Browse Topic: Pedestrian injuries

Items (87)
Aims of the research This study aims to modify the lower body (the pelvis, thigh, and leg) of the mid-sized male pedestrian dummy FE model by considering the latest version of the physical dummy and to evaluate both the accuracy by comparing test results of the past studies and the biofidelity specified in SAE J2782 in both component and full-scale validations. Methods 1 Component validation The validation of the modified pelvis model was performed in dynamic lateral compression simulations. The sacrum and the pubis force-deflection responses of the iliac or the acetabulum impact were measured. The modified thigh and leg models were evaluated in a dynamic 3-point lateral bending simulation, measuring the force-deflection responses. The results from the simulations were compared with test results and the biofidelity requirements. 2 Full-scale validation The whole-body model was updated by incorporating these modified component models. The model of the generic buck developed for the assessment of pedestrian whole-body impact response and specified in SAE J3093 was used in this study. The buck model was made to collide with the full-scale dummy model at 40 km/h laterally. The trajectories of the head, upper spine, mid-thorax, and pelvis were measured and compared with those of the test results and the biofidelity requirements. Results The force-deflection responses from the pelvis, thigh, and leg models were similar to those of the test results, indicating they almost fell within the biofidelity requirements. As the results of the full-scale simulation, the trajectories of the head, upper spine, mid-thorax, and pelvis showed a strong agreement with those of the test results, indicating almost the same tendency as the biofidelity corridors, except for that of the pelvis. Conclusions As the results of component and full-scale validations, the equivalences of the modified pedestrian dummy model to test results and the biofidelity were confirmed in most cases.
Asanuma, HiroyukiGunji, YasuakiMori, FumieNagashima, Akiko
To reduce traffic fatalities through vehicle safety measures, particular attention must be given to cyclist-related fatalities. Clarifying the characteristics of hazardous events leading to cyclist fatalities, not only by vehicle speed range but also by vehicle type, is essential and should be based on analyses of real-world accident data. Accordingly, this study aimed to characterize fatal cyclist accidents involving vehicles traveling at low and high speeds in Japan. We used macro accident data from the Japanese Institute for Traffic Accident Research and Data Analysis covering the period from 2013 to 2022. Based on nine vehicle types, we investigated the effects of road type, vehicle behavior, and accident type on cyclist fatalities. Additionally, we identified the five most frequent accident scenarios separately for each low- and high-speed category. At signalized intersections, the proportions of cyclist fatalities involving vehicles traveling at low speeds were higher than those involving vehicles traveling at high speeds across all vehicle types. In contrast, on straight roads, the proportions at low speeds were lower than those at high speeds for all vehicle types. In the low-speed range, cyclist fatalities within the top five scenarios accounted for 65% of all fatalities, with the most frequent scenario occurring at signalized intersections during left-turn maneuvers, where heavy-duty trucks accounted for 86% of the fatalities. In the high-speed range, cyclist fatalities within the top five scenarios accounted for 71% of all fatalities. The most frequent high-speed scenario involved crossing collisions at unsignalized intersections when vehicles traveled straight, with light passenger cars and sedans accounting for 29% and 24% of the fatalities, respectively. These findings provide valuable insights for the development of targeted traffic safety regulations and vehicle technologies aimed at reducing vehicle–cyclist collisions across different speed ranges.
Matsui, YasuhiroOikawa, Shoko
Pedestrian fatalities in traffic accidents continue to rise, with severe injuries often resulting from both vehicle impact and subsequent ground contact, frequently occurring outside the field of view of vehicle-mounted cameras. This study presents a proof-of-concept (PoC) approach for reconstructing three-dimensional pedestrian motion—including occluded regions—using dashcam video. The method integrates 2D human pose estimation (MMPose) and monocular depth estimation (Depth Anything V2),the latter was fine-tuned on a custom dataset, to generate 3D skeletal coordinates.To evaluate motion matching, the reconstructed pedestrian poses were quantitatively compared with a database of vehicle collision simulations using the THUMS human body model and skeletal data representing real-world crash scenarios generated in PC-Crash. Composite similarity indices based on thoracic center of gravity trajectory and torso orientation vectors were employed for this comparison. Preliminary results indicate that the fine-tuned system achieves an average RMSE of approximately 0.1 m for key skeletal points, enabling accurate depth estimation for 3D pose reconstruction. Matching experiments with 11 PC-Crash cases demonstrated high similarity scores, and reconstructed sequences successfully identified critical injury events such as head-to-ground contact in occluded regions, confirming the feasibility of this approach for accident reconstruction and injury risk assessment. However, this study remains preliminary, limited to controlled indoor experiments with a single vehicle type and few subjects. Real-world crash footage and diverse vehicle geometries were not considered, and skeletal reconstruction from actual accident videos has not yet been implemented. Future work will expand the simulation dataset, refine similarity weighting, and validate the approach using real crash video. Ultimately, this technology may support forensic analysis and emergency response, but further validation is required before real-world application.
Onishi, KojiWang, KewangUno, ErikoIchikawa, KojiTanase, NoboruAndo, Takahiro
The proportion of pedestrian injuries in motor-vehicle-crash-induced injuries in the U.S. has been increasing in recent years. Although extensive police-reported data on pedestrian injuries is available, the incomplete nature of the crash and injury information in these datasets presents a significant challenge for statistical injury analysis and pedestrian protection research. This study aims to address this issue by combining simulation data and field data to impute critical missing crash information in pedestrian crash cases through machine learning techniques. A total of 9,000 MADYMO simulations were generated using maximal projection design, incorporating variables such as pedestrian demographics, crash conditions, and vehicle impact parameters. Gaussian process (GP) surrogate models were trained to predict injury risks with simulation parameters calibrated using the complete crash information in the Pedestrian Crash Data Study (PCDS) dataset. Maximum likelihood estimations were then employed to impute the missing vehicle speed in Linked Michigan Trauma dataset. Validation involved comparing the imputed vehicle speed distribution with that of the PCDS dataset and verifying four CIREN cases reconstructed by both the proposed method and a physics-based approach. The histogram of the reconstructed vehicle speeds in Linked Michigan Trauma dataset highly correlated with that from the PCDS dataset. In the four CIREN cases, the absolute deviation between the reconstruction vehicle speeds from the proposed method and physics-based approach was 9 kph on average, with the predicted injury risks matched the observed AIS levels. These results support the use of machine learning for reconstructing missing crash data and enhancing pedestrian injury risk modeling.
Song, XiaoyangSun, WenboHu, JingwenFlannagan, CarolKarlow, JaredBowman, PatrickFarooq, IskanderKalra, Anil
This study validates the use of the pedestrian multibody model in the simulation software PC-Crash. If reasonable inputs are used, the pedestrian model will yield accurate simulations of pedestrian collisions, particularly in terms of accurately simulating the contact points between the pedestrian and the vehicle and in predicting the throw distance of the pedestrian. This study extends prior studies of the PC-Crash pedestrian multibody model by simulating additional staged collisions, by comparing the results of the model to widely utilized throw distance equations, by providing guidance on inputs for the pedestrian multibody, and by providing documentation of the characteristics of the multibody pedestrian. In addition, two new staged pedestrian collisions are discussed and simulated. This study demonstrates the following: (1) The center of gravity height of the PC-Crash pedestrian model is comparable to the center of gravity height reported for pedestrians in anthropometric data. (2) The pedestrian-to-ground friction coefficient should be set using values representative of simple sliding, not values that include the impact with the ground or the airborne trajectory. (3) Based on the simulations presented in this study, a reasonable range for this pedestrian-to-ground friction coefficient for dry roadways is 0.5 to 0.65. For wet roadways, a reasonable range is 0.3 to 0.4 (4) For forward projection and wrap trajectories, the default coefficient of restitution for the multibody of 0.316 is reasonable for vehicle impact speeds below 40 km/h. (5) For speeds above 40 km/h with these trajectory types, a restitution coefficient in the range of 0.1 to 0.2 yields more accurate throw distances. (6) For fender vaults, the pedestrian-to-vehicle coefficient of friction and the coefficient of restitution are influential in the lateral throw distance, and these parameters can be treated as optimizing parameters for simulations of this trajectory type.
