Browse Topic: Crashes

Items (6,373)
This article presents a novel finite element modeling approach to predict the mechanical response of jellyrolls in large-scale explicit crash simulations up to the experimental occurrence of internal short-circuit. The proposed simplified layered model embeds membrane elements within a solid element mesh to improve the prediction in load cases dominated by the buckling and sliding of the jellyroll’s layered structure. The model was validated against experimental results from in-plane, out-of-plane, and bending tests on jellyroll samples extracted from prismatic lithium-ion cells. The experimental results confirmed the jellyroll’s high compressibility under out-of-plane loads and its behavior as a collection of unconnected layers under in-plane and bending loading. Compared to the widely used crushable foam model, the simplified layered model offered additional flexibility, especially for in-plane and bending load cases. Additionally, it meets critical time increment requirements for
Cioni, DanieleMorin, DavidStrating, ArjanKizio, StephanCostas, Miguel
To estimate risk of concussion, risk functions based on injuries occurring in sports are often used. A range of datasets have been used to develop injury risk functions for concussion based on either global kinematics or tissue-level predictors. Two such datasets are one from American football, and another one from Australian football and rugby. These two datasets constitute the largest published collections of video-verified concussive cases in sports with known kinematics suitable for constructing risk functions. The objective of this study was to analyze the differences between two datasets of concussion for injury predictions to better understand the influence on injury risk functions. The kinematics were applied to the KTH head model and risk functions for different kinematic- and tissue-based predictors were developed and compared. The accuracy, sensitivity, specificity, and AUC were also compared. The two datasets evaluated in this study generated different risk curves. The
Fahlstedt, MadelenMeng, ShiyangPatton, DeclanMcIntosh, Andrew S.Kleiven, Svein
This study developed a new multibody model that accurately represents the collision behavior of crash test dummies using PC-Crash. The model replicates the shape and weight of an actual dummy. To investigate the influence of joint structures on collision behavior, an additional multibody model was developed to reproduce the joint structure of the actual dummy. These models were applied to analyze occupant behavior in a full-frontal rigid barrier and pedestrian behavior in a vehicle-to-pedestrian impact experiments. A comparison of the multibody model simulations with actual dummy impact experiments revealed that the behavior of the multibody model, which simulates the joint structure of the dummy, closely matched that of the actual dummy. The results indicate that joint structure significantly influences collision behavior, and accurately recreating it improves the precision of crash test dummy collision behavior analysis using PC-Crash.
Usui, MasatoshiMatsui, YasuhiroHosokawa, NaruyukiTanaka, Yoshinori
Occupant protection has been at the forefront of risk evaluation regarding vehicle crashworthiness design. However, the vehicle is a member of a larger transportation system with varied stakeholders. This article identifies an opportunity for assessing risk in a crash event through emerging safety science paradigms. Conventional Safety I and Safety II frameworks handle well-defined hazards but falter with uncertainty, variability, and emergent behaviors in real crashes. A comprehensive literature review was performed on peer-reviewed research to situate automotive crash safety risk within the Safety III paradigms. The review addresses two questions: (1) How is “risk” defined across the crash safety literature and adjacent safety science domains? and (2) What limitations arise from these definitions in practice? Findings show a dominant probabilistic framing alongside a minority of system-oriented interpretations. Current crash safety practice lacks a coherent, system-level definition
Rye, Patrick J.
Since 2019, sex equity in traffic crashes has been a highly debated topic in vehicle safety, especially following the 2019 study by Forman et al. (1) claiming that female occupants face a 73 percent greater risk of serious injury in frontal crashes compared to male occupants. This was soon followed by a Consumer Reports Article by Keith Barry (2), which attempted to identify underlying factors contributing to the higher risk. These have been embraced by several parties since 2019. Firstly, it was alleged that vehicle design practice over the last four decades considered safety for the male population only and ignored that of the female as evidenced by the exclusive use of the mid-sized male Anthropomorphic Test Devices (ATDs) in Regulatory and Safety Ratings tests and not with an average sized female ATD. The absence of such an ATD for testing of vehicles “set the course for four decades’ worth of car safety design, with deadly consequences” (2). Secondly, although there is a
Prasad, PriyaDalmotas, Dainius J.
