Dinesh Mohan

Failure properties of passive human aortic tissue. II—Biaxial tension tests

Descending mid-thoracic aortas were obtained from 16 autopsies and biaxial inflation tests performed on the tissue at dynamic (approximately 20 s-1) and quasi-static (approximately 0.01 s-1) strain rates. A bubble inflation technique was developed for this purpose. Extension histories of the specimens were recorded photographically and values of ultimate stresses and extension ratios in biaxial stretch have been calculated. Under conditions of uniform biaxial stretch the tissue consistently failed in a direction perpendicular to the long axis of the aorta and pressure values at failure were greater by a factor of two in the dynamic tests than those in the quasi-static tests.

Road accidents in India

This article discusses traffic accidents and crash patterns in India. It presents 5 tables with the following titles: Trends in growth of vehicles registered and traffic fatalities in India; Vehicles registered in India, Germany, U.S.A. and Japan; Age distribution of road traffic fatalities in India in 1996; Proportion of road users killed at different locations in India; and Proportions of vehicles involved in fatal crashes.

Reducing motor vehicle crash deaths and injuries in newly motorising countries

The United States was the first country to experience deaths and injuries from motor vehicle crashes in large numbers. As other countries motorised, they, too, experienced large numbers of crash deaths and injuries. Early efforts to address this problem were based largely on guesswork, with the principal focus on educating motorists. This simplistic and narrow approach continued for decades, even though the numbers of crash deaths and injuries continued to grow.1 In the 1960s a public health approach to the problem emerged in the United States and other motorised countries. Under this new approach, the available prevention options greatly expanded, and the effectiveness of countermeasures was scientifically evaluated before widespread adoption. This emphasis on evaluation was important because the earlier efforts continued for decades without evaluation, and when some of these programmes were eventually evaluated there was no evidence of effectiveness.2 Today motor vehicle crashes are causing substantial numbers of deaths in countries that are relatively new to motorisation.3 A key question is how these countries can avoid the many unnecessary deaths and serious injuries that occurred in todays motorised countries during the decades that motor vehicle use was rapidly expanding, ineffective countermeasures were in place, and potentially effective countermeasures were being ignored. #### Summary points One consequence of the rapid growth in motor vehicle use in many countries is increasing numbers of crash deaths and injuries To reduce this toll, countries need to adopt a broad array of research based measures Despite being widely advocated as essential safety programmes, driver education or training programmes have not been found to reduce motor vehicle crashes Almost all of the demonstrable gains produced by changing road user behaviour have resulted from properly enforced traffic safety laws In many less motorised countries a disparate mix of road users share the roads, and so …

Conflict analysis for prediction of fatal crash locations in mixed traffic streams

This paper reports the results of a study that explored the relationship between fatal crashes and conflict rates at mid-block on 14 locations in Delhi, India. All locations had a mix of motorized and non-motorized traffic. The sites were selected to represent low, medium and high fatality rates. The analysis was done in two stages. The first stage used recent 3-year statistics along the entire street. The second stage focused on each fatal crash for mid-block segments on those streets. Peak-hour traffic at 14 selected locations was videotaped. Trained observers recorded traffic compositions at mid-block, average space mean speeds by mode and conflicts by type, reactor mode and cause mode. After converting raw conflict counts to rates, site ranking went from high to low conflict rate sites. The studies showed a weak crash-conflict association. Conflict data for various sites were compared for different combinations of conflicts. The comparison revealed that the presence of only a few non-motorized modes is enough to cause conflicts between motorized vehicles and on-road non-motorized vehicles. The study did not provide a conclusive relationship between mid-block conflicts and fatal crash sites. However, the conflict study provided useful insights into the interaction between different traffic entities in the traffic streams of 14 sites. An important conclusion of this study is that a traffic-planning emphasis on studying conflict rates may not result in reducing fatality rates on urban roads along mid-block segments.

