Severity of vehicle bumper location in vehicle-to-pedestrian impact accidents

Pedestrian protection is one of the key topics for safety measures in traffic accidents all over the world. To analyze the relation between the collision site of the vehicle bumper and the severity of the lower extremity injuries, we performed biomechanical experiments. We compared the applied external force and the risks of subsequent injuries between the impact of the center and side positions of the front bumper. These comparisons were performed by practical impact tests with eight typical different types of cars which were typical of the current vehicle fleets. The tests were made using the TRL legform impactor which was a mechanical substitute of a pedestrian lower extremity. The TRL impactor is used all over the world for assessing the safety of car bumpers. It was found that the risks of lower extremity injuries in the impacts at the side positions, in front of the vehicle's side member, were significantly higher than those at the center. In the tests, we found that foam materials around the rigid front cross member had a significant effect on reducing the lower extremity injury risks and especially tibia fracture risk against vehicle bumper center collisions, but had little effect at the sides of the bumper over the vehicle's side members where the foam was thinner. We also found that the front shape of the vehicle affected the risk of ligaments injuries. According to these results, the information of impact locations of cars in vehicle-to-pedestrian traffic accidents is valuable for clinicians to diagnose patients with lower extremity injuries in traffic accidents and for forensic pathologists to analyze the accident reconstruction. Furthermore, the results suggest that testing of the bumper area in front of the main longitudinal beams should be included in the car safety legislation to require pedestrian safety.     

交通事故中车辆安全技术状况检验及典型案例车速计算

目的 针对导致交通事故的各种原因就车辆因素进行了较详细的分析.方法 对进行车辆技术状况检验的着手方面、要点做了相关分析并结合相关实例进行举例分析,对造成事故中的关键因素车速的计算及计算方法做了简要讨论.结果 总结了进行整车配置、制动系统、转向系统、汽车灯光与信号系统与轮胎检验时需注意的要点.根据车速计算方法,得出一起追尾事故中某货车在事发时未达到高速公路最低限速的鉴定结论.结论 进行车辆安全技术状况检验时,需注意相关要点,以尽量避免道路交通事故的发生.     

Computer simulation of the accident with nine victims

In the paper we wish to emphasise the significance of vehicle driving dynamics analysis in the collision phase and occupant load analysis by means of using a software environment. Thereby we also wish to present the results of the simulation of the course of a traffic accident with nine victims that arose from a collision between an Audi A6 passenger car and the VW Caravelle van. In treating the traffic accident the forensic expert was faced with the questions about what caused the injuries to the front passenger in the Audi A6 passenger car, about the way the two vehicles had collided, about their collision velocities, about the way the two vehicles were handled and about the causes that originated the traffic accident. The critical situation on the road was a consequence of the tiredness of the van driver, the inadequate use of the passive safety systems and overloading the van.     

路试充分发出平均减速度可取信范围分析

当我们使用便携式制动性能测试仪来检验涉案车辆制动性能,为什么有时获得的充分发出的平均减速度（MFDD,mean fully developed deceleration）值会大于重力加速度g,这些较大的MFDD值与《便携式制动性能测试仪校准规范》中的测量范围是否相冲突,这些检测值在车速等运算中是否可以被采信,路试检验MFDD的有效范围是什么,鉴定业界对这些问题有着诸多争议和不同答案。本文旨在对路面摩擦系数进行讨论,并利用达朗贝尔原理建立车辆制动受力模型,从而证明高于g的充分发出的平均减速度在路试检验中可以成立,并确认了该值的可以取信范围0~l1h×g。     

Pedestrian accident analysis with a silicone dummy block

When a car is parked in an inclined plane in a parking lot, the car can roll down the slope and cause a pedestrian accident, even when the angle of inclination is small. A rolling car on a gentle slope seems to be easily halted by human power to prevent damage to the car or a possible accident. However, even if the car rolls down very slowly, it can cause severe injuries to a pedestrian, especially when the pedestrian cannot avoid the rolling car. In an accident case that happened in our province, a pedestrian was injured by a rolling car, which had been parked on a slope the night before. The accident occurred in the parking lot of an apartment complex. The parking lot seemed almost flat with the naked eye. We conducted a rolling test with the accident vehicle at the site. The car was made to roll down the slope by purely gravitational pull and was made to collide with the silicone block leaning against the retaining wall. Silicone has characteristics similar to those of a human body, especially with respect to stiffness. In the experiment, we measured the shock power quantitatively. The results showed that a rolling car could severely damage the chest of a pedestrian, even if it moved very slowly.     