Road traffic crashes are a major cause of traumatic brain injury (TBI), particularly among vulnerable road users (VRUs). However, current injury prevention strategies often overlook the heterogeneity of TBI—which include various injury types and severities—leading to an oversimplified approach to evaluating helmets and safety systems in regulations and ratings. To identify priority TBI types and severities in VRUs and to inform targeted prevention strategies, the German In-Depth Accident Study database was analyzed and a pathoanatomic classification system, i.e., Abbreviated Injury Scale, was employed. AIS 2 (moderate) TBIs account for 70-80% of all brain injuries across VRU groups, nearly half of which are concussions. For helmeted cyclists, milder TBIs are at a greater percentage than for unhelmeted cyclists. These findings highlight the need for expanding prevention efforts to include AIS 2+ injuries. Key injury types observed include concussion (with and without loss of
Meng, ShiyangSchindler, RonKleiven, SveinLubbe, Nils
Bird accidental collision with overhead transmission lines poses a threat to the ecology of rare bird populations. This article analyzes the warning measures to prevent birds from accidental collisions at home and abroad. In response to the low efficiency of manual installation and the poor static warning effect in preventing birds from accidental collisions with overhead transmission lines, the visual characteristics of birds are analyzed. A drone-based automatic installation flash-type bird accidental collision warning device is proposed, which includes a fixture, a disc, and a luminous circuit. The fixture can be carried and installed on the overhead line by a drone and can be easily disassembled. The disc adopts eye-catching colors and has a hollow structure to reduce wind resistance load. The luminous circuit includes solar panels, charge and discharge control circuits, flicker control circuits, batteries, and luminous components. The drone suspension warning device test was
Wang, JianWang, XiulongLiu, BinLi, DanyuXu, Xunjian
This article proposes a method for real-time monitoring and rapid alert for guardrail collisions based on Distributed Acoustic Sensing (DAS). The aim is to enhance traffic safety through continuous analysis of vibration signals. To achieve this, a system architecture that combines both hardware and software design has been developed, enabling the handling of the entire process from signal acquisition and decoding to intelligent event recognition and visualization. To improve signal reliability, an adaptive noise reduction algorithm and a multi-level feature extraction method are introduced, enabling accurate differentiation between collision events and environmental disturbances. Tests at various vehicle speeds show that the DAS-based system detects collisions with over 98% accuracy and cuts false alarms by more than 60% compared to traditional video and point-sensor monitoring. It can locate accidents with an average error of 4.2 meters and respond in under 1 second, demonstrating
Sun, Lang
Letter from the Editor-in-Chief
Hardy, Warren N.
Letter from the Guest Editor
Tylko, Suzanne
Research Question/Methods The study examined abdominal injuries of 87 belted occupants in CIREN frontal crashes for sex-based differences in abdominal injury patterns. It introduced a more anatomically detailed method for identifying injury locations in an abdominal-pelvic region that includes skeletal structures. The study introduces and applies a novel Abdominal New Injury Severity Score (AbNISS) to address limitations of traditional AIS coding in capturing sex-based differences in injury patterns. The operative reports/EDR/imaging data in CIREN cases enabled identification of sex-specific crash outcomes. The dominant analytical motif is Bertrand Russell’s knowledge by acquaintance and definite descriptions. Results Females had a higher rate of moderate to severe abdominal injuries than males: Only females sustained AIS 5 injuries, lumbar Chance fractures, posterior pelvic arch injuries, and more AIS 2, 3, and 4 injuries, with more injuries in superior-mid, left-superior, and medial
Halloway, DaleCurry, WilliamSomasundaram, KarthikPintar, Frank
Subaru has developed vehicle-based Injury Severity Predictions (ISP) models using data from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) covering calendar years 1999–2015, for integration into Advanced Automatic Collision Notification (AACN) systems. This study evaluates the accuracy of these ISP models by comparing predictions derived from Subaru vehicle telemetry with actual Injury Severity Scores (ISS) of transported occupants. Two crash databases were utilized: Subaru Telematics Assisted Accident Research (STAAR) data for calendar years 2021–2024, which includes Automatic Collision Notification (ACN) data, police reports, emergency medical services (EMS), and medical records from the medical centers across Michigan; and the Fatality Analysis Reporting System (FARS) data for calendar years 2021–2023, matched with ACN data to supplement serious injury cases. ISS values were obtained from medical records in STAAR, while fatal cases in FARS were
Ejima, SusumuZhang, PengCunningham, KristenWang, Stewart
This study aims to explore and evaluate the effect of various foot positions on the kinematic and kinetic response of the lower extremity during frontal crashes using a realistic vehicle interior. Frontal impact sled tests were performed with the Test Device for Human Occupant Restraint, 50th-percentile Male (THOR-50M) and Test Device for Human Occupant Restraint, 5th-percentile Female (THOR-05F) anthropometric test device (ATD) in the driver’s seat of a midsize SUV testing buck (with realistic interior components including an instrument panel with steering wheel and steering wheel airbag, seat, three-point seat belt with pretensioner and force-limiter, accelerator pedal, brake pedal, knee airbag, and seat belt retractor pretensioner). Six sled tests were performed in two principal directions of force (PDOF) [three each in frontal (0°) and oblique (−20°) configurations]. The right foot was positioned on the accelerator pedal, fully on the brake, and half on the brake. A single test was
Noss, JuniorDonlon, John-PaulMorris, AnnaSamier, GermainPark, JosephForman, Jason
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
Asanuma, HiroyukiGunji, YasuakiMori, FumieNagashima, Akiko
