Browse Topic: Crash statistics
Single motorcycle accidents are common in Nagano Prefecture where is mountainous areas in Japan. In a previous study, analysis of traffic accident statistics data suggested that the fatality and serious injury rates for uphill right curves and downhill left curves are high, however the true causes of these accidents remain unclear. In this study, a motorcycle simulator was used to evaluate the driving characteristics due to these road alignments. Evaluation courses based on combinations of uphill/downhill slopes and left/right curves were created, and experiments were conducted. The subjects of the study were expert riders and novice riders. The results showed that right curves are even more difficult to see near the entrance of the curve when accompanied by an uphill slope, making it easier to delay recognition and judgment of the curve. Expert riders recognized curves faster than novice riders. Additionally, expert riders take a large lean of the vehicle body, actively attempted to ride on the inside corner, while that of novice riders was less. On the other hand, for downhill left curves, there was a tendency for delayed judgment of sharp curves, and riders were more likely to increase their speed. Also, the expert riders recognized curve curvature earlier and had a greater lean angle of the vehicle body than the novice riders, but there was no significant difference. From these results, the road alignment combination of uphill/downhill slopes and left/right curve has a significant impact on the risk of motorcycle accidents.
The National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) contains an abundance of field crash data. As technology advances and the database continues to grow over the years, the statistical significance of the data increases and trends can be observed. The purpose of this paper is to provide a broad-based, up-to-date, reference resource with respect to commonly sought-after crash statistics. Charts include up-to-date crash distributions by Delta-V and impact direction with corresponding injury severity rates. Rollover data is also analyzed, as well as historical trends for injury severity, belt usage, air bag availability, and the availability of vehicle safety technology.
Accident statistics have shown that older and obese occupants are less adaptable to existing vehicle occupant restraint systems than ordinary middle-aged male occupants, and tend to have higher injury risk in vehicle crashes. However, the current research on injury mechanism of aging and obese occupants in vehicle frontal impacts is scarce. This paper focuses on the optimization design method of occupant restraint system parameters for specific body type characteristics. Three parameters, namely the force limit value of the force limiter in the seat belt, pretensioner preload of the seat belt and the proportionality coefficient of mass flow rate of the inflator were used for optimization. The objective was to minimize the injury risk probability subjected to constraints of occupant injury indicator values for various body regions as specified in US-NCAP frontal impact tests requirements. The approximate model was established and the optimal combination of parameters was selected by NSGA-II genetic algorithm. The optimization results were verified via the finite element simulation model, showing that when the key parameters of the occupant restraint system were optimized, the joint injury risk probabilities of the senior women with a BMI of 24.5, 33.4 and 36.3 were reduced by 7.73%, 7.45%, and 9.48 %, respectively.
This paper examines the trends in rotorcraft accident statistics, particularly regarding Loss of Control In-flight accidents (LOC-I), with the aim of stimulating interest in new research relevant to this area. Despite recent safety initiatives, LOC-I rotorcraft accidents have been identified as a significant and growing contribution to accident rates. The fixed-wing commercial airline community faced a similar situation starting in the late 1990s and, through a coordinated international effort, developed a new training program to help reduce accident rates. Lessons learned from the fixed-wing work are presented to highlight the need for improved rotorcraft modeling tools to reduce rotorcraft accidents through higher-quality, simulator-based training programs. The findings from previous and ongoing rotorcraft modeling and simulation research are presented, and areas for further research are identified. A proposal is made in the paper for a workshop to bring together the key rotorcraft stakeholders to develop future steps in tackling rotorcraft LOC-I accidents.
Road accident between pedestrian and motor vehicle causes severe injuries and even death of pedestrian. The accident statistics show that the possibility of injury to pedestrian is higher in case of collision with car on busy roads. In car and pedestrian collisions, the pedestrian’s head hits with car bonnet and suffer from multiple injuries such as skull fractures and brain injury. The role of car bonnet structural strength plays an important role in pedestrian head injury level. To provide enough structural strength the high bonnet thickness is provided with under bonnet stiffeners, however thick bonnet and stiffeners reduces deformation of the bonnet during collision and increases injury level to pedestrian. Hence optimum bonnet thickness, least number and geometry of stiffeners and enough structural strength is important for bonnet to reduce injury level. The aim of this study is to analyse the effect of car bonnet thickness, number and arrangement of under bonnet stiffeners on head injury levels with the help of head injury criteria (HIC). Head Injury Criteria (HIC) is a measure of the likelihood of head injury arising from an impact during a car crash. It indicatesthe level of injury caused during a particular crash. A typical modern car bonnet is selected for investigation with variety of bonnet material thickness and different configurations of under bonnet stiffeners and head injury criteria (HIC) is computed with the help of computer modelling. Further, head linear velocity, acceleration and head injury risk are predicted for probability of skull fracture. The geometry of bonnet is optimized with the help of optimization technique and optimized bonnet geometry is validated experimentally by designing a bonnet test facility and head form imparter.