Rose, NathanSmith, ConnorCarter, NealMetanias, Andrew
With the increasing prevalence of Automatic Emergency Braking Systems (AEB) in vehicles, their performance in actual collision accidents has garnered increasing attention. In the context of AEB systems, the pitch angle of a vehicle can significantly alter the nature of collisions with pedestrians. Typically, during such collisions, the pedestrian's legs are the first to come into contact with the vehicle's front structure, leading to a noticeable change in the point of impact. Thus, to investigate the differences in leg injuries to pedestrians under various pitch angles of vehicles when AEB is activated, this study employs the Total Human Model for Safety (THUMS) pedestrian finite element model, sensors were established at the leg location based on the Advanced Pedestrian Legform Impactor (APLI), and a corresponding vehicle finite element model was used for simulation, analyzing the dynamic responses of the pedestrian finite element model at different pitch angles for sedan and Sport Utility Vehicle (SUV), and comparing injury indicators for the thigh, lower leg, and knee joint. The results indicate that the vehicle's pitch angle reduces the elongation of the medial collateral ligament (MCL) in the pedestrian's knee and increases the maximum bending moment of the thigh. For sedan with pitch angles, the maximum bending moment of the pedestrian's lower leg decreases at a vehicle speed of 40 km/h and increases at speeds of 30 km/h and 20 km/h. The impact of SUV on the maximum bending moment of the lower leg is opposite to that of sedan. This study holds guiding significance for optimizing vehicle design, enhancing the effectiveness of AEB systems, and establishing stricter pedestrian protection standards.
Hong, ChengYe, BinZhan, ZhenfeiLiu, YuWan, XinmingHao, Haizhou
Background. In 2022, vulnerable road user (VRU) deaths in the United States increased to their highest level in more than 40 years. At the same time, increasing vehicle size and taller front ends may contribute to larger forward blind zones, but little is known about the role that visual occlusion may play in this trend. Goal. Researchers measured the blind zones of six top-selling light-duty vehicle models (one pickup truck, three SUVs, and two passenger cars) across multiple redesign cycles (1997–2023) to determine whether the blind zones were getting larger. Method. To quantify the blind zones, the markerless method developed by the Insurance Institute for Highway Safety was used to calculate the occluded and visible areas at ground level in the forward 180° arc around the driver at ranges of 10 m and 20 m. Results. In the 10-m forward radius nearest the vehicle, outward visibility declined in all six vehicle models measured across time. The SUV models showed up to a 58% reduction in visibility within a 10 m radius. Other vehicles exhibited smaller (7%–19%) reductions. At longer distances (10 m–20 m), vehicles demonstrated both increases and decreases in visibility. Conclusion. The markerless method provides a straightforward and replicable assessment of driver visibility. The observed decrease in direct outward visibility near the vehicles points to the need for further study regarding this trend, including analysis of the repeatability and viability of the measurement technique.
Epstein, Alexander K.Brodeur, AlyssaDrake, JuwonEnglin, EricFisher, Donald L.Zoepf, StephenMueller, Becky C.Bragg, Haden
Automated driving systems (ADS) are designed toward safely navigating the roadway environment, which also includes consideration of potential conflict with other road users. Of particular concern is understanding the cumulative risk associated with vulnerable road users (VRUs) conflicts and collisions. VRUs represent a population of road users that have limited protection compared to vehicle occupants. These severity distributions are particularly useful in evaluating ADS real-world performance with respect to the existing fleet of vehicles. The objective of this study was to present event severity distributions associated with vehicle-cyclist collisions within an urban naturalistic driving environment by leveraging data from third-party vehicles instrumented with forward-facing cameras and a sensor suite (accelerometer sampling at 20 Hz and GPS [variable sampling frequency]). From over 66 million miles of driving, 30 collision events were identified. A global optimization routine was used on the accelerometer and GPS data to correct for sensor orientation and asynchronicity in data sampling. For each event, two key video frames were identified: the frame associated with impact and a frame associated with key vehicle kinematics (e.g. vehicle start/stop). These key frames were then mapped to the accelerometer and GPS data to determine vehicle speed at impact. For the events included in this dataset, impact speeds ranged from approximately 3.2 kph (2 mph) to 53.1 kph (33 mph). In 82% of events, the front of the vehicle struck the cyclist. Existing cyclist injury risk curves were then used to calculate the level of risk associated with the reconstructed impacts, and the probability of AIS3+ injury risk was observed to vary from minimal risk to approximately 30%. These data highlight the wide range of impact speeds and injury risk that may occur during vehicle-cyclist collisions.
Campolettano, Eamon T.Scanlon, John M.Kusano, Kristofer D.
Wrap around distance (WAD) is an important index to evaluate the contact position between pedestrian head and vehicle, and is also one of the key parameters of pedestrian accident reconstruction. The purpose of this paper is to explore whether the pedestrian headform testcan reflect the distribution of head injury in the real world. Firstly, in order to study the distribution of pedestrian head WAD in road accidents in China, a head WAD prediction model was established using logistic regression based on pedestrian height and vehicle collision speed. Secondly, in order to study the distribution of the risk of severe head injuries among pedestrians in accidents, the frequency of pedestrian head impact and the proportion of pedestrian head injury were counted respectively for sedans and SUVs. Subsequently, a risk curve for severe head injuries was constructed based on the head impact frequency and the proportion of severe injuries, utilizing a method that incorporates joint probability. Finally, to investigate the relationship between the headform test results and the distribution of severe head injury risks among pedestrians in road traffic accidents in China, a meticulous regional division of the head WAD was conducted based on the vehicle's front structure. A qualitative comparison was made between the distribution of headform test results in that area and the distribution of pedestrian injuries in the real world within that specific region. The results indicate that the location of pedestrian head impacts is primarily concentrated within the range of WAD 1500 mm to WAD 2300 mm. When pedestrians collide with sedans, the peak frequency of head impact occurs at WAD 1900 mm, whereas in collisions with SUVs, this peak occurs at WAD 1700 mm. In the areas of sedan windshields and A-pillars, as well as the rear portion of SUV hoods and windshield wiper regions, pedestrians' heads are most susceptible to severe injuries. It is noteworthy that within the WAD1000-WAD1500 mm range, the risk of severe head injuries for pedestrians is nearly zero. This study, through the analysis of severe head injury distribution among pedestrians in China, assessed the effectiveness and applicability of The China Insurance Automotive Safety Index (C-IASI) headform test. It provides targeted recommendations for the enhancement of the C-IASI pedestrian assessment protocol and offers crucial reference for optimizing the design of vehicle front structures.