Objective: This study investigated injury outcomes and body kinematics in obese occupants exposed to frontal impacts while seated in reclined postures. With increasing interest in non-traditional seating configurations and a growing population of obese vehicle occupants, the objective was to evaluate how seat stiffness and restraint features influence injury patterns and whole-body excursions. Methods: Nine obese post-mortem human surrogates (PMHS; mean age: 64 years, stature: 1.70 m, body mass: 102 kg, BMI: 35 kg/m2) were tested under frontal impact conditions simulating a delta-V of 50 kph. All specimens were seated on a spring-controlled seat with a 45° reclined seatback and restrained by a three-point belt system with pretensioner and load limiter. Three configurations were evaluated: (1) stiffer seat, (2) softer seat, and (3) stiffer seat with a knee bolster 100 mm from the knees. Each subject underwent one test. Whole-body kinematics were captured using a VICON motion analysis
Somasundaram, KarthikYoganandan, NarayanPintar, Frank
Currently, adult anthropomorphic test devices used in regulatory and consumer information crash testing in the United States are targeted to represent a small female (5th percentile) and an average male (50th percentile). The anthropometry determined previously might not represent the current population, or as investigated in the current study, those that are at least moderately injured during a motor vehicle crash. The objective of this study was to use field data to determine if the current frontal anthropomorphic test devices are representative. Data from the National Automotive Sampling System–Crashworthiness Data System (2010-2015) and Crash Investigation Sampling System (2017–2023) were queried for sex, age, size, and injury information for front seat occupants in frontal crashes. Additional datasets used were from the National Trauma Data Bank and the Centers for Disease Control and Prevention. According to field data, the most frequently injured female and male is approximately
McNeil, ElizabethAtwood, JonathanRudd, RodneyCraig, Matthew
This research examined the performance of SAE Level 2 (L2) advanced driver assistance systems (ADAS) in crash-imminent scenarios (CIS), with particular attention to how vehicle configuration like body style and powertrain (internal combustion engine, plug-in hybrid, electric vehicle) influences vehicle system performance. The objectives were to (1) identify CIS relevant to L2-equipped vehicles using crash databases and naturalistic driving studies (NDSs), (2) develop scenario-based test procedures and test matrices, and (3) evaluate system and vehicle responses across configurations and conditions. Multiple crash data sources were analyzed, including NHTSA’s Standing General Order dataset of L2-related crashes, the Fatality Analysis Reporting System, the Crash Report Sampling System, and NDS data from the Second Strategic Highway Research Program and the Virginia Tech Transportation Institute L2 NDS. Coded variable analyses from the datasets identified three common CIS: lane and road
Beale, GregoryKefauver, KevinVenegas, MichaelLi, EricChen, JayHuggins, StevenGuduri, BalachandarLlaneras, Eddy
The aims of this study were to investigate the kinematics of child anthropomorphic test devices in a large sample of rear-facing child restraint system installations and the effects of anti-rebound features and load legs on the kinematics of rear-facing child anthropomorphic test devices. The test matrix included a general sample of 70 rear-facing child restraint system installations to observe trends in frontal crash tests; 14 full-scale crash tests with paired comparisons to investigate the effect of anti-rebound features; and five paired comparisons of rear-facing child restraint systems installed with and without a load leg. The paired t-test was used to determine the statistical significance of differences in kinematic responses. In the general sample, 84% of anthropomorphic test devices in infant seats with the base in outboard seats interacted with the first-row seat. In 52% of tests, the anthropomorphic test device head directly contacted the front seatback. Head accelerations
Tylko, SuzanneTang, Kathy
Previous rear-facing post-mortem human subject (PMHS) studies utilizing a reinforced seat have prompted questions as to whether the seat could have been a contributing factor to the severe rib and pelvis injuries observed in those experiments. In response, a recent PMHS study used an unreinforced seat in a similar experiment, which was expected to mitigate severe injuries by dissipating energy from seatback deformations. However, the PMHS tested in the unreinforced seat sustained even more severe rib fracture numbers than in the reinforced seat. No studies have investigated how additional variables (i.e., countermeasures) may influence rib fractures in high-speed rear-facing frontal impacts (HSRFFI). Therefore, this study aimed to explore the effect of an airbag-equipped seat (AES) on male PMHS responses and injuries. Rear-facing sled tests were conducted using five mid-size male PMHS seated in the AES at ΔV of 56 km/h: PMHS1 with no airbag as a baseline, PMHS2 with a seatback airbag
Kang, Yun-SeokDeWitt, TimothyWensink, TimothyMarcallini, AngeloJung, Yong HyunLee, Dong GilHarm, Jae JunKo, SeokhoonHunter, RandeeAgnew, Amanda M.
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
Matsui, YasuhiroOikawa, Shoko
This study provides an updated characterization of real-world frontal crash types—considering overlap and obliquity—based on their overall frequency and associated injury outcomes. The results of this study will support an evaluation of how well NHTSA’s frontal oblique crash test condition addresses the current population of serious frontal crashes, as compared to frontal test modes in existing crashworthiness programs. U.S. field crash data from 2017 to 2023 were analyzed to classify frontal crashes by coded damage characteristics. Oblique frontal crashes were defined as those with principal direction of force between 10°–40° and 320°–350°. Non-ejected belted first and second row occupants in model year 2000 and newer passenger vehicles absent a rollover event were included. Occupants were stratified by sex, age, and body mass index, and injury outcomes based on moderate, serious, and fatal thresholds were analyzed across crash configurations. Among the belted first row occupants
Rudd, Rodney W.