Transportation surveys illustrate that one of the most significant deterrents to bicycles as a form of conveyance is the concern with safety. Moreover, crash statistics also indicate that motor vehicles pose a severe risk to bicycles. As a result, this paper focuses on the development of a bicycle-mounted traffic monitoring system with the potential of providing early crash warnings to bicyclists. The system designed has a low monetary cost ($280.84) and is small enough to mount on a bicycle (94 mm × 56 mm × 89 mm). Moreover, it has sufficient range to track cars before they get dangerously close to the bike. The foundation of the system includes a Light Detection and Ranging (LIDAR) module that includes direct compatibility with microcontrollers. This LIDAR module interacts with a camera, stepper motor, and small computers through interfacing hardware and software. While robust, one limitation of the system is processing power. Specifically, its ability to detect cars is contingent on the performance of the computer that processes a video stream from the camera. With increased computing power, the system is capable of detecting lanes aiding in the search for cars, subsequently eliminating most false positives. Hence, augmenting processing capabilities of the current system would allow the vehicle recognition software to be more sensitive, ensuring that an automobile on the road is always detected.
The official Indian accident statistics show that the number of road accidents and fatalities are one of the highest worldwide. These official statistics provide important facts about the current accident situation. It is suspected that for various reasons not all accidents are reported to the official statistic. This study estimates the degree of underreporting of traffic accidents with casualties in India. In order to get a national overview of the traffic accident situation it is necessary to improve the knowledge about underreported accidents. Therefore, the in-depth accident database of “Road Accident Sampling System India” (RASSI) was analyzed [1]. This project is organized by a consortium that has collected traffic accidents scientifically in four different regions since 2011 on the spot which have been reported either by police or by local hospitals and own patrol by RASSI engineers. Thus, the level of underreporting is researched by comparing data from hospital records and police records in order to estimate the number of accidents which are not documented in official statistics. Based on a number of around 1 635 accidents mainly in rural area it was found that 32% of all documented cases are not recorded by the national police. Based on these findings it is assumed that the national statistics cover only about two-third of all rural crashes in India. Various characteristics of accidents can influence the percentage of underreported cases. Accident scenarios - e.g. classified by Accident Type - have different shares of underreported cases. RASSI data shows that every 2nd single vehicle accident (including pedestrian cases) is not notified in the official statistics. In the study the accident data is analyzed in detail concerning: Accident scenarios Road user category Injury severity Road conditions Infrastructural details Result of this study is an overview of the accident situation in rural area and point out the frequency of underreported accidents depending of typical accident characteristics. This information can be used to identify main causes of this phenomen.
Traffic injuries are an important public health issue. To prevent these injuries, safety systems in a vehicle are recognized as valuable tools. These safety systems are active before and during a crash event. Passive safety is one such safety tool which comprises of occupant restraint systems to prevent fatal injuries during an event of a crash. To improve the real life safety further, active safety systems plays an important role in mitigating the real world accidents. Moreover, effective integration of active and passive safety systems has a potential to further reduce car occupant fatalities. However, in the recent developments in India towards road safety, vehicle safety standards are oriented more towards passive safety. In the present work, road accidents data from India between 2005 and 2014 are studied, to estimate the major mode of accidents and factors influencing the fatal injuries. Technological and human factor interventions are derived from these accidents statistics. The data collected can be an important input in developing the active safety systems representing the real world scenario. The human errors and injury severities associated with above accidents, emphasize the need of both active and passive safety systems in a vehicle to avoid accidents and mitigate injuries. This paper signifies the need of a robust regulatory system combining both active and passive safety systems to reduce the proportion of road accidents and the fatalities.
Automotive OEMs, insurance agencies and regulatory bodies are continuously looking at various accident statistics and proper ways of evaluating unaccounted (as per current regulations and safety ratings) accident scenarios to improve the safety standards of cars. Small overlap and oblique impacts during which a corner of a car hits a tree or the corner of another vehicle are two such situations. Most of the vehicles that are on road scored low when tested for these impact scenarios. This paper focuses on development of energy-absorbing members, using engineering thermoplastics materials, which can be mounted on the BIW of a vehicle, as countermeasures to small overlap impact. Various design and material configurations options, including metal plastic and composite plastic structural members mounted on the BIW are evaluated through CAE studies, against small overlap/oblique impact scenarios. Different approaches of impact energy absorption and energy transfer have been studied to improve crashworthiness of vehicle. Vehicles with and without these structural members are evaluated for small overlap impact using CAE tools like Ls-Dyna. It is observed that vehicles mounted with these additional structural members perform significantly better in small overlap impact (SOI) scenarios than vehicles without these members.