Ye, BinLiu, YuLong, YongchengShi, LiangliangXinming, Wan
Compared to other age groups, older adults are at more significant risk of hip fracture when they fall. In addition to the higher risk of falls for the elderly, fear of falls can reduce this population’s outdoor activity. Various preventive solutions have been proposed to reduce the risk of hip fractures ranging from wearable hip protectors to indoor flooring systems. A previously developed rubberized asphalt mixture demonstrated the potential to reduce the risk of head injury. In the current study, the capability of the rubberized asphalt sample was evaluated for the risk of hip fracture for an average elderly male and an average elderly female. A previously developed human body model was positioned in a fall configuration that would give the highest impact forces toward regular asphalt. Three different rubber contents with 14, 28, 33 weight percent (% wt.) were implemented as the ground alongside one regular non-rubberized (0%) asphalt mixture, one baseline, and one extra-compliant playground rubber-composite material. The whole-body model was simulated to fall on the rubberized asphalt mixtures with an initial vertical velocity of 3 m/s with a 10° trunk angle and +10° anterior pelvis rotation. The impact forces were measured on the femoral head, and a previously developed hip fracture risk function was used to compare the rubberized asphalt mixtures. It was found that the rubberized asphalt mixture with 33% wt. rubber can reduce the impact forces up to 10% for the elderly male and female model compared to regular asphalt. The impact forces were most reduced for the extra-compliant playground material, with a 23% reduction for the female model. The risk of injury for the asphalt mixture with 33% wt. rubber was reduced up to 18% for elderly females and 20 for elderly males, compared to regular asphalt. The extra-compliant playground material had the most reduction of hip fracture risk for both sexes, 39 and 43% for elderly females and males, respectively.
Sahandifar, PooyaWallqvist, VivecaKleiven, Svein
Bus transport is an important element in a sustainable transport strategy. The objective of this study is to understand crashes and injuries involving buses, suggest potential passive-safety interventions, estimate their effectiveness, and compare their effectiveness between Germany and India. Descriptive analysis of crash data from the German In-depth Accident Study (GIDAS) and the Road Accident Sampling System India (RASSI) database was performed in two parts: First, bus passengers and their injuries were analyzed and second, pedestrian injuries in bus-to-pedestrian crashes were analyzed. Lastly, interventions were suggested, and their effectiveness was estimated. Analysis of bus passengers showed that most moderate-to-critical injuries in the GIDAS data were to the head caused by interior bus components. In the RASSI data, head injuries were also frequent, often due to bus interior contact, but also due to ejection and impact to the ground or bus exterior. As many as 31% of all moderate-to-critical injuries in RASSI occurred due to ejection, none in the GIDAS data. Negligible seatbelt usage in the GIDAS data and non-existent use in RASSI demands some explanation. In bus-to-pedestrian crashes, impacts to the front of the bus were the most frequent scenario in both countries. Head injuries were frequent in both GIDAS and RASSI, predominantly due to an impact with the bus front or the ground. To mitigate these injuries, the suggested interventions are seatbelts, pedestrian airbags, and pedestrian underrun protection. These interventions were estimated to annually save up to 180 injured pedestrians and 469 injured bus occupants in Germany, and 5,613 injured pedestrians and 36,271 injured bus occupants in India. To conclude, while the need for better data and more rigorous intervention analysis in future work are discussed, the highlighted safety issues and potential interventions can guide discussion and action plans for safer buses.
Ranmal, AartiJeppsson, HannaStrandroth, JohanLubbe, Nils
Cyclist injuries and fatalities are a world-wide concern and often a consequence of interaction with cars. The MICA2 Project (Modelling of Interactions between Cyclists and Automobiles) is aimed at protecting bicyclists from getting injured by a passing car. This study addresses the need for new protective safety systems through the development and testing of a novel external car airbag. The airbag was designed to add protection to the center side part of the car, in the B-pillar area, to protect the head of a bicyclist impacting a car in this area. Two methods were used to evaluate performance of the system. For full system tests, a Hybrid III 50th percentile male dummy was seated on a city bike and projected into the side of a car at either 30°, 60° or 90° to the car side. In additional component tests an adult pedestrian headform was launched towards the roof rail or B-pillar structure of the car. The highest injury risk was found in a perpendicular (90 degree) impact between the bicycle and car. In oblique crashes the bicycle slid along the side of the car and that decreased the linear accelerations in the head. Glancing collisions (30 degree) resulted in low injury risk as there was no direct head impact. The airbag was very effective in reducing the HIC for the dummy or headform, by about 30%, in the 90 degree impact case with dummy and more than that with the headform.
Carroll, JolyonEnanger, MikaelJeppsson, HannaLubbe, Nils
While it is recognized that collisions involve pedestrians of all sizes, this Information Report addresses performance specifications for a midsize adult male research dummy. This approach stems from the greater knowledge of biomechanics and existing dummy technologies for the midsize male relative to other adult sizes and children. While not the initial objective, it is envisioned that additional performance specifications for other sizes of pedestrian research dummies will be developed in the future based on accepted scaling procedures. The specific requirements for the pedestrian dummy have been based on a collective assessment of pedestrian injury, response, and anthropometry priorities from the experimental, epidemiologic, and computational literature. In general, the objective was to specify performance specifications based on human characteristics and the impact response of post-mortem human subjects rather than to specify the design of a particular physical device. Based on the perceived applications for a research pedestrian dummy, the primary focus of this document centered on biofidelic whole-body kinematics during a vehicle-pedestrian impact. Specific body regions were prioritized (see A.1.5) based on a combination of pedestrian injury, including both severity and frequency. Based on the priorities established by a review committee, the specifications provided in this document include both mandatory and recommended requirements as indicated by the terms “shall” and “should,” respectively. As pedestrian injury trends and dummy hardware continue to evolve in the future, it is anticipated that this document will expand to include more mandatory requirements in more body regions. Finally, it should be noted that the test procedures described in this document only apply to the specific tests required to assess pedestrian dummy biofidelity. It is anticipated that pedestrian dummies meeting the performance criteria of this document will be used in a wide variety of tests, requiring specialized test and data procedures.
Human Biomechanics and Simulations Standards Committee
Taking the pedestrian-vehicle accidents in the China in-Depth Accident Study (CIDAS) database as a sample case, 13 accidents morphological parameters were selected from three aspects: human, vehicle and environmental factors, and their depth analysis was carried out to obtain their distribution law through the card. The chi-square test and logistic regression method are used to analyze the correlation between the injury severity of pedestrians and other accidental morphological parameters in pedestrian-vehicle accidents. The results show that there is no significant correlation between gender/season and injury severity of pedestrians. The age of pedestrians and the collision speed is the strongest correlation with injury severity of pedestrians. When a pedestrian is over 65 years old, the pedestrian height is in the range of 160-170cm, the collision speed is greater than 60 kilometers per hour, and the pedestrian speed is greater than 8 kilometers per hour, the probability of pedestrian injury is significantly increased.