The objective of this study was to investigate occupant injury patterns and predictors in rear-impact crashes using recent US field data. Cases were queried from the Crash Investigation Sampling System (CISS, 2017–2023) and the Crash Injury Research and Engineering Network (CIREN, 2017–2024), yielding 1923 front-row outboard occupants from 1533 crashes. Crash documentation and vehicle photographs were manually reviewed to classify seatback deformation magnitude and secondary impact severity. Multivariable logistic regression models estimated associations between occupant, vehicle, and crash characteristics and Abbreviated Injury Scale (AIS) ≥ 2 and AIS ≥ 3 injury outcomes across body regions. Sensitivity analyses included CISS-only, weighted, single-event, and interaction models. Thoracic injuries were further subdivided into skeletal and cardiopulmonary categories. Findings reflect associations within the pooled CISS + CIREN analytic sample rather than nationally representative injury
Lockerby, JackRudd, Rodney
This study investigated how vehicle front-end geometry, impact speed, and vehicle category influence injury risk to a midsize male pedestrian. Eighty-one generic vehicle (GV) models representing sedans, sport utility vehicles (SUVs), pickup trucks, and minivans sold in the United States were developed by morphing three base models using an automated pipeline. Front-end parameters that were varied included ground clearance (GC), bumper height (BH), hood leading-edge (HLE) height, hood length (HL), bumper lead angle (BLA), hood angle (HA), and windshield angle (WSA). Each vehicle impacted the Global Human Body Models Consortium 50th percentile male simplified pedestrian (GHBMC M50-PS) model at 30, 40, and 50 kph, totaling 243 simulations. Boundary conditions followed the European New Car Assessment Program (Euro NCAP) pedestrian test protocol. Thirty-five injury metrics were extracted across the head, neck, thorax, abdomen, pelvis, and lower extremities. Linear mixed-effects regression
Poveda, LuisMiller, Logan E.Edwards, Colin C.Pollock, MadelineArmstrong, William M.Hsu, Fang-ChiGayzik, Scott F.Weaver, Ashley A.Stitzel, Joel D.Devane, Karan S.
The objective of this study is to use parametric human body models (HBMs) to understand how geometric variability among individuals who have the same sex, stature, and body weight may affect the impact responses and injury outcomes, using midsize male and midsize female populations as representative cases. Methods were developed to quantify skeletal and external body surface variations using principal component analysis, regression, and residual error analysis. Based on this analysis, nine midsize male and nine midsize female geometric models were created, focusing on ribcage and pelvis variations, which account for most of the observed variability. These geometries were then applied to morph the simplified Global Human Body Model Consortium (GHBMC) midsize male model, producing 18 distinct HBMs. Each morphed HBM was subjected to nine impact scenarios, resulting in a total of 162 simulations to assess the effects of geometric variability. Substantial geometric variation was observed in
Hu, JingwenLin, Yang-ShenBoyle, KyleKhandare, SujataBonifas, AnneReed, Matthew P.Hasija, Vikas
Traffic collision reconstruction traditionally relies on human expertise and, when performed properly, can be incredibly accurate. However, attempting to perform pre-crash reconstruction, i.e., reconstructing the driver and vehicle behaviors that preceded the actual crash, poses significantly more challenges. This study develops a multi-agent artificial intelligence (AI) framework that reconstructs pre-crash scenarios and infers vehicle behaviors from fragmented collision data. We present a two-phase collaborative framework combining reconstruction and reasoning phases. The system processes 277 rear-end lead vehicle deceleration (LVD) collisions from the Crash Investigation Sampling System (CISS; 2017–2022), integrating textual crash reports, structured tabular data, and visual scene diagrams. Phase I generates natural language crash reconstructions from multimodal inputs. Phase II performs in-depth crash reasoning by combining these reconstructions with the temporal event data
Xu, GeruiChen, BoyouGuo, HuizhongLeBlanc, DaveKusari, ArpanYarbasi, EfeAhmed, AnannaSun, ZhaonanBao, Shan
As a consequence of the introduction of mathematical human body models (HBMs) in consumer information programs, there is an increased need for reliable methods that can demonstrate and build trust in the capability of HBMs to predict human response and injury risk in crashes. Therefore, a framework for validation of strain-based injury prediction is proposed. The framework comprises stepwise validation with the final step to validate the utility of risk predictions by means of the area under the curve (AUC) combined with Brier scores. SAFER HBM V11.1.0 previously validated at component and body part levels was selected for the demonstration of the final step of the framework to validate the capability to predict fracture risk in frontal, oblique, and lateral loading. For frontal loading, five postmortem human surrogate (PMHS) test series with 43 PMHS (age range: 19–88 years) were reconstructed. The predicted rib fracture risk for 2+ and 3+ fractured ribs was compared to the number of
