Adelaide in-depth accident study 1975-1979. Part 2: Pedestrian accidents

This report contains descriptions of the causes and consequences of the pedestrian accidents contained in a representative sample of road traffic accidents to which an ambulance was called in metropolitan Adelaide. Reviews of the relevant characteristics of the pedestrians and drivers, the vehicles, and the road and traffic environment are also included. All but one of these 40 accidents occurred on busy roads. Some measures designed to increase the rate of flow of vehicular traffic are detrimental to the safety of the pedestrian, to the extent that some urban arterial roads are very hazardous for some pedestrians, particularly children and the elderly. The pedestrian was more likely to have been careless, or to have made a mistake, than was the driver, but alcohol intoxication was less apparent as a causal factor in these pedestrian accidents than in other types of accidents covered by this survey. The injuries sustained by the pedestrians were much more likely to be dangerous to life than were the injuries sustained by other road users involved in other types of accident. The front of the striking car, including the upper surface of the bonnet, accounted for more than half of the injuries. A number of possible countermeasures and topics worthy of further investigation are listed at the end of the report.A.J. McLean, N.D.Brewer, B.L. Sando

An intelligent pedestrian device: social, psychological and other issues of feasibility

An Intelligent Pedestrian Device (IPD) is a new concept in pedestrian safety. It is defined as a microprocessor based information device which detects the approach of oncoming vehicles and informs the pedestrian whether or not it is safe to cross. IPDs could be portable or fixed to a roadside station. They could help reduce pedestrian accidents, which cost £2681 million in the UK in 1994. This study aims to assess whether the concept is socially acceptable and what the design criteria might be. A study of social acceptance involved group interviews of 5-10 participants with 84 pedestrians in five categories: adults aged 18-60, elderly aged 65+, visually restricted, parents of children aged 5-9 and children aged 10-14. The results suggest that vulnerable pedestrians are more positive about the device than the more able-bodied. Theories that may help explain this are discussed and it is concluded that, with education and marketing, the IPD could gain a degree of social acceptance. Observation of more than 900 pedestrian crossing movements at four different sites showed a range of behaviours, and that people often take risks in order to reduce delay. IPDs will require pedestrians to change some of their behaviours, especially those that are risky. Legal acceptance will demand high levels of costly product research and development, and a portable device will not be technologically feasible until well into the next century. However, the wider social benefits of IPDs may be worth the costs. An outline of design criteria for basic and sophisticated portable IPDs is given, and alternative functions are suggested. It is recommended that further work concentrate on developing software and hardware for fixed modes of IPD. It is concluded that, ultimately, acceptance will probably depend on whether Government decides that the IPD has a place in the road environment of the future

Simulation of Vehicle-Pedestrian Interaction

The literature on vehicle crash reconstruction provides a number of empirical or classical theoretical models for the distance pedestrians are thrown in impacts with various types of vehicles and impact speeds. The aim of this research was to compare the predictions offered by computer simulation to those obtained using the empirical and classical theoretical models traditionally utilised in vehicle-pedestrian accident reconstruction. Particular attention was paid to the pedestrian throw distance versus vehicle impact speed relationship and the determination of pedestrian injury patterns and associated severity. It was discovered that computer simulation offered improved pedestrian kinematic prediction in comparison to traditional vehicle-pedestrian accident reconstruction techniques. The superior kinematic prediction was found to result in a more reliable pedestrian throw distance versus vehicle impact speed relationship, particularly in regard to varying vehicle and pedestrian parameters such as shape, size and orientation. The pedestrian injury prediction capability of computer simulation was found to be very good for head and lower extremity injury determination. Such injury prediction capabilities were noted to be useful in providing additional correlation of vehicle impact speed predictions, whether these predictions were made using computer simulation, traditional vehicle-pedestrian accident reconstruction methods or a combination of both. A generalised approach to the use of computer simulation for the reconstruction of vehicle-pedestrian accidents was also offered. It is hoped that this approach is developed and improved by other researchers so that over time guidelines for a standardised approach to the simulation of vehicle-pedestrian accidents might evolve. Thoracic injury prediction, particularly for frontal impacts, was found to be less than ideal. It is suspected that the relatively poor thoracic biofidelity stems from the development of pedestrian mathematical models from occupant mathematical models, which were in turn developed from cadaver and dummy tests. It is hoped that future research will result in improved thoracic biofidelity in human mathematical models

Auto rickshaw impacts with pedestrians - A computational analysis of post-collision kinematics and injury mechanics

Motor vehicle-related pedestrian road traffic collisions are a major road safety challenge and a leading public health issue, since they are a primary cause of death and serious injury worldwide. In many developing countries, the auto-rickshaw–a three-wheeled vehicle with a canvas roof and side curtains – poses a significant risk to pedestrian safety due to the poor impact energy absorption of its structures and materials. This study presents a parametric and comparative analysis of auto-rickshaw-related pedestrian impacts and pedestrian-ground impacts by computational simulation, using a Finite Element model of an auto-rickshaw and LS-DYNA, 50th percentile adult male and six-year-old child Hybrid III Anthropometric Test Devices (dummies). The comparative study explored the kinematic responses and injury metrics associated with both adults and children impacted by an auto-rickshaw, as well as the most commonly impacted areas of an auto-rickshaw and the injury metrics for the adult pedestrian produced by primary and secondary impacts. The output data of the impact simulation was correlated against reported injury metrics, Head Injury Criterion, Neck Injury Criterion, Combined Thoracic Index, Injury Abbreviated Injury Scale and reported risk level. The results suggest that adult pedestrians are subjected to a relatively high risk of head, neck and chest injuries during primary impacts at 10, 20 and 35km/h, respectively, and some of the impact simulations suggest a risk of fatality. The 6YO-child pedestrians are at risk of serious head and neck injury at 10 and 15km/h, respectively. During secondary impacts, defined as impacts with a floor surface, head and neck injuries produced from ground contact are significant, including fatal injury, at 10km/h and greater, while insignificant chest injuries were observed at 40km/h. Vehicle impact response was investigated and Aluminium-6016-T4 and magnesium-AZ31B windscreen frame materials and a polycarbonate windscreen were found to produce the lowest injury risk of all the materials investigated whilst offering the greatest safety at the lowest cost. The present study provides valuable evidence for informing a series of recommendations and guidelines to make the auto-rickshaw safer during impacts with pedestrians. Overall, it has found that impact velocity, vehicle contact region, impact position and pedestrian size significantly influence the post-kinematic response of a pedestrian impacted by an auto-rickshaw and injury risk during primary and secondary impacts. Moreover, child pedestrians are subject to a relatively higher risk, compared to adults, during primary impacts. Secondary impacts were associated with a greater risk of head and neck injuries compared to primary impacts, even at low-impact velocities. Secondary impacts, however, produced much lower chest injury risk compared to primary impacts. Thus, even at relatively low impact velocities, the auto-rickshaw cannot be considered a ‘pedestrian friendly’ vehicle for use in urban areas. iii A b s t r a c t Future suggestions to reduce the injury risk level and increase the safety of the auto-rickshaw should be the implementation of strict safety regulations and, or, consideration of engineering solutions, such as retrofitting injury mitigation technologies to those auto-rickshaw contact regions which pose the greatest risk of producing pedestrian injury. In addition, modification of the frontal end geometry of the vehicle is recommended to ensure that injury risk is minimised during primary and secondary impacts

The Tiger Vol. 101 Issue 9 2007-04-06

https://tigerprints.clemson.edu/tiger_newspaper/2440/thumbnail.jp