Lian, XiaoweiDeng, JiaLi, XudongCui, Fujun
Ground Landing Mechanisms in Vehicle-To-Pedestrian Impacts Based on Accident Video Records2018-01-10444/3/2018
Accident data have shown that the pedestrian injuries resulting from contact with the ground are serious and may even be worse than the injuries resulting from the primary contact with the vehicle. The landing mechanisms, including the pedestrian trajectory and subsequent sequential body region contacts to the ground, are the basis for understanding the ground impact injuries of pedestrians. However, the landing mechanisms of pedestrian are too complicated to be categorized via investigation of the collision information after an accident has occurred. Nowadays, pedestrian kinematics after vehicle impacts can be observed from the accident videos that have been recorded by road monitoring and driver recorders. This study was aimed at investigating the pedestrian landing mechanisms and analyzing the influencing factors. In the current study, 134 pedestrian cases (involving 136 pedestrians) were selected from the internet, and 13 types of landing mechanisms were classified according to the fall kinematics and landing posture. Our results show that pedestrians who were thrown forward and hit the ground without a clear rotational tendency (ground landing mechanism II) accounted for the highest frequency, 49.3% in all cases. The landing mechanisms of pedestrians were affected by impact velocities and kinematic trajectories during vehicle impacts. The results of this study can benefit the development of vehicle safety systems that reduce pedestrian ground impact injuries.
Li, QuanHan, YongMizuno, Koji
The goal of the Pedestrian Test Mannequin Task Force is to develop standard specifications/requirements for pedestrian test mannequins (1 adult and 1 child) that are representative of real pedestrians to the sensors used in Pedestrian Detection systems and can be used for performance assessment of such in-vehicle systems (including warning and/or braking) in real world test scenarios/conditions. This version of the document only includes the pedestrian mannequin for vision, Lidar, and/or 76 to 78 GHz radar based Pedestrian Pre-collision systems.
Active Safety and Driver Support Systems Standards Committee
This document provides recommendations of safety message minimum performance requirements between a Vulnerable Road User (VRU) and a vehicle. It addresses the transmission of Personal Safety Messages (PSM) from road user devices carried by pedestrians, bicycle riders and public safety personnel, to provide driver and vehicle system awareness and potentially offer safety alerts to VRUs. This document includes the recommendation of standards profiles, function descriptions and minimum performance requirements for transmitting the SAE J2735-defined PSM [1] over a Dedicated Short Range Communications (DSRC) Wireless communication link as defined in the Institute of Electrical and Electronics Engineers (IEEE) 1609 and the IEEE 802.11 Standards [[1]]-[5]]. While other wireless media may be used to deliver the PSM, DSRC is explicitly assumed in this document, because of anticipated regulatory ruling in the United States and other countries requiring vehicles to be equipped with a DSRC-based safety system using V2V communication. This recommended practice is limited at this time to communications between the VRU device carried by walking pedestrians and DSRC equipped vehicles. Later versions may incorporate improvements based on field experience with this recommended practice and may include other provisions for communicating with other DSRC equipped devices, and with other VRUs.
V2X Core Technical Committee
This study aimed to clarify the relationship between truck-pedestrian crash impact velocity and the risks of serious injury and fatality to pedestrians. We used micro and macro truck-pedestrian accident data from the Japanese Institute for Traffic Accident Research and Data Analysis (ITARDA) database. We classified vehicle type into five categories: heavy-duty trucks (gross vehicle weight [GVW] ≥11 × 103 kg [11 tons (t)], medium-duty trucks (5 × 103 kg [5 t] ≤ GVW < 11 × 103 kg [11 t]), light-duty trucks (GVW <5 × 103 kg [5 t]), box vans, and sedans. The fatality risk was ≤5% for light-duty trucks, box vans, and sedans at impact velocities ≤ 30 km/h and for medium-duty trucks at impact velocities ≤20 km/h. The fatality risk was ≤10% for heavy-duty trucks at impact velocities ≤10 km/h. Thus, fatality risk appears strongly associated with vehicle class. The results also revealed that a 10 km/h reduction in impact velocities could mitigate the severity of pedestrian injuries at impact velocities ≥30 km/h for all five analyzed vehicle types. Therefore, serious injuries and fatalities to pedestrians could be decreased by the development and deployment of collision mitigation systems (CMSs) to all vehicles, including to commercial trucks, because CMSs can detect pedestrians in even severe conditions, such as when the drive’s view is obstructed, and can reduce the impact velocity. The present results indicate that CMS design specifications should differ between vehicle types because of the strong dependence of serious-injury and fatality risks on vehicle type.
Matsui, YasuhiroOikawa, ShokoSorimachi, KazuhiroImanishi, AkiraFujimura, Takeshi
Model-Based Design (MBD) has been widely used for automotive embedded software design. Automobile manufacturers and suppliers have often underlined the importance of an unified approach for electrical and electronic (E/E) system design. In this scenario, MBD can provide a mutual benefit for stakeholders due to the share of information, workflow, and tool-chain. In this paper, we highlight MBD application for automotive Exterior Lighting System (ELS) design. In fact, ELS is an event-driven control system typically needed for car lighting and signalization, in particular at night. Furthermore, this system is mandatory for every road vehicle according to current Brazilian laws and legislation. Also, it provides safety drive preventing car accidents and pedestrian injury. In this context, we present how to boost ELS design using MBD concepts. ELS was developed in three MBD workflow (Model-In-the-Loop, Software-In-the-Loop, and Processor-In-the-Loop), from supplier’s viewpoint. The results highlight how MBD can provide better system design leading to significant automotive embedded software quality improvement. Function’s integration and software architecture is an ongoing research project and it will be considered in future work. The paper is organized as follow. Second section presents a brief literature review of the research domain. Third section shows MBD workflows for ELS design. Last section highlights concluding remarking and future work.
Neme, João HenriqueSantos, Max Mauro DiasTeixeira, Evandro Leonardo Silva
In a car accident which is involving pedestrians, head injuries occur very frequently as the head of the pedestrian hits the windshield. The head injury criterion (HIC) obtained through the windshield impact test is used to evaluate the pedestrian injury, and car manufacturers are trying to meet the criterion by changing the design and/or materials.. However, there are some difficulties in the windshield impact test, e.g. a large scatter of the test data or windshield shape-dependent property of the test. These problems make it very difficult to obtain the meaningful results from single test and thus, tests should be executed several times. In this study, a lab-scale windshield impact test was performed using a modified instrumented dart impact (IDI) tester. Tests were carried out by switching test conditions such as the impact speed, the size of the head form and the specimen thickness. The key results such as acceleration and displacement curves of a head form, peak values from the acceleration curve, cracking modes, etc. were compared for various test conditions. In addition, the numerical simulation was carried out to correlate the lab-scale test results with full-scale windshield impact test, and the correlation between the lab-scale simulation result and full-scale simulation result of the earlier study is discussed.
Moon, Sung WookKang, ByunghyunLim, JaeyoungChoi, Byoung-Ho
Each year, more than 270,000 pedestrians lose their lives on the world's roads. Globally, pedestrians constitute 22% of all road traffic fatalities, and in some countries this proportion is as high as two thirds of all road traffic deaths. Millions of pedestrians are non-fatally injured and some of whom are left with permanent disabilities. These incidents cause much suffering and grief as well as economic hardship. To lower the rate of pedestrian injuries and fatalities, the Euro-Ncap committee adopted an overall impact star-grade system in 2009, making the pedestrian protection cut-off score required to obtain the best impact-star grade more stringent until 2016. It is very difficult to surpass the enhanced pedestrian cut-off score using past methods. In this paper, I determine the hood's worst-performing areas in terms of pedestrian protection by analyzing previous pedestrian test results. To improve performance at these areas, I developed a Damping latch & hinge and a 3-corner rearward pop-up system. I then proceeded to optimize the design of the hood inner panel, Long hood + Damping latch & hinge, and 3-corner rearward pop-up systems. Each system was put through a real vehicle pedestrian protection test to verify that it could improve pedestrian protection performance at the designated areas. As a result, we found that a 3-corner rearward pop-up system is the best method for pedestrian protection with consideration for cost, weight, and design.