Pipkorn, BengtNiranjan Poojary, YashOsth, JonasLarsson, Karl-JohanIraeus, Johan
This study investigated sex-specific differences in thoracic injury prevalence, causation, and rib fracture patterns among seriously injured occupants in frontal motor vehicle collisions. Crash Injury Research and Engineering Network (CIREN) data from 2005 to 2022 included 793 front-seat occupants aged 16 years and older with Abbreviated Injury Scale 2+ thorax injury, representing 1802 thoracic injuries. Injuries were grouped as rib fracture, sternum fracture, hemo/pneumothorax, lung injury, heart injury, and other. A weighted scoring system captured contributions of involved physical components to each injury. Logistic and linear regression with generalized estimating equations assessed sex associations with injury presence and causation. Two models were estimated: a comprehensively adjusted model including demographic, crash, vehicle, restraint, and airbag deployment, and a simplified model adjusting for age, body mass index, delta-V, and occupant role. Among occupants with AIS 2
Armstrong, WilliamDevane, KaranHsu, Fang-ChiHeilmann, NinaSink, JoelMiller, Anna N.Kiani, BahramMartin, R. ShaynStitzel, Joel D.Weaver, Ashley
Objective The objective of this study was to examine the Large Omnidirectional Child (LODC) anthropomorphic test device (ATD) neck and spine responses in reclined seating configurations with and without a backless belt-positioning booster (BPB) in far-side lateral oblique impacts. Methods The LODC was seated on a production passenger seat with an integrated seatbelt and tested in nine lateral oblique impact (80° from frontal) sled tests (31.3 km/h). A condition with a nominal seatback angle (~25°) with a backless BPB and two conditions with reclined seatback angles (~45° and ~60°) with and without a BPB were compared. Each condition was repeated, except for the 60° without BPB. Peak upper neck tension force and lateral moment, T1, T6, and T12 lateral rotation, lumbar axial and lateral shear forces, and lumbar axial moment (Mz) were extracted. Results With noBPB, upper neck tension (45° noBPB: 2.0 ± 0.1 kN; 60° noBPB: 1.8 kN) and lateral moment (45° noBPB: 31.7 ± 2.3 Nm; 60° noBPB: 29.2
Graci, ValentinaHumm, JohnHauschild, Hans
Roadway departures remain a major cause of crashes, injuries, and fatalities on U.S. roads. Technologies such as lane keeping assist (LKA) and lane centering assist (LCA) can help mitigate these crashes, but their development involves extensive characterization of the parameter space in which they operate. Lane and road departures (LDs/RDs) and lane changes (LCs) must be systematically described and quantified to distinguish kinematic features, identify contributing factors, and benchmark system influence on lateral control. This study developed a unified pipeline to mine over 36 million miles of naturalistic driving study (NDS) data collected from more than 3800 participants. The pipeline integrates various types of signals to detect roadway boundary crossings, classify LKA-relevant scenarios, and extract roadway, driver, environmental, and assistance-related parameters. Lane keeping epochs with and without LKA were also extracted to quantify system influence on lateral control. In
Ali, GibranTerranova, PaoloWilliams, VickiHolley, DustinSaffy, JoshuaAntona-Makoshi, JacoboKefauver, KevinShull, EmilyLi, EricVenegas, Michael
Using a subset of the Transport Canada dataset of rearward-facing CRS in full-frontal rigid barrier vehicle tests, the aim of the current study was to evaluate CRS and/or ATD head contact with the front-row seatback and categorize the contribution to the peak ATD head acceleration. For 33 cases of ATDs seated in rearward-facing CRS models installed in the second-row outboard seats across 19 vehicle tests, high-speed video footage was analyzed to identify instances and timings of CRS and/or ATD head contact with the front-row seatback. The timing of contact was compared to the ATD head acceleration time history to identify instances of “contributory contact” with the front-row seatback, which was defined as contact occurring before the ATD head acceleration was within 10 g of the peak. ATD contributory contact cases involved both the ATD head and CRS contacting the front-row seat, whereas CRS contributory contact cases involved only the CRS, but not the ATD head, contacting the front
Patton, Declan A.Tang, KathyTylko, SuzanneArbogast, Kristy B.
Researchers recently helped Skydio, the leading U.S. drone manufacturer, demonstrate compliance to the Federal Aviation Administration's rules for safe flights over people and vehicles. Virginia Polytechnic Institute and State University, Blacksburg, VA Operators using a drone from the leading manufacturer in the U.S. can now conduct missions over people and vehicles much easier and with even greater confidence in their safety. In January, the Federal Aviation Administration (FAA) accepted a declaration of compliance for such flights for the parachute-equipped Skydio X10 drone from Skydio, a San Mateo, California-based company that supplies its drones to customers in public safety, utilities, and national security. The acceptance came as the result of working with Virginia Tech's Mid-Atlantic Aviation Partnership (MAAP) and Center for Injury Biomechanics to complete their FAA-approved means of compliance testing.