论自动驾驶汽车生产者的刑事责任

自动驾驶汽车是人类研发、制造、使用和管理的智能产品,不是犯罪主体或刑事责任主体。在自动驾驶汽车自主控制状态下发生交通事故的,其生产者、使用者和其他人员难以按照我国现有刑法的罪名定罪处罚。除非道路交通安全法和刑法有专门的规定,驾驶位人员不接管汽车或接管后无力改变交通事故结果的,不构成交通肇事罪或其他管理过失犯罪。驾驶位人员的注意义务是阻止自动驾驶汽车自主控制下发生交通事故,其注意义务不应过高。允许的风险、紧急避险理论不能为自动驾驶汽车紧急路况处理算法的生产与应用提供合法、合理的解决方案,生产者遵守算法安全标准仅可以使生产行为合法化。鉴于现行刑法不适应自动驾驶汽车应用的特性,我国应当建立以生产者全程负责为中心的新刑事责任体系,使之在自动驾驶汽车生产和应用两个阶段承担安全管理责任,生产者拒不履行自动驾驶汽车应用安全管理义务且情节严重的,应当承担刑事责任。     

Decapitation in road traffic accident--a case report

A 20-year-old girl along with four of her friends, all in their early 20s, met with a fatal accident in the early hours of the day. Their car was hit by a speeding truck at a crossing. All the occupants of the car sustained multiple injuries and died on the spot. The girl was decapitated in the accident. Her head was recovered outside the mangled remains of the vehicle and the rest of the body was extracted from the co-driver's seat of the damaged vehicle.     

Murder and robbery by vehicular impact: true vehicular homicide

True vehicular homicides are defined as those occurrences in which a motor vehicle is intentionally used as a weapon in taking of a life. A case is presented in which the deceased was traveling in the front passenger seat of a motor car that was deliberately rammed by a heavy jeep that came in the opposite direction, resulting in a serious frontal collision. Immediately after the impact, while the occupants of the car were lying in a dazed condition, the two persons riding in the jeep escaped with a bag containing money that was in the car, leaving the jeep behind. The impact mainly involved the driver's sides of both vehicles. The driver of the car sustained serious injuries but was found to be alive, whereas the front-seat passenger, who did not show any serious external injuries, was found to be in a collapsed state and was pronounced dead on admission to the hospital within 30 minutes of the accident. The autopsy revealed that death was caused by closed hemopericardium from a ruptured right atrium. The evaluation of the external and internal injuries confirmed that the fatal injury and a few serious internal injuries were caused by the seat belt (tertiary-impact injuries). The ruptured right atrium was attributed to blunt abdominal trauma by impacting against the lap belt. The case was a true vehicular homicide in which a motor vehicle had been used as a weapon to kill a person. Various aspects pertaining to road accidents, the safety of the occupants, and the advantage and disadvantage of the safety devices are discussed.     

Motor vehicle accident with complete loss of consciousness due to vasovagal syncope

Vasovagal syncope (VVS) is one of the most common causes of complete or partial loss of consciousness, thus it might cause harm to the patients themselves or innocent bystanders while driving a car. In our case report we introduce the case of a 60-year-old man who was admitted to hospital after a serious motor vehicle accident due to loss of consciousness. We demonstrate the process and results of complete cardiologic and neurological assessment. Our case report illustrates the importance of recognition of patients with a high risk for incapacitating symptoms due to VVS, and the use of head-up tilt-table tests to determine the diagnosis and to guide therapy with beta-blocking agents. As transient loss of consciousness during driving may cause potentially fatal accident, it has to be taken into consideration during decision making for issue of driving licenses to patients with VVS.     