Yang, Seung Jun
Globally, road traffic crashes kill about 1.24 million people each year. Pedestrians constitute 22% of all road deaths, and in some countries this is as high as 60%. The capacity to respond to pedestrian safety is an important component of efforts to prevent road traffic injuries. Pedestrian collisions, like other road traffic crashes, should not be accepted as inevitable because they are, in fact, both predictable and preventable. Examination of pedestrian injury distribution reveals that given an impact speed, the probability of fatal injuries is substantially greater when the striking vehicle is a pick-up rather than a passenger car. Given their utility areas, pickup vehicles require negotiating rough terrains and are therefore engineered with higher ground clearance and larger approach angle. The challenge is to optimize these design parameters and also style the vehicle for pedestrian safety while maintaining a low design cost at the same time. This document presents methodology and a set of solutions to meet pedestrian impact safety for pickup vehicles as per the guidelines recommended by Regulation (EC) No 78/2009, of the European Parliament and of the Council of 14 January, 2009. Pedestrian lower leg simulation is performed on LS DYNA with an Impactor propelled at a speed of 40Km/h towards the front end of the pickup vehicle. Head injury risk is assessed separately for adults and for children by identifying Head Impact Zones for both in CAD software CAVA CATIA. Head impact simulation is then performed in the relevant parts of the bonnet top area using LS DYNA software. The results thus obtained are used to optimize vehicle's front end to meet pedestrian safety requirements.
Pathak, Amit KamalakarRajke, MayurMadiyan, Anupama
Pedestrians and bicyclists account for a significant share of deaths and serious injuries in the road transport system. The protection of pedestrians in car-to-pedestrian crashes has therefore been addressed by friendlier car fronts and since 1997, the European New Car Assessment Program (Euro NCAP) has assessed the level of protection for most car models available in Europe. In the current study, Euro NCAP pedestrian scoring was compared with real-life injury outcomes in car-to-pedestrian and car-to-bicyclist crashes occurring in Sweden. Approximately 1200 injured pedestrians and 2000 injured bicyclists were included in the study. Groups of cars with low, medium and high pedestrian scores were compared with respect to pedestrian injury severity on the Maximum Abbreviated Injury Scale (MAIS)-level and risk of permanent medical impairment (RPMI). Significant injury reductions to both pedestrians and bicyclists were found between low and high performing cars. For pedestrians, the reduction of MAIS2+, MAIS3+, RPMI1+ and RPMI10+ ranged from 20-56% and was significant on all levels except for MAIS3+ injuries. Pedestrian head injuries had the highest reduction, 80-90% depending on level of medical impairment. For bicyclist, an injury reduction was only observed between medium and high performing cars. Significant injury reductions were found for all body regions. It was also found that cars fitted with autonomous emergency braking including pedestrian detection might have a 60-70% lower crash involvement than expected. Based on these results, it was recommended that pedestrian protection are implemented on a global scale to provide protection for vulnerable road users worldwide.
Strandroth, JohanSternlund, SimonLie, AndersTingvall, ClaesRizzi, MatteoKullgren, AndersOhlin, MariaFredriksson, Rikard
Global regulations intended to enhance pedestrian protection in a vehicle collision, thereby reducing the severity of pedestrian injuries, are presenting significant challenges to vehicle designers. Vehicle hoods, for example, must absorb a significant amount of energy over a small area while precluding impact with a hard engine compartment component. In this paper, a simple passive approach for pedestrian protection is introduced in which thin metal alloy sheets are bent to follow a C-shaped cross-sectional profile thereby giving them energy absorbing capacity during impact when affixed to the underside of a hood. Materials considered were aluminum (6111-T4, 5182-O) and magnesium (AZ31-O, AZ61-O, ZEK100) alloys. To evaluate the material effect on the head injury criterion (HIC) score without a hood, each C-channel absorber was crushed in a drop tower test using a small dart. Two high speed cameras captured dart image data before and during impact from which HIC scores were computed with stereo digital image correlation (DIC). The only absorber material that fractured during impact, Mg AZ31-O, had the lowest and hence most favorable HIC score relative to those materials that crushed without fracturing. Test results were then compared with predictions from finite element (FE) simulations of the dart impact tests for Mg AZ31-O and Al 5182-O. Good correlation between the tests and simulations was achieved indicating that FE simulations can reliably be used in material selection and design optimization of energy absorbers as passive means for pedestrian protection.
Savic, VesnaPawlicki, MatthewKrajewski, PaulVoss, MarkHector, LouisSnavely, Keith
While the number of traffic fatalities as a whole continues to decline steadily over time, the number of pedestrian fatalities continues to rise (up 8% since 2009) and comprises a larger fraction of these fatalities. In 2011 there were 4,432 pedestrians killed and an estimated 69,000 pedestrian injuries [1]. A new generation of Pedestrian Pre-Collision Systems (PCS) is being introduced by car manufactures to mitigate pedestrian injuries and fatalities. In order to evaluate the performance of pedestrian PCS, The Transportation Active Safety Institute (TASI) at Indiana University-Purdue University Indianapolis is developing a set of test scenarios and procedures for evaluating the performance of pedestrian PCS with the support of the Collaborative Safety Research Center of Toyota. Pedestrian crashes are complex in that there are many aspects about location, driver behavior, and pedestrian behaviors that may have implications for the performance of the PCS. This complexity will generate far more scenarios than can be reasonably tested. This paper describes a test scenario selection process that uses not only the percentage importance of crash scenarios in terms of combinations of variables, but also ensures that individual variables are adequately represented in the chosen tests. The total number of test scenarios can be specified based on the percentage representation coverage according to the crash data or by the testing agency. The advantage of this method is that both important scenarios and important scenario variable values are guaranteed to be included in the set of test scenarios. The proposed method is demonstrated using GES and FARS pedestrian crash data for 2010 and 2011. The crash scenarios are described with variables that can be used for setting up vehicle tests, such as the pedestrian sizes, light conditions, pedestrian motion directions, pedestrian motion behavior/speeds, vehicle motion directions, and vehicle motion speeds. This method can also be used for creating a parsimonious set of test scenarios for other vehicle active safety features.
Chien, StanleyYi, QiangGood, DavidGholamjafari, AliChen, YaobinSherony, Rini
The first purpose of this study is to clarify the relation between the car impact velocity and pedestrian injury severity or mortality risk. We investigated the frequency of serious injuries and fatalities of pedestrians using vehicle-pedestrian accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, minivans, and box vans (ordinary automobiles) and light passenger cars and light cargo vans (light automobiles). The results revealed that a 10-km/h reduction in impact velocity could mitigate severe pedestrian injuries in cases involving impact velocities of 40 km/h or more for the five vehicle types analyzed. Specifically, if the impact velocity was 30 km/h or less, the frequency of serious injuries was less than 27% and the frequency of fatalities was less than 5% for the five vehicle types. Therefore, if the collision damage mitigation braking system (CDMBS) that uses a sensor to detect pedestrians can effectively reduce the impact velocity for various vehicle types, pedestrian injuries will be greatly mitigated. The second purpose of this study is to identify the factors that affect injury risk. Impact experiments were conducted in which a sedan impacted against a pedestrian full-scale dummy at 40 km/h and a pedestrian headform impactor was impacted against a road surface. The results indicated that the risk of pedestrian serious injury was significantly affected by multiple impact conditions, such as the pedestrian height, car impact velocity, car frontal shape, and car stiffness in cases where the car impacted the pedestrian's head, the degrees of influence of which were driven by the vehicle impact velocity.