Documenting and mapping using three-dimensional (3D) technologies have become essential in crime- and crash-scene investigations in recent years. Traditionally, this has been accomplished using terrestrial laser scanners (TLS), which often come with significant upfront costs. In contrast, Recon-3D, launched in 2022, leverages the capabilities of Apple’s light detection and ranging (LiDAR) sensor, available in Pro and Pro Max models since 2020. This study aims to evaluate the relative accuracy of documenting vehicles in both pre- and post-collision conditions using these technologies. A deviation analysis was conducted utilizing CloudCompare software to compare point cloud data collected from the Leica RTC360 laser scanner with that obtained from Recon-3D for 7 vehicles in a pre- and post-impact condition for a total of n = 14 vehicles. At the 1, 2, and 3 cm deviation thresholds, the average percent of points which fell below each threshold level for all vehicles was 66%, 91%, and 97
Lim, JihwaLiscio, Eugene
Enhancing child occupant protection requires a clear understanding of how seatbelt restraint parameters influence crash injury metrics. Real-world vehicles mostly include pretensioner and load limiter technologies to mitigate injuries, but rear seat restraints often do not include these. The FMVSS No. 213 test bench closely represents current restraint systems but does not involve such active vehicle restraint features. This study explores the response of the Large Omnidirectional Child ATD to evaluate potential injury mitigation under FMVSS No. 213 frontal sled test conditions. A simulation-based full factorial design was implemented in LS-DYNA to vary pretensioner retraction, retractor load-limiting thresholds, and webbing payout, with injury measures including head acceleration, head excursion, chest compression, and abdominal pressure twin sensors (APTS). Statistical evaluation using analysis of variance (ANOVA) and Tukey-Kramer post-hoc tests quantified main and interaction
Khattak, Mohid MuneebBendig, ColleenLouden, AllisonNoll, Scott
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
Onishi, KojiWang, KewangUno, ErikoIchikawa, KojiTanase, NoboruAndo, Takahiro
Reliable off-road autonomy requires operational constraints so that behavior stays predictable and safe when soil strength is uncertain. This paper presents a runtime assurance safety monitor that collaborates with any planner and uses a Bekker-based cost model with bounded uncertainty. The monitor builds an upper confidence traversal cost from a lightweight pressure sinkage model identified in field tests and checks each planned motion against two limits: maximum sinkage and rollover margin. If the risk of crossing either limit is too high, the monitor switches to a certified fallback that reduces vehicle speed, increases standoff from soft ground, or stops on firmer soil. This separation lets the planner focus on efficiency while the monitor keeps the vehicle within clear safety limits on board. Wheel geometry, wheel load estimate, and a soil raster serve as inputs, which tie safety directly to vehicle design and let the monitor set clear limits on speed, curvature, and stopping at
Naik, AkshayNorris, WilliamSreenivas, Ramavarapu S.Soylemezoglu, AhmetNottage, Dustin S.Patterson, Albert
The effect of tire tread depth on the deceleration performance of anti-lock brake systems (ABS) in newer vehicles is not well studied. A single sport-utility vehicle (SUV) was used to perform a series of 216 ABS-engaged braking tests on dry and wet asphalt and concrete surfaces using six sets of four tires with tread depths varying from 0.8 mm (1/32″) to 7.1 mm (9/32″). Vehicle speed and deceleration as a function of time were calculated from 5th-wheel displacement data sampled at 200 Hz. Braking tests were initially conducted on a dry surface, after which a water truck distributed water onto the road to create a wet condition and additional tests of each tire set were conducted. Overall, average deceleration levels did not vary significantly across the tires sets with tread depths from 7.1 mm (9/32″) down to 2.4 mm (3/32″) for both road surfaces in both dry and wet conditions. Compared to the deceleration levels at these larger tread depths, dry deceleration levels were greater for
Miller, IanKing, DavidSiegmund, Gunter P.