关于利用制动痕迹长度估算车速问题探讨

目的采用理论、实验和实际案例相结合的方法,探讨＂利用制动痕迹长度估算制动速度＂的应用问题。方法通过20辆小型乘用车紧急制动实验,对制动距离、制动力上升时间、制动纵滑附着系数等数据进行分析。结果得出制动车速与估算车速有的差异比较大,有的差异比较小,分析了产生差异的原因。结论如果计算参数选取不当,利用制动痕迹长度估算制动速度的方法有很大的局限性。     

Motor vehicle accident with complete loss of consciousness due to vasovagal syncope

Vasovagal syncope (VVS) is one of the most common causes of complete or partial loss of consciousness, thus it might cause harm to the patients themselves or innocent bystanders while driving a car. In our case report we introduce the case of a 60-year-old man who was admitted to hospital after a serious motor vehicle accident due to loss of consciousness. We demonstrate the process and results of complete cardiologic and neurological assessment. Our case report illustrates the importance of recognition of patients with a high risk for incapacitating symptoms due to VVS, and the use of head-up tilt-table tests to determine the diagnosis and to guide therapy with beta-blocking agents. As transient loss of consciousness during driving may cause potentially fatal accident, it has to be taken into consideration during decision making for issue of driving licenses to patients with VVS.     

Two Simple Formulas for Evaluating the Lower Bound of the Impact Velocity in Vehicle–pedestrian Accidents

Formulas for evaluating the lower bound of the impact velocity are valuable in vehicle–pedestrian accident reconstruction. The theory of classical mechanics and four hypotheses were employed to derive formulas; the research results and simulation/accident tests were employed to validate their feasibility. Then, two simple formulas were developed according to the distance between the rest positions of the vehicle and the pedestrian and the flight‐phase distance. The results showed that the evaluated results by the two proposed formulas are inferior to the existing results. The influence of a roadside step on the impact velocity, which decreased with an increase in the flight‐phase distance and a reduction in the road slope, was evaluated. Based on a real accident, the study concludes that the lower bound can be easily obtained with the proposed formulas, which can be used to determine the evaluated impact velocity during simulations.     

Massive lesions owing to motorcyclist impact against guardrail posts: analysis of two cases and safety considerations

Two motorcycle riders lost control of their vehicle, fell, and hit a guardrail, which acted as a blade and led to a rapid, fatal outcome. In one case, the high velocity of the body at the time of the impact resulted in complete detachment of the trunk. Reconstruction of the accident dynamics enabled the guardrail post to be identified as the means of injury in both cases. The two accidents occurred over a short period of time, highlighting a dangerous phenomenon that in less severe cases is presumably associated with different degrees of survivor disability. The accidents deserve mention, because a different design of the impact surface of the guardrail post might have prevented the lethal outcome. There is an urgent need for legislators to pass regulations that modify crash barrier homologation criteria, which have been devised primarily for the safety of car passengers but fail to protect motorcyclists.     

通过痕迹认定肇事车辆

随着交通事故勘验技术的发展,物证技术在重特大交通事故现场勘验以及侦破交通逃逸案件中发挥的作用越来越重要.痕迹检验技术作为物证技术的一个重要分支,在认定肇事车辆中发挥着举足轻重的作用.交通事故中的痕迹是车辆与车辆、人体、道路等客体在路面上相对高速运动形成的痕迹,相对于其它类型案件有着自己的特点.交通事故中的痕迹分布范围广、造痕体和承痕体相对运动剧烈,形成痕迹的造痕体和承痕体大多都会发生形变.基于交通事故中痕迹形成的这些特点,交通事故中的痕迹检验难度是比较大的.但交通事故中车辆的特殊结构形成的印压痕迹、车辆轮胎、摩托车车篮等造痕体在灰尘等介质作用下在人体的衣服等表面形成的印压痕迹都可以很好反映造痕体的外部结构特征,从这些痕迹反映出造痕体的外部结构特征可以寻找和认定交通肇事车辆.     

Motions of passenger cars in low-speed falls over embankments

An analysis of the dynamics of motions of passenger cars in falls over embankments at speeds less than that required to launch a car into a free-fall trajectory is developed in this paper as an aid in evaluating initial vehicle speed in this particular type of crash involved in the forensic science field of accident reconstruction.     