Matsui, YasuhiroOikawa, ShokoAndo, Kenichi
Pedestrian protection evaluations have been developed to encourage vehicle front-end designs that mitigate the consequences of vehicle-to-pedestrian crashes. The European New Car Assessment Program (Euro NCAP) evaluates pedestrian head protection with impacts against vehicle hood, windshield, and A-pillars. The Global Technical Regulation No. 9 (GTR 9), being evaluated for U.S. regulation, limits head protection evaluations to impacts against vehicle hoods. The objective of this study was to compare results from pedestrian head impact testing to the real-world rates of fatal and incapacitating injuries in U.S. pedestrian crashes. Data from police reported pedestrian crashes in 14 states were used to calculate real-world fatal and incapacitating injury rates for seven 2002-07 small cars. Rates were 2.17-4.04 per 100 pedestrians struck for fatal injuries and 10.45-15.35 for incapacitating injuries. Euro NCAP style pedestrian headform tests were conducted against windshield, A-pillar, and hoods of the study vehicles. When compared with pedestrian injury rates, the vehicles' Euro NCAP scores, ranging 5-10 points, showed strong negative correlations (−0.6) to injury rates, though none were statistically significant. Data from the headform impacts for each of the study vehicles were used to calculate that vehicle's predicted serious injury risk. The predicted risks from both the Euro NCAP and GTR 9 test zones showed high positive correlations with the pedestrian fatal and incapacitating injury rates, though few were statistically significant. Whether vehicle stiffness is evaluated on all components of vehicle front ends (Euro NCAP) or is limited to hoods (GTR 9), softer vehicle components correspond to a lower risk of fatality.
Mueller, BeckyFarmer, CharlesJermakian, JessicaZuby, David
Most studies of pedestrian injuries focus on reducing traumatic injuries due to the primary impact between the vehicle and the pedestrian. However, based on the Pedestrian Crash Data Study (PCDS), some researchers concluded that one of the leading causes of head injury for pedestrian crashes can be attributed to the secondary impact, defined as the impact of the pedestrian with the ground after the primary impact of the pedestrian with the vehicle. The purpose of this study is to understand if different vehicle front-end profiles can affect the risk of pedestrian secondary head impact with the ground and thus help in reducing the risk of head injury during secondary head impact with ground. Pedestrian responses were studied using several front-end profiles based off a mid-size vehicle and a SUV that have been validated previously along with several MADYMO pedestrian models. Mesh morphing is used to explore changes to the bumper height, bonnet leading-edge height, and bonnet rear reference-line height. Simulations leading up to pedestrian secondary impact with ground are conducted at impact speeds of 40 and 30 km/h. In addition, three pedestrian sizes (50th, 5th and 6yr old child) are used to enable us to search for a front-end profile that performs well for multiple sizes of pedestrians, not just one particular size. In most of the simulations, secondary ground impact with pedestrian head/neck/shoulder region occurred. However, there were some front-end profiles that promoted secondary ground impact with pedestrian lower extremities, thus avoiding pedestrian secondary head impact with ground. Previous pedestrian safety research work has suggested the use of active safety methods, such as ‘pop up hood’, to reduce pedestrian head injury during primary impact. Accordingly, we also conducted simulations using a model with the hood raised to capture the effect of a pop-up hood. These simulations indicated that even though pop-up hood helped reducing the head injury criterion during primary impact, it changed the overall pedestrian kinematics in some cases. The specific design with pop up hood evaluated in this study did not prevent pedestrian head secondary impact with the ground or actually led to more severe pedestrian secondary head impact with the ground.
Gupta, VishalYang, King H.
Lumbar Injury BiomechanicsPT-1538/1/2013
The amount of load that can be borne by the different components of the lumbar region is fairly well understood, as are resulting injuries from overloading. Less severe lumbar injuries involve a wide range of factors, including: heredity, obesity, age, occupation, sports, cardiovascular risk factors, and depression. Some of the most painful conditions that require high levels of care involve lumbar spine fracture or soft tissue injury from falls, contact sports, vehicle collisions, aircraft ejection, and underbody blasts from roadway explosions (military injuries). Each of these injury scenarios elicits a different kinematic response of the spine as a result of load direction, magnitude, and duration. Updated from a popular earlier volume, this new compendium includes landmark papers from 1994 through 2013 that focus exclusively on lumbar injuries. It also features an introductory chapter, “Blunt Lumbar Trauma” that provides an overview of the anatomy of the lumbar region, injury, and injury mechanisms, as well as an extensive literature update. This edition is the third in a series of biomechanics compendia edited by Mr. Pike. Earlier editions covered injuries of the neck and head. For this volume, Mr. Pike and the advisory panel selected 15 of the best papers from a variety of sources including SAE International, IRCOBI, Stapp, NHTSA, ESV, and the Association for the Advancement of Automotive Medicine. The book will be helpful to those studying lumbar injury from a broad range of causes, including transportation, falls, sports, personal violence, and blast-related. Professionals from a variety of disciplines will find the book useful: biomechanics, accident reconstruction, medical and rehabilitation, insurance, legal, and law enforcement.
Pike, Jeffrey A.
Injuries in car to pedestrian collisions are affected by various factors such as the vehicle body type, pedestrian body size and impact location as well as the collision speed. This study aimed to investigate the influence of such factors taking a Finite Element (FE) approach. A total of 72 collision cases were simulated using three different vehicle FE models (Sedan, SUV, Mini-Van), three different pedestrian FE models (AM50, AF05, AM95), assuming two different impact locations (center and the corner of the bumper) and at four different collision speeds (20, 30, 40 and 50 km/h). The impact kinematics and the responses of the pedestrian model were validated against those in the literature prior to the simulations. The relationship between the collision speed and the predicted occurrence of head and chest injuries was examined for each case, analyzing the impact kinematics of the pedestrian against the vehicle body and resultant loading to the head and the chest. Strain based indicators were used in the simulation model to estimate skeletal injury (bony fracture) and soft tissue (brain and internal organs) injury. The study results primarily showed that the injury risk became higher with the collision speed, but was also affected by the combination of the factors such as the pedestrian size and the impact location. The study also discussed the injury patterns and trends with respect to the factors examined. In all of the simulated conditions, the model did not predict any severe injury at a collision speed of 20 km/h.
Watanabe, RyosukeKatsuhara, TadasukeMiyazaki, HiroshiKitagawa, YuichiYasuki, Tsuyoshi
With many vehicles now achieving high marks in NCAP frontal and side impact, many countries around the world are considering or have already implemented pedestrian impact protocols to help address these types of crashes, due to the incidence rate of pedestrian injuries and fatalities. The leading global protocol put forth by the working party No. 29 (WP29) of the United Nations is the Global Technical Regulation (GTR) [1], which includes testing that simulates a pedestrian's head impacting a vehicle's hood through the use of a free flight head form. In conducting this test, it is important to be aware of the sources of variation inherent in the testing equipment and testing methodology so that steps can be taken to mitigate their influence. Testing facilities that can maintain high standards of repeatability can be relied on for producing valid tests that meet the GTR tolerances as well as maintaining reasonable costs and testing throughput. This paper will present a study of the various factors in the test setup and method that can introduce variation to the head form speed and impact point accuracy. Furthermore, the authors will present a novel design for the impactor arm that dampens the recoil that occurs during the launching of the pedestrian head form to improve the test accuracy and long term durability of the equipment.