Avoiding and mitigating any potential collision is dependent on (1) road user ability to avoid entering into a conflict (conflict avoidance effect) and (2) road user response should a conflict be entered (collision avoidance effect). This study examined the collision avoidance effect of the Waymo Driver, a currently deployed SAE level 4 automated driving system (ADS), using a human behavior reference model, designed to be representative of a human driver that is non-impaired, with eyes on the conflict (NIEON). Reliable performance benchmarking methodologies for assessing ADS performance are an essential component of determining system readiness. This consistently performing, always-attentive driver does not exist in the human population. Counterfactual simulations were run on responder collision scenarios based on reconstructions from a 10-year period of human fatal crashes from the Operational Design Domain of the Waymo ADS in Chandler, Arizona. Of 16 simulated conflicts entered, 12
Scanlon, John M.Kusano, Kristofer D.Engstrom, JohanVictor, Trent
The timing of video recordings, along with the spatial positioning of objects, is a fundamental parameter for calculating the speed time history. If the task involves determining the average speed of an object moving at approximately constant speed, it may be acceptable to average the speed over several to a dozen frames, using the fps (frames per second) parameter as the basic time unit.. However, if the objective is to compute speed from individual frames, the reliability of the timing becomes crucial. Without access to DVR hardware documentation, proprietary algorithms, or software – and considering the frequent hardware modifications and software updates - the most effective way to solve the problem is through a reverse-engineering approach. This study discusses several aspects of timing analysis, including: (1) making a test recording of a calibrated LED lightboard; (2) analyzing the relationship between the lightboard time and the presentation time stamp (pts) extracted from the
Wach, Wojciech
The braking performance of a vehicle at varying levels of road wetness is an important factor in collision reconstruction. Here we quantify the deceleration levels of two modern vehicles equipped with antilock brake systems (ABS) on a wetted asphalt surface with a high proportion of exposed, large-sized aggregates as the road naturally dried over time. We also compare our current results to prior tests on asphalt with a small proportion of small-sized aggregate. Two ABS-equipped vehicles were maximally braked on an asphalt road surface as the road naturally transitioned from a saturated wet state to a completely dry state. Road wetness was visually categorized from photographs taken during testing. Overall, we found that deceleration levels on wet asphalt were significantly less than deceleration levels on dry asphalt (average dry: 0.902g and 0.962g; average wet: 0.787g and 0.818g for the two vehicles). Within the wetness categories we used, there was either no significant difference
Ahrens, MatthewArnold, NikolasMiller, IanSiegmund, Gunter P.
In order to determine the on-board EDR data recording characteristics of a GM vehicle, a 2023 GMC Sierra Denali was tested in several Pedestrian Automatic Emergency Braking (P-AEB) scenarios. Using a variety of test tools, including the STRIDE robotic platform and its onboard data systems, a GPS/IMU installed in the vehicle, and several camera units, the vehicle was put into collision imminent scenarios in which the crash avoidance systems were actuated. The flags in the EDR data, the order in which EDR events were written, and the correlation between the EDR and data recorded by the aforementioned external acquisition systems were examined for each test case. Testing was done in both forward and reverse scenarios and at low speeds only. These results provide a picture of the current state of the additional data available in current EDRs installed on GM vehicles equipped with P-AEB capability, as well as an insight into the accuracy and meaning of that data which should prove
Bartholomew, MeredithArnett, MichaelGuenther, Dennis
This study analyzed driver behavior in Turn-In-Path (TIP) scenarios using the Second Strategic Highway Research Program (SHRP2) naturalistic driving dataset. A total of 167 real-world incidents, including both crashes and near-crashes, were examined to evaluate human driver perception-response times (PRT) and avoidance behaviors when an intruding vehicle (the principal other vehicle, or POV) turns into the path of a straight-moving subject vehicle (SV). The combined analysis includes TIP events involving POVs turning from intersecting roads to either cross or merge into the SV’s lane and continues in the direction of the SV. Each event was reviewed to identify the driver behavior in an emergency response event, with measurements taken from video and telematics data. Response time was measured across two different starting points. Key variables included time to conflict, POV behavior, SV driver engagement in secondary tasks, and environmental factors such as lighting and roadway
Dinakar, SwaroopMuttart, JeffreyMaloney, TimothyAdhikari, Bikram
The phenomenon of bicycle pitch-over is simple in concept, yet determining threshold criteria for pitch-over has yet to be well established, particularly with respect to determining whether or not a bicycle’s front wheel will roll over a particular obstacle or not. Two prior SAE papers have laid out two different analytical approaches to predict this threshold – the Moment-Inversion and Brach Pitch-Over Threshold models - and this paper proposes a modification to the Moment-Inversion model to account for tire deflection. Testing began by measuring the center of gravity locations and moments of inertia for a bicycle with weights and training wheels and for a test rider on a bicycle and tricycle. These physical measurements were used to calculate the predicted pitch-over height for each system for each model. The test systems were then ridden over a series of progressively taller square edge obstacles until they transitioned from rolling over to stopping or pitching over. From this
Sweet, David MichaelO'Brien, NathanBretting, Gerald
This paper presents the multidisciplinary development of a hybrid automotive hood manufactured using double-shot injection molding with overmolded brackets. Conventional steel and aluminum hoods, while structurally reliable, pose challenges in terms of weight reduction, pedestrian head protection, and manufacturing cost. Composite and thermoplastic alternatives supported by computational analysis and advanced molding processes provide opportunities to address these challenges. Finite element analysis (FEA) was employed to evaluate torsional and bending stiffness, locking load, and crashworthiness, while pedestrian headform simulations following ECE R127 and EEVC WG17 guidelines were conducted to assess compliance with safety regulations. Adhesion and bonding strength of overmolded polymer–polymer interfaces were studied to validate manufacturing feasibility. Results confirm that hybrid hoods fabricated using multi-material double-shot molding can achieve weight reductions of up to 30