Japanese accident statistics show that despite the decreasing trend of the overall traffic fatalities, more than 1,000 pedestrians are still killed annually in Japan. One way to develop further understanding of real-world pedestrian accidents is to reconstruct a variety of accident scenarios dynamically using computational models. Some of the past studies done by the authors' group have used a simplified vehicle model to investigate pedestrian lower limb injuries. However, loadings to the upper body also need to be reproduced to predict damage to the full body of a pedestrian. As a step toward this goal, this study aimed to develop a simplified vehicle model capable of reproducing pedestrian full-body kinematics and pelvis and lower limb injury measures. The simplified vehicle model was comprised of four parts: windshield, hood, bumper and lower part of the bumper. Several different models were developed using different combinations of geometric and stiffness representation. A unique model called a multi-layer model developed in this study represented each of the hood and the windshield with a stack of the panel representing the entire area of these components, while applying localized stiffness characteristics and contact definition with a particular pedestrian body region that contacts with the layer represented by the stiffness characteristics. These models were made to collide with the human FE model, and pelvis and lower limb injury measures and full-body kinematics were compared with those from the simplified vehicle models. The results of the comparisons showed that the multi-layer model provided a more realistic contact interaction between the pedestrian body and the vehicle by eliminating the gap between adjacent panels due to geometric division of a large vehicle body panel.
It is known that the collisions caused by lane departure events account for range of percentages among the countries studied. To help prevent such collisions, the Lane Departure Warning (LDW) system has started to be introduced in production vehicles, but there is little research on its benefits and limitations so far. In this paper we performed an in-depth analysis of the collisions and driver-related essential variables for the lane-departure collision scenarios and demonstrated the benefit estimation process. The benefit of the LDW system is estimated by comparing lane departure events when the vehicle has no LDW, and how they change with the addition of LDW. The event without LDW was modeled in 5 phases: (1) before departure, (2) starting of the departure, (3) departed the lane, (4) at the impact with an object, and, (5) after the impact. “An extensive analysis was conducted of traffic crash data compiled by the Institute for Traffic Accident Research and Data Analysis (ITARDA). The results of this analysis were used to create models of each phase of an LDW event. The Advanced Safety System & Traffic REaltime Evaluation Tool (ASSTREET), which is based on Monte-Carlo Simulation, was then used to simulate a variety of collision types. The results of these simulations were validated by comparing the distributions of fatality, serious injury, minor injury and no injury that they generated to crash statistics for Japan. Then, the effect of the LDW system was added to the lane departure events. The drivers' response delay to the LDW and the possible reactions were measured in a driving simulator test. The comparison between events with and without LDW clearly shows which cases could be prevented by the use of LDW and the ones that could not be avoided, thereby, providing us with important guidelines to improve the system performance.
In Japan, the number of occupant fatalities has decreased at high ratio due to the development of passive and active safety technology in recent years. However, the pedestrian fatality is still the major proportion of fatalities according to the statistics of traffic accident. Therefore, it is important to study and develop active safety technologies which target to pedestrian. By analyzing the traffic accident statistics, narrow road in urban area is one of the dangerous parts for pedestrian. And the dangerous case that pedestrian often gets into an accident is while crossing road outside of crosswalk. This study focuses on accidents which are caused by pedestrians suddenly crossing narrow urban roads. In such cases, drivers need to drive carefully, preparing for sudden crossing or unexpected dangerous behavior of pedestrians. Therefore, it is important for drivers to predict the accident risk due to the crossing pedestrian behavior in such narrow roads. The final goal of this study is to find out the hazard anticipation mechanism in such scenes and to design a driving assistance system, such as, a warning or intervention system. To design such a driving assistance system it is necessary to describe a model of sudden crossing or unexpected dangerous behavior of pedestrian. To describe pedestrian behavior in urban area, near-miss incident database is analyzed which has been developed by JSAE. This database includes all kind of incidents collected by drive recorder, or black box, attached to Taxis in down town Tokyo. By using the database, we constructed a mathematical model for quantifying pedestrian behavior from camera image data, and verified the validity of the method by computer simulation.
