant marginal sea ice zone during the chick-rearing period

During the chick-rearing period, little auks Alle alle adopt a bimodal foraging strategy, alternating long trips with several short ones. It has been postulated that they reach more remote areas during long feeding trips than during short ones. However, the range of their foraging flights has never actually been measured. The aims of this study were to find the exact location of the little auk feeding grounds and to investigate whether they reach remote areas during long foraging trips using miniature GPS and temperature loggers. The study was conducted in 2009 in Magdalenefjorden (79°34′N, 11°04′E), one of the main breeding grounds of little auks on Spitsbergen. The temperature logger records indicated that during short trips, little auks visit warmer waters (situated close to the colony) than during long ones. The tracks of two GPS-equipped birds indicated that during long trips little auks foraged in the distant, food-abundant marginal sea ice zone, at least 100 km away from the colony. During long trips, birds make several stops at sea, perhaps sampling the foraging area with respect to prey distribution. Since food conditions near the studied colony are usually suboptimal, little auks may be exploiting distant feeding areas to compensate for the poorer-quality food available at nearby foraging grounds. The extended duration of long foraging trips may enable birds to collect food for chicks on food-abundant, remote foraging grounds as well as acquire, process and excrete food needed for self-maintenance, reducing the costs of flight to the colony.     

Sleep related vehicle accidents.

OBJECTIVES--To assess the incidence, time of day, and driver morbidity associated with vehicle accidents where the most likely cause was the driver falling asleep at the wheel. DESIGN--Two surveys were undertaken, in southwest England and the midlands, by using police databases or on the spot interviews. SUBJECTS--Drivers involved in 679 sleep related vehicle accidents. RESULTS--Of all vehicle accidents to which the police were summoned, sleep related vehicle accidents comprised 16% on major roads in southwest England, and over 20% on midland motorways. During the 24 hour period there were three major peaks: at around 0200, 0600, and 1600. About half these drivers were men under 30 years; few such accidents involved women. CONCLUSIONS--Sleep related vehicle accidents are largely dependent on the time of day and account for a considerable proportion of vehicle accidents, especially those on motorways and other monotonous roads. As there are no norms for the United Kingdom on road use by age and sex for time of day with which to compare these data, we cannot determine what the hourly exposure v risk factors are for these subgroups. The findings are in close agreement with those from other countries.     

Motor vehicle driving among diabetics taking insulin and non-diabetics.

OBJECTIVE--To determine whether rates of road traffic accidents were higher in diabetics treated with insulin than in non-diabetic subjects. DESIGN--Controlled, five year retrospective survey. SETTING--Diabetic, dermatology, and gastroenterology outpatient clinics. PATIENTS--596 Diabetics treated with insulin (354 drivers) aged 18-65 attending two clinics and 476 non-diabetic outpatients (302 drivers). MAIN OUTCOME MEASURES--Rates of accidents in diabetic and non-diabetic subjects. RESULTS--A self completed questionnaire was used to record age, sex, driving state, and rates of accidents and convictions for motoring offences among diabetic and non-diabetic volunteers. For the diabetic volunteers further information was obtained on treatment, experience of hypoglycaemia, and declaration of disability to the Driving and Vehicle Licensing Centre and their insurance company. Accident rates were similar (81 (23%) diabetic and 76 (25%) non-diabetic drivers had had accidents in the previous five years). A total of 103 diabetic drivers had recognised hypoglycaemic symptoms while driving during the previous year. Only 12 reported that hypoglycaemia had ever caused an accident. Overall, 249 had declared their diabetes to an insurance company. Of these, 107 had been required to pay an increased premium, but there was no excess of accidents in this group. CONCLUSIONS--Diabetic drivers treated with insulin and attending clinics have no more accidents than non-diabetic subjects and may be penalised unfairly by insurance companies.     

Traffic accidents-chronic medical conditions as a cause

From comparatively scanty information, an increased traffic accident risk appears to be associated with several chronic medical conditions including alcoholism, cardiovascular disease, epilepsy, diabetes and mental illness. Further study probably will show that medical handicaps other than alcoholism are a factor in from 5 to 10 per cent of traffic accidents. However, in about half of the accidents caused by heart attacks, the individual has no previous knowledge of his illness, and prevention of the accident would not be possible. A selective program for identifying high risk drivers with medical conditions is feasible and warranted, but a program of mass medical examinations for all drivers is not.A very strong relationship has been shown between drunk driving and traffic accidents, and 50 to 75 per cent of all severe and fatal traffic accidents involve the use of alcohol. However, studies have shown that drivers with alcoholism rather than social drinkers represent the preponderance, but not the entirety, of those who get into trouble. A major reduction in the traffic accident toll may thus depend on the early identification and treatment of alcoholism.     

Complaints of Poor Sleep and Risk of Traffic Accidents: A Population-Based Case-Control Study

Introduction

This study aimed to determine the sleepiness-related factors associated with road traffic accidents.

Methods

A population based case-control study was conducted in 2 French agglomerations. 272 road accident cases hospitalized in emergency units and 272 control drivers matched by time of day and randomly stopped by police forces were included in the study. Odds ratios were calculated for the risk of road traffic accidents.

Results

As expected, the main predictive factor for road traffic accidents was having a sleep episode at the wheel just before the accident (OR 9.97, CI 95%: 1.57–63.50, p<0.05). The increased risk of traffic accidents was 3.35 times higher in subjects who reported very poor quality sleep during the last 3 months (CI 95%: 1.30–8.63, p<0.05), 1.69 times higher in subjects reporting sleeping 6 hours or fewer per night during the last 3 months (CI 95%: 1.00–2.85, p<0.05), 2.02 times higher in subjects reporting symptoms of anxiety or nervousness in the previous day (CI 95%: 1.03–3.97, p<0.05), and 3.29 times higher in subjects reporting taking more than 2 medications in the last 24 h (CI 95%: 1.14–9.44, p<0.05). Chronic daytime sleepiness measured by the Epworth Sleepiness Scale, expressed heavy snoring and nocturnal leg movements did not explain traffic accidents.

Conclusion

Physicians should be attentive to complaints of poor sleep quality and quantity, symptoms of anxiety-nervousness and/or drug consumption in regular car drivers.     

Traffic Accidents—Chronic Medical Conditions as a Cause

From comparatively scanty information, an increased traffic accident risk appears to be associated with several chronic medical conditions including alcoholism, cardiovascular disease, epilepsy, diabetes and mental illness. Further study probably will show that medical handicaps other than alcoholism are a factor in from 5 to 10 per cent of traffic accidents. However, in about half of the accidents caused by heart attacks, the individual has no previous knowledge of his illness, and prevention of the accident would not be possible. A selective program for identifying high risk drivers with medical conditions is feasible and warranted, but a program of mass medical examinations for all drivers is not.A very strong relationship has been shown between drunk driving and traffic accidents, and 50 to 75 per cent of all severe and fatal traffic accidents involve the use of alcohol. However, studies have shown that drivers with alcoholism rather than social drinkers represent the preponderance, but not the entirety, of those who get into trouble. A major reduction in the traffic accident toll may thus depend on the early identification and treatment of alcoholism.