Ganesan, KarthikeyanSeok, Sang HoJo, Hyoung Han
Variation studies are an important part of the product development process. They help to understand and estimate real-world deviation from nominal design parameters, optimize designs for robustness, reliability, and cost-efficiency. CAE and Virtual tools enable us to simulate variation types and capture the full bandwidth of actual field performance- rather than the validation from a limited number of physical tests. In this study, the effects of various factors on vehicle performance during low-speed impacts, utilizing a Design of Experiments (DOE) approach have been investigated through virtual simulation. Low-speed impacts, typically defined as collisions occurring at speeds less than 2.5 mph, are critical for understanding vehicle insurability and compliance with regulatory standards. The factors examined include vehicle impactor position, impact speed, angle of collision, part thickness variation, material property variation. The DOE methodology allowed for a systematic analysis
Suravaram, Raghu Mohan ReddyIslam, ABM IftekharulLarson, JohnTehrani, BabakKoch, LisaMathur, Mohit Sain
Autonomous vehicles may attract more passengers to recline their seat for comfort. However, under severe rear-end crashes and large reclining angle, the backward inertia could completely throw occupant out of seat. Even if the occupant body can be restrained by seatbelt, the occupant’s head could slide out of the head restraint area. Any of these situations may cause severe injuries. To address this safety concern, we developed a sliding seat system designed to enhance occupant retention. Activated by impact inertia of rear-end collision, the system allows the seat sliding backward along its track in a controlled manner, and the sliding stroke is accompanied by a restraint force and absorbs some amount of kinetic energy during the sliding. Thus, occupant retention can be enhanced, and injury risks of head and neck can be reduced. To demonstrate this concept, we built a MADYMO model and conducted a parametric analysis. The model includes a 50th percentile human model, a vehicle seat
Dai, RuiZhou, QingPuyuan, TanShen, Wenxuan
Five sled tests were performed with a Hybrid III (H-III) 10-year-old child sized Anthropomorphic Test Device (ATD) positioned in the 2nd row left seat of a three row 2006 Sport Utility Vehicle (SUV). A HYGE Sled buck was positioned to represent/replicate a side impact collision to the passenger (right) side of the SUV, with a Principal Direction of Force (PDOF) of 60 degrees, resulting in a far side side-impact for the ATD. Of the 5 tests performed, three of the five tests were performed with a delta-V of 17 mph, and two of the tests at a delta-V of 24 mph. Of the 17 mph tests, one test was performed with a properly restrained ATD, and two tests performed with improper restraint positioning. Both of the 24 mph tests were performed with improper restraint positioning, effectively identical to the two 17 mph delta-V tests. The two improper restraint use tests (at both 17 and 24 mph delta-V) included two different improper restraint scenarios. The first scenario of improper restraint
Luepke, PeterHewett, NatalieBetts, KevinVan Arsdell, WilliamWeber, PaulStankewich, CharlesMiller, GregoryWatson, RichardSochor, Mark
In a few extreme customer abuse load cases such as curb impact and potholes, automotive structures see non-linear (plastic) deformations as well as large rigid body motion. The load cases can be simulated by a few tools: crash analysis tools such as LS-Dyna, non-linear structure analysis tools, or multi-body dynamics (MBD) analysis tools like Ansys Motion. The three simulation tools have pros and cons, respectively. In this study, a curb impact simulation was performed using the multi-body dynamic approach with nonlinear structural analysis capabilities included in Ansys Motion. The tool demonstrated the simulation was completed faster than other MBD tools due to smartly recycling the system Jacobian matrix when structural deformation was not significant. The results were compared with structural analysis and correlated reasonably well. The post-impact suspension alignment changes can also be simulated for reviewing design requirements. This approach proposes a new way to simulate
Hong, Hyung-JooKim, Wangoo
Crashes involving passenger vehicles increasingly include vehicles equipped with infotainment systems that are unsupported by commercial vehicle system forensics hardware and software. Examiners facing these systems must overcome challenges in acquiring and analyzing user data, requiring an understanding of both digital forensics principles and the proprietary characteristics of the modules. This paper presents a methodology for acquiring data from previously unsupported Lexus infotainment modules, including techniques to bypass CMD42 security locks on SD cards and extract data. Once acquired, the paper outlines methods for analyzing user data through data carving techniques, enabling recovery of information from binary images even when the full file system cannot be reconstructed. Emphasis is placed on maintaining the integrity of the evidence and validating findings through controlled testing. These validation procedures ensure that the recovered information is both accurate and
Burgess, Shanon
The design trend among analog speedometer and tachometer instruments in recent decades has been toward stepper motor drives. If power is interrupted during a traffic crash, such gauges often do not return to a zero reading. Speedometers and tachometers displaying residual readings after a crash have been observed with increasing frequency in recent years. In conducting a crash reconstruction, a question often arises as to whether such a residual reading corresponds to the indicated vehicle speed at the time of impact in the crash. Prior publications in this area have included a variety of crash tests under a wide range of relatively uncontrolled conditions. The present investigation evaluated a total of nine instrument clusters with a range of static torque required to move the needles when unpowered. The clusters were mounted on a HYGETM crash simulation sled and subjected to consistent impulses at orientations representing frontal, rear, left and right lateral, and left and right
Walker, JamesDuran, AmandaKent, StevenBarnes, DanielOsterhout, AaronClayton, Aidan
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