Accident statistics shows pedestrian accident fatalities as one of the important concerns globally. In view of this, new test protocols for pedestrian safety have been drafted in regulation as well as in consumer group. Also as per new ENCAP requirements, pedestrian safety assessment is used as one of the four assessment criteria's (Adult protection, child safety, pedestrian safety, safety assist) in deciding the overall vehicle safety. Hence today importance of pedestrian safety is perceived as never before in vehicle development program. Basically pedestrian safety evaluation involves subsystem level (head form, upper leg form and lower leg form) impact tests representing human body parts, at specific region on test vehicle with injury limits to decide the severity of impact. In general these injuries are governed by vehicle styling, vehicle stiffness, hard points clearances from vehicle exterior like bonnet, bumper etc. For head impact, design parameter that mainly control the injury, like bonnet top stiffness design and under bonnet clearances remain valid for both passenger cars as well as for SUV's (Sport Utility Vehicles). Upper leg from impact test is not mandatory to be met in regulation and also difficult to meet in SUV class type vehicles as the location of impact is guided by bonnet leading edge which are quite high in case of SUV's because of vehicle stance. In case of lower leg test, injuries are mainly guided by front styling and bumper to hard point clearance. In SUV's as compared to passenger cars as the ground clearance from the ground is generally higher and vehicle styling is aggressive, controlling the injuries within the limits are quite challenging. This paper specifically discusses important design aspects on controlling the injuries of lower leg form for a SUV type vehicle to meet target requirements. This paper attempt to demonstrate the importance of vehicle front end styling, bumper system design, location of energy absorber, bumper profile, front end stiffness and limitation of bumper to hard point clearance in meeting the lower leg injuries.
Plug-in electric vehicles are becoming increasingly popular as the U.S. and other nations look for ways to reduce the usage of petroleum fuels and reduce the carbon emission footprint. Though plug-in electric vehicles offer many advantages over conventional vehicles, they also present some unique potential hazards due to the presence of high voltage in the vehicle. Specifically, potential high voltage hazards can occur if the electric vehicle is crashed by another vehicle during its plug-in charging session. High voltage hazards include the possibility of electrical shock and thermal events as a result of electrical arcing that can cause injury or death to persons that operate or work around plug-in electric vehicles. Automotive Safety Integrity Level (ISO 26262), often abbreviated as ASIL, is used by the automotive industry for determining the ranking of safety hazards. The likelihood of exposure to a particular safety hazard that leads to a mishap is one of the factors used for ASIL rankings. Thus, it is necessary to understand the likelihood of a crash during a plug-in charging session in order to evaluate the ASIL ranking for hazards due to this particular scenario. This paper will analyze crash statistics in the United States and other factors to determine the likelihood of high voltage exposure due to a crash during a plug-in charging session.
Developments in avionics, communications, and air-traffic management enable more affordable and better ways to fly and navigate. The tragic crash of the Polish-government-operated Tupolev Tu-154 on April 10, which came down after hitting trees on its approach to the airport runway at Smolensk, Russia, killed not only that nation's President and First Lady but also scores of Poland's military and civilian elite, including military and business leaders, ministers, and representatives of organizations ranging from war veterans to officials from the church and charities. National implications of this high-profile flying disaster can be imagined, but sadly, aircraft crashes on approach in poor weather, often involving small regional or general aviation aircraft, or business jets, are not yet a thing of the past.
The National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) contains a wealth of field accident data. As the size of the database continues to grow, the statistical significance of the data increases and trends can be observed. Numerous papers contain analysis and graphs of particular aspects of the data, but they are usually included in a supporting role to the main topic of the paper, and are extremely difficult to locate in a focused document search. The purpose of this paper is to provide an updated, comprehensive resource to reference when looking for commonly sought-after accident statistics. Charts include accident distributions by Delta-V and impact direction with corresponding injury severity rates. Rollover data is also analyzed, as well as historical trends for injury severity, belt usage, and air bag availability.
For occupant protection in vehicle crash, several kinds of ATDs (Anthropomorphic Test Devices) and associated injury criteria have been used to evaluate the performance of a vehicle body, restraint systems and other safety devices. Because of the lack of sufficiently validated injury criteria for the lumbar spine, it has been a concern that the effectiveness of some safety features for injury reduction based on the dummy and associated injury criteria may not be reasonably assessed. Therefore, in this study, a human FE model capable of evaluating lumbar spine skeletal injuries was developed. Considering an increasing percentage of the traffic accidents relating to elderly people due to extending span of human life and decreasing birthrate, not only an adult model but also a model that represents lowered tolerance of the elderly was developed. From traffic accident statistics, 35 and 75 years old (y.o.) were defined as the representative ages of adult and elderly populations. An existing human FE model for an adult male was adopted for the baseline. The material properties of the trabecular bone of the lumbar vertebra for 35 and 75 y.o. were determined using the compression characteristics from the literature. Because of the lack of published data, those of the cortical bone were estimated so that the maximum (fracture) forces of the whole vertebrae under static compression predicted by the models agree to those of the tests from the literature. The isolated vertebra FE models were validated against dynamic compression and endplate impact tests for respective generations from the literature, and the result showed good agreement in maximum (fracture) forces. Then the whole lumbar spine model was validated against dynamic flexion, extension and lateral bending tests from the literature for the overall kinematics.
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