Grattan, PatrickDix, JeffNastovski, Jovo
Pedestrian crashes are the most frequent cause of traffic-related fatalities worldwide. The high number of pedestrian accidents justifies more active research work on passive and active safety technology intended to mitigate pedestrian injuries. Post-impact pedestrian kinematics is complex and depends on various factors such as impact speed, height of the pedestrian, front-end profile of the striking vehicle and pedestrian posture, among others. The aim of this study is to investigate the main factors that determine post-crash pedestrian kinematics. The injury mechanism is also discussed. A detailed study of NASS-PCDS (National Automotive Sampling System - Pedestrian Crash Data Study, US, 1994-1998), showed that the vehicle-pedestrian interaction in frontal crashes can be categorized into four types: “Thrown forward”, “Wrapped position”, “Slid to windshield” and “Passed over vehicle”. A Principal Component Analysis (PCA) was performed and 11 independent factors were identified for study from a set of 26 variables, as defined in NASS-PCDS. Pedestrian-vehicle size ratio and the impact speed are the two most influential factors that determine post crash pedestrian kinematics. However, the standing posture of a taller pedestrian can also cause rotational movement around the local Z axis, leading to a face-up/down mode of head-face impact before falling on the hood. The findings from the NASS-PCDS study were also confirmed and verified with the help of numerical simulations performed using two modified JAMA human FE models. An adult model (male, 175cm and 72kg) and a properly scaled child model (6 years old, 120cm and 21kg) were effectively utilized to investigate the post-crash kinematics in different conditions.
Kawabe, YoshikoAsai, ToshiyukiMurakami, DaisukePal, ChinmoyOkabe, Tomosaburo
The e-born₃ is an innovative urban electric vehicle which can be easily transformed from a van to a passenger vehicle. The e-born₃ was created from scratch as an electric vehicle, which permits greater versatility in component packaging and volume usage. The innovative character of the e-born₃ is developed along three lines: passive safety performance, vehicle energy efficiency and the ergonomic considerations linked to the interior layout. The elimination of conventional combustion engine powertrain elements together with the use of wheel-embedded electric motors leads to certain freedom when packaging and designing the body in white and vehicle interior. This freedom enables improvement of the passive safety performance by permitting innovative concepts, such as an innovative layout of the driver and passengers or a short vehicle front end that minimizes pedestrian injuries. The different combination of types of closures achieves a versatile range of utilization, from taxi to load carrier and family usage. The second goal of the e-born₃ was optimal energy management. The placement of the electric motor on the wheels permits a very clean external body design, which leads to important advantages regarding vehicle aerodynamics. The e-born₃ exterior body design includes a clean smooth under body, together with closed front-end grilles and an upper-bonnet optimized by means of CFD simulation, which means minimal Cd in its class. The third main innovation is the vehicle concept itself and the versatility of usage. The e-born₃ can be easily transformed from a passenger vehicle to a van by converting the four rear seats into a flat floor. Furthermore, the e-born₃ includes innovative concepts, such as, front and rear independent HVAC systems, two separate loading spaces in the taxi configuration, etc. To sum up, the e-born₃ is an optimal solution for the urban mobility of persons and goods, regarding safety, vehicle efficiency and usage versatility.
Chimeno, Robert
The number of traffic deaths in Japan was 4,863 in 2010. Pedestrians account for the highest number (1,714, 35%), and vehicle occupants the second highest (1,602, 33%). Pedestrian protection is a key countermeasure to reduce casualties in traffic accidents. A striking vehicle's impact velocity could be considered a parameter influencing the severity of injury and possibility of death in pedestrian crashes. A collision damage mitigation braking system (CDMBS) using a sensor to detect pedestrians could be effective for reducing the vehicle/pedestrian impact velocity. Currently in Japan, cars equipped with the CDMBS also have vision sensors such as a stereo camera for pedestrian detection. However, the ability of vision sensors in production cars to properly detect pedestrians has not yet been established. The effect of reducing impact velocity on the pedestrian injury risk has also not been determined. The first objective of this study is to evaluate the performance of the CDMBS in detecting pedestrians when it is installed in production cars. The second objective of this study is to evaluate the effect of reducing impact velocity on mitigating pedestrian injury. Firstly, impact experiments were performed using a car with the CDMBS in which the car collided with a pedestrian surrogate. In these tests, the velocity was chosen for the various test runs to be 20, 40 and 60 km/h, respectively, which were based on the velocity distribution in real-world pedestrian crashes. The results indicated that the impact velocity reduction ranged approximately from 10 to 15 km/h at the standing location of a pedestrian surrogate at both daytime and nighttime lighting conditions. These results show that the system has the potential to reduce pedestrian casualties from car-to-pedestrian contacts. Secondly, finite-element analyses were performed simulating vehicle-to- pedestrian impacts with the THUMS pedestrian models. The vehicle models selected for the study included a medium sedan, a minicar, and an SUV. Since head and chest injuries are the most typical causes of pedestrian deaths in car-to-pedestrian accidents, the risk of head and chest injuries was calculated when the impact velocity was reduced from 50 km/h to 40 km/h, 30km/h, and 20 km/h. The results revealed that an impact velocity reduction of 10 km/h mitigated severe pedestrian injury at impact velocities greater than or equal to 40 km/h. Specifically, a significant effect was observed in collisions with the medium sedan and SUV. In Japan, the CDMBS has just started to be installed in medium sedans. The pedestrian injury mitigation will be greatly improved if the system can be applied to various types of vehicles including SUVs in the future.
Matsui, YasuhiroHan, YongMizuno, Koji
This report reviews current1 quantitative data on human tolerance levels without recommending specific limits. Data developed on humans (including cadavers) are presented where available; however, in many cases animal data are provided where no suitable human results have been reported. This report confines itself, as much as possible, to information of direct use to the automotive designer and tester. Data of only academic interest are largely omitted; therefore, J885 should not be considered as a complete summary of all available biomechanical data. Most of the data cited in this report applies to adult males since little information is available on women or children. The summary data provided in the tables should be considered in conjunction with the accompanying descriptive test. This material explains the manner in which the data were obtained and provides an insight as to their limitations.
Human Biomechanics and Simulations Standards Committee
While it is recognized that collisions involve pedestrians of all sizes, this Information Report addresses performance specifications for a midsize adult male research dummy. This approach stems from the greater knowledge of biomechanics and existing dummy technologies for the midsize male relative to other adult sizes and children. While not the initial objective, it is envisioned that additional performance specifications for other sizes of pedestrian research dummies will be developed in the future based on accepted scaling procedures. The specific requirements for the pedestrian dummy have been based on a collective assessment of pedestrian injury, response, and anthropometry priorities from the experimental, epidemiologic, and computational literature. In general, the objective was to specify performance specifications based on human characteristics and the impact response of post-mortem human subjects rather than to specify the design of a particular physical device. Based on the perceived applications for a research pedestrian dummy, the primary focus of this document centered on biofidelic whole-body kinematics during a vehicle-pedestrian impact. Specific body regions were prioritized (see A.1.5) based on a combination of pedestrian injury, including both severity and frequency. Based on the priorities established by a review committee, the specifications provided in this document include both mandatory and recommended requirements as indicated by the terms “shall” and “should,” respectively. As pedestrian injury trends and dummy hardware continue to evolve in the future, it is anticipated that this document will expand to include more mandatory requirements in more body regions. Finally, it should be noted that the test procedures described in this document only apply to the specific tests required to assess pedestrian dummy biofidelity. It is anticipated that pedestrian dummies meeting the performance criteria of this document will be used in a wide variety of tests, requiring specialized test and data procedures.