Determination of Vehicle Speed from Recorded Video Using Reverse Projection Photogrammetry and File Metadata

The prevalence of security and in‐car video has increased the number of motor vehicle accidents captured on digital video. However, inconsistencies in how to accurately determine time and distance for vehicle speed has led to examinations with varying results. A potential solution for calculating time intervals is to use frame timing contained within many digital video file's metadata, recorded with 0.000001 sec precision. This paper examines a fatal motor vehicle accident where frame timing information was used with distance measurements from reverse projection photogrammetry to calculate vehicle speed. A margin of error was then calculated based on the accuracy in performing reverse projection photogrammetry distance measurements. The resulting speed calculation was then compared to event data recorder data and found to be within an average of ±1.43538 MPH. Using specific time intervals may lead investigators to more accurate speed calculations, specifically those involving variable frame rate video.     

Influence of post mortem changes on experimental safety belt injuries

Belt protected car occupants involved on head-on collisions do not seem to suffer as severe injuries as unembalmed cadavers subjected to comparable simulated head-on collisions. Therefore it has been questioned if cadavers constitute adequate test specimens for study of thoracic tolerances. This investigation compares injuries in safety belt wearing living and dead pigs which have been subjected to simulated head-on collisions on an acceleration tract. Tests were performed on all 20 pigs (10 living and 10 dead). The arterial side of the circulatory system of the dead pigs was infused. The force in the safety belts, the intraaortic pressure, the impact velocity and the deceleration of the sled were recorded. The tests were high speed filmed. Post mortem examination of the pigs revealed differences in injury severity. Dead pigs more easily suffered rib fractures. Deformation of the rib cage due to stripping of the periosteum and laceration of surrounding tissue occurred mainly in the dead pigs. Laceration of intrathoracic blood vessels was seen in dead pigs while isolated heart lesions were seen only in living animals. The main cause of these differences in tolerance level seems to be post mortem changes of the mechanical properties of the different tissues. The results are valid for pigs but indicate that great care has to be exercised when results obtained from cadaver experiments are evaluated concerning thoracic tolerance.     

Identification of tiny and thin smears of automotive paint following a traffic accident

Three complementary methods in the order of stereomicroscopy, micro-FT-IR spectroscopy and solubility tests were used for the purpose of matching known and questioned paint samples in an auto accident case. Grayish green paint smears scattered on a silvery gray coated plastic bar were taken from a blue car and referred to as questioned samples. Green paint chips were collected as known samples from a green car. These were analyzed to determine whether the paint smears found in the blue car could have been the transfers from the green car. Although each of the three methods, when used alone, suffered from unequal bases for making comparison (i.e., layering whole paint vs. smeared paint), insufficient specificity of methodology and the interfering background coating beneath the smeared paint, the limitations were significantly relieved when three methods were used in combination. Based on the results presented in this report, the questioned grayish green paint smears collected from the blue car and the known green paint chips from the green car are of the same class of paint; that is, the possibility of the above stated paint transfers cannot be eliminated.     

The influence of vehicle model and colour on assessments of speed and culpability: the case for (and against) Computer Generated Exhibits (CGE)

Computer Generated Exhibits (CGE) are frequently deployed in legal contexts under the rubric of demonstrative evidence, i.e. to facilitate juror comprehension. However, a number of legal and academic commentators have suggested that the nature of the computerised moving image could exert undue prejudice on decision makers, e.g. judge and/or jury. The current study aimed to assess the manipulation of vehicle characteristics (make and colour) when a road traffic accident was presented in the format of a computer generated animation (CGA). In experiment 1, two groups of subjects watched two different makes of car, a Range Rover Sport and a Volkswagen Touran in a black-and-white format; no significant differences emerged over vehicle model with regards to vehicle speed or overall responsibility for the accident. Experiment 2 presented the same vehicles to four groups of participants in full colour, with the cars in contrasting red or beige; significant differences emerged with regards to culpability for vehicle make only. The findings could have implications for the format and style of CGE used in legal settings.     

Fabric evidence studies of seat belts

Investigations on safety belts give useful informations for the reconstruction of the sitting position of passengers of a car involved in an accident. Two examples from the practice show extraordinary trace combinations.