War on the roads

The last thing the world needs is another war. Nevertheless, this week the BMJ exposes one more—the war on the worlds roads. But to what extent can the global road trauma epidemic be likened to war? War is often waged by the powerful on the weak. In this case, the interests of pedestrians, cyclists, and other vulnerable road users are pitted against the powers that stand to profit from increasing global motorisation. And there are many millions of casualties. Every day about 3000 people die and 30 000 people are seriously injured on the worlds roads.1 In this issue Nantulya and Reich point out that over 85% of the deaths and 90% of disability adjusted life years lost from road traffic injuries are in low and middle income countries, with pedestrians, cyclists, and bus passengers bearing most of the burden.2 Most of the victims will never own a car, and many are children. Even in the high income countries, poor children are at greatest risk. The existence …

An analysis of road traffic fatalities in Delhi, India

Road use patterns in Delhi, India are very different from those in cities in highly industrialized countries. In Delhi roads are also shared by unmotorized vehicles in large numbers. This study is an attempt to understand fatal crash patterns in Delhi in 1980 using police data. The results indicate that fatality patterns in Delhi are very different from those in highly industrialized countries. Pedestrians, two-wheeler riders and bus commuters comprise 80% of fatalities and motor-vehicle occupants a small minority. It appears that priorities for safety countermeasures in Delhi would have to be significantly different from those in more industrialized high-income countries. Some short-term and long-term measures are suggested in the paper.

Design of safer agricultural equipment: Application of ergonomics and epidemiology

Abstract A vast majority of the worlds workers are employed in agricultural activities and are exposed to a wide variety of hazards. Since agriculture is primarily decentralised activity, it is often difficult to set and implement work safety norms and standards. While standards can be set for equipment manufactured in large factories, it is not easy to monitor its condition in use. For equipment fabricated in small workshops or by the farmers themselves, it becomes very difficult to ensure that design standards are adhered to especially when the users of equipment are hired labourers on daily wages. This paper presents the results of an epidemiological study to determine the main causes of injuries among farmers in nine villages in the state of Haryana in Northern India. The study revealed that the largest number of traumatic injuries are caused by fodder cutting machines and threshers. The designs of these machines have been made safer using ergonomics principles. A large number of minor injuries are caused by hand tools.

TWO-WHEELER INJURIES IN DELHI, INDIA: A STUDY OF CRASH VICTIMS HOSPITALIZED IN A NEURO SURGERY WARD

The motorized two-wheeler population has increased in Delhi by more than 300% in the last decade. Bicyclists and motorcyclists accounted for 244 traffic accident deaths in Delhi in 1980. The present study was undertaken to determine the head injury patterns of two-wheeler riders admitted to a hospital in Delhi. A total of 87 crash victims were studied over a period of one year. The results indicate that collision patterns, age distribution, average injury severity and driving experience of patients admitted were different from those reported in studies conducted in industrialized countries. A vast majority of the injuries were in temporal, parietal and facial areas. Injury data indicate that helmets when used are effective in preventing or ameliorating head injury.

Road Traffic Injuries: A Stocktaking

Once we accept that road traffic injury control is a public health problem, and that we have an ethical responsibility to arrange for the safety of individuals, then it follows that health and medical professionals have to assume responsibility for participating in efforts to control this pandemic. Over 1.2 million people die of road traffic crashes annually. Road traffic injuries are among the second to the sixth leading causes of death in the age groups 15-60 years in all countries around the world. Control of road traffic injuries is going to require very special efforts as patterns are different in high- and lower-income countries, and while some countermeasures are applicable internationally, others will need further research and innovation. We will need to focus on the safety of pedestrians, bicyclists and motorcyclists, speed control, and prevention of driving under the influence of alcohol.

Traffic safety and city structure: lessons for the future

OBJECTIVE To understand the critical factors that are likely to influence road traffic fatality rates in large cities around the world in the next few decades. MATERIAL AND METHODS Road traffic fatality data for 56 cities around the world and for cities with a population of greater than 100,000 in the USA were collected and analysed to understand factors affecting differences in fatality rates. RESULTS There are wide variations in fatality rates across income levels and within similar incomes levels. The risk varies by a factor of about 20 between the best and the worst cities. CONCLUSIONS These patterns appear to indicate that it is not enough to have the safest vehicle and road technology to ensure low road traffic fatality rates. City structure, modal share split, and exposure of motorists and pedestrians may have a significant role in determining fatality rates, in addition to enforcement, vehicle crashworthiness and road design.