Human Biomechanics and Simulations Standards Committee
The materials included in this J document are not intended to represent a complete summary of pedestrian safety research activities, but are rather a collection of materials which can be helpful to users of SAE J2782.
Human Biomechanics and Simulations Standards Committee
Hood development of internal structures in vehicles is an important alternative to minimize the injuries to pedestrians in case of a running over accident. In fact, according to Berg et al (2002), about 17% of head impacts occur on the hood. Moreover, according to Farooq and Schuster (2003), 62% of fatal injuries are caused by head trauma. This study focuses on evaluating the influence of free space between the hood and rigid components, considering cut out hood inner panel design, which is one of the geometries most commonly used by auto industries. The major advantage of this structure is its weight, leading, however, to small stiffness. Injuries to the head of a pedestrian is measured through a finite element model, in accordance with the European Committee for improvement in vehicle safety. There are several ways to measure the damage caused by the deceleration of the head. Here, the measure HIC (Head Injury Criteria), created by the NHTSA (National Highway Transport Safety Association) in 1971, is chosen, since it is still the most used and recommended method in the literature. Finally, the analyses of the numerical results lead to practical suggestions for auto industry.
Ferreira, Anderson SirolliDriemeier, Larissa
Over half of the 1.2 million annual traffic fatalities worldwide are pedestrians struck by motor vehicles [ 1 ]. Medical databases, such as the National Inpatient Sample (NIS), have been utilized to ascertain injury patterns in the general population of injured pedestrians [ 2 - 3 ]. However, the authors are not aware of any studies investigating how factors, such as physical impairments, intoxication, and pre-existing medical implants (e.g. hip replacement, artificial knee, etc.) affect the prevalence of pedestrian accidents or injury outcomes. Five to eight million inpatient hospitalization records are included in the NIS annually, and this large sample size allows for analyses that are not possible with smaller data sets on pedestrian injuries. The current study utilizes the NIS to evaluate how several factors such as blindness, deafness, intoxication, and pre-existing medical implants affect injury patterns when compared to the general population of hospitalized pedestrians. In the deaf population, the most common injury diagnoses involved the head, face, and neck, whereas in the blind and medical device populations, the most common injury diagnoses involved the lower extremities. Intoxicated individuals accounted for almost 20% of injured pedestrians, and the injury patterns of the intoxicated pedestrians were largely similar to the control population, although some statistically significant differences were found. Further breakdowns of the injury patterns in each of these populations are presented and discussed.
Heller, MichellePrange, MichaelOng, KevinWatson, HeatherIyer, MadhuIvarsson, B. JohanFisher, Jacob
Each year, over half of the world's 1.17 million fatalities resulting from traffic collisions are pedestrians (World Bank, 2008). Mitigation of such fatalities and serious injuries requires a thorough understanding of the common injury mechanisms that occur in pedestrian impacts. Studying the frequency of injury to each body region and how injury patterns are related may provide additional insight into pedestrian injury mechanisms, which could be used to develop additional prevention strategies. There is a wealth of information regarding pedestrian collisions within national databases that have not been extensively used to investigate these issues to date. This paper presents a review of selected databases that contain information regarding injuries to pedestrians who have been involved in a motor vehicle collision, including the strengths and weaknesses of each in performing this type of analysis. The National Inpatient Sample (NIS) database was utilized to perform statistical analysis on the types and patterns of injuries sustained in pedestrian collisions, with supporting information being provided from other related databases. This analysis demonstrated a high likelihood of lower extremity and head injuries in pedestrians involved in a motor vehicle collision and provided further details regarding these injuries. Additionally, common injury patterns were explored by evaluating the co-diagnoses codes for the most prevalent injuries.
Heller, Michelle F.Watson, Heather N.Ivarsson, B. JohanPrange, Michael T.Fisher, Jacob L.
A Comparative Analysis of the Pedestrian Injury Risk Predicted by Mechanical Impactors and Post Mortem Human Surrogates2008-22-002011/3/2008
The objective of this study is to compare the risk of injury to pedestrians involved in vehicle-pedestrian impacts as predicted by two different types of risk assessment tools: the pedestrian subsystem impactors recommended by the European Enhanced Vehicle-Safety Committee (EEVC) and post-mortem human surrogates (PMHS). Seven replicate full-scale vehicle-pedestrian impact tests were performed with PMHS and a mid-sized sedan travelling at 40 km/h. The PMHS were instrumented with six-degree-of-freedom sensor cubes and sensor data were transformed and translated to predict impact kinematics at the head center of gravity, proximal tibiae, and knee joints. Single EEVC WG 17/EuroNCAP adult headform, upper legform and lower legform impactor tests of the same vehicle were selected for comparison based on the proximity of their impact locations to that of the PMHS. The PMHS experienced higher HIC values (1830/2160) and lower impact velocities (8.5/7.5 m/s) than the impactor (1532 and 11.1 m/s) in impacts at the lower fourth of the windshield. The lower legform impactor (31 degrees) and PMHS (right: 25-40 degrees, and left: 24-39 degrees) predicted similar maximum knee bending angles. Some PMHS tibial accelerations (114-613 g) exceeded the proposed acceptance criteria (150-200 g) in both the absence and presence of distal tibial fracture, with the impactor predicting a similar result (335 g). The upper legform impactor test resulted in bending moments (361 Nm) and forces (6.3 kN) exceeding the acceptance criteria, while PMHS sustained pelvic injuries in 6 out of 7 tests.
Kerrigan, Jason R.Crandall, Jeff R.Deng, Bing
Influence of Vehicle Body Type on Pedestrian Injury Distribution2005-01-18764/11/2005
Pedestrian impact protection has been a growing area of research over the past twenty or more years. The results from many studies have shown the importance of providing protection to vulnerable road users as a means of reducing roadway fatalities. Most of this research has focused on the vehicle fleet as a whole in datasets that are dominated by passenger cars (cars). Historically, the influence of vehicle body type on injury distribution patterns for pedestrians has not been a primary research focus. In this study we used the Pedestrian Crash Data Study (PCDS) database of detailed pedestrian crash investigations to identify how injury patterns differ for pedestrians struck by light trucks, vans, and sport utility vehicles (LTVs) from those struck by cars. AIS 2+ and 3+ injuries for each segment of vehicles were mapped back to both the body region of the pedestrian injured and the vehicle source linked to that injury in the PCDS database. The findings indicate that the head is the most frequently injured body region for both vehicle segments, but the lower extremity is second for cars, whereas the torso is second for LTVs. Mapping the injuries back to the vehicles we find that the most frequent sources of injury for cars are the windshield and bumper, while for the LTVs it is the hood and hood leading edge.
Longhitano, DouglasHenary, BasemBhalla, KaviIvarsson, JohanCrandall, Jeff
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