Browse Topic: Accident reconstruction

Items (829)

Land Use Compatibility for Vertiports: A Comprehensive Approach

F-0081-2025-0077

5/20/2025

This study provides a comprehensive framework for establishing land use compatibility guidelines specific to vertiports serving electric Vertical Takeoff and Landing (eVTOL) aircraft within urban settings. Recognizing critical gaps in current regulatory standards, the research systematically integrates analyses of accident risk, noise propagation, and aerodynamic impacts—including downwash and outwash—to delineate compatibility zones around vertiports. Employing an artificial intelligence (AI) augmented system, the study conducted safety and hazard assessments, various quantitative analyses, and simulations to identify spatial constructs of operational risks and environmental impacts. Results indicated significant discrepancies between existing aviation infrastructure guidelines and the unique operational characteristics of eVTOLs, necessitating revised zoning parameters. The proposed multi-tiered safety zoning framework provides precise, evidencebased recommendations for urban planners, enhancing safety, minimizing noise impacts, and ensuring environmental sustainability. Ultimately, this research offers policymakers and stakeholders practical tools for integrating advanced air mobility infrastructure safely into complex urban landscapes.

Ison, David

Probabilistic Trajectory Analysis of Debris Items for Crash Investigation

F-0080-2024-1408

5/7/2024

Air safety investigators must seek out all available sources of evidence from an aircraft crash incident in order to make informed root cause determinations. This is especially important when the incident aircraft was not equipped with flight and voice data recorders. Previous investigations have utilized trajectory analysis methods as a technique to determine where debris items may be found on the ground after an in-flight breakup. Alternatively, if the ground placement of debris items is known, then the airspeed and heading of the aircraft may be back-calculated. In this paper, a probabilistic trajectory analysis is developed to infer crash debris initial conditions at time of impact. Digital methods including computational fluid dynamics have been employed to calculate debris item aerodynamic coefficients and probabilistic sampling techniques to determine a likely range of initial angles and initial velocities. Finally, two example cases are presented to illustrate application of the technique and its utility for design making with respect to crash investigation.

Coleman, Dustin, Casanova, Javier, Barrett, Arild, Bowles, Patrick

Title updates jms

SAE-PP-004008/13/2021

Abstract

Jackson, Alyssa

Intelligent Voice Activated Drone(s) for in-Vehicle Services and Real-Time Predictions

2021-01-00634/6/2021

Today, commercially available drones have limited use-cases in the rapidly evolving community. However, with advances in drone and software technology, it is possible to utilize these aerial machines to solve problems in a variety of industries such as mining, medical, construction, and law enforcement. For example, in order to reduce time of investigation, Indiana State Police are currently utilizing ad-hoc commercial drones to reconstruct crash scenes for insurance and legal purposes. In this paper, we illustrate how to effectively integrate drones for in-vehicle services and real-time prediction for automotive applications. In order to accomplish this, we first integrate simpler controls such as voice-commands to control the drone from the vehicle. Next, we build smart prediction software that monitors vehicle behavior and reacts in real-time to collisions. Furthermore, we employ object recognition techniques through In-Vehicle Infotainment (IVI) systems to identify the surroundings based on inputs from drone-mounted camera sensors. Consequently, we implement object identification and smart maneuver of the drone in relation to the vehicle; as well, employ timely deployment of the drone prior to collision for emergency assistance and crash reconstruction purposes. The goal is to optimize performance and amplify safety and security of the vehicle. The prototype detailed in this paper was tested on a vehicle moving at a speed of 45 mph. The driver of the vehicle can deploy and control the drone using voice commands. The drone follows the vehicle and is in-sync with the vehicle and performs tasks to aid in post-collision assistance and crash reconstruction.

Nithiyanantham, Mayunthan, Sinnapolu, Giribabu

Occupant Restraint System Evaluation - Lateral Rollover System-Level Heavy Trucks

J2426_202103 (Current)

3/1/2021

This SAE Recommended Practice describes the test procedures for conducting simulated dynamic lateral rollover restraint system tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.

Truck Crashworthiness Committee

AVSC Best Practice for Data Collection for Automated Driving System-Dedicated Vehicles (ADS-DVs) to Support Event Analysis

AVSC000042020099/23/2020

As technology and functionality of vehicle systems change, so do data recording needs. In ADS-dedicated vehicles (DV), the ADS perceives the environment and handles vehicle motion control, i.e., the dynamic driving task (DDT), as described in SAE J3016. When an ADS takes the place of a human driver, its sensing, processing, and control systems necessitate new considerations for data recording. Data recording is important to crash reconstruction, system performance investigations, and event analysis. It enables industry-wide improvements in ADS safety. This best practice makes recommendations for the ADS-DV data needed to support: (1) information about what the ADS "saw" and "did" and (2) identify the technology-relevant factors that contributed to the event. The Best Practice for Data Collection for Automated Driving System Dedicated Vehicles (ADS-DVs) to Support Event Analysis makes recommendations for the collection, storage, and retrievability of onboard motor vehicle ADS event data. A list of 39 data elements are recommended for ADS-DVs to collect, including 14 new elements specific to ADS-DVs and 25 elements either previously defined or adapted from legacy standards in data collection.

Automated Vehicle Safety Consortium

Applying Automotive EDR Data to Traffic Crash Reconstruction Virtual Pre-Conference Certification

C20168/7/2020

EDR\'s were first installed in 1994 and are now installed in 99% of new light vehicles sold in the US. In the US EDR’s are not required, but vehicles with EDR’s made after 9/1/2012 must meet minimum standardized content requirements of 49 CFR, Part 563 including speed, throttle, brake on/off and Delta V. Data must be retrievable with a publicly available tool. Only a few manufacturers install EDR’s worldwide currently, but the EU and China are adopting regulations to require them in the next few years. Some manufacturers provide stability control system data far beyond the US regulation that aid in understanding vehicle movement in the 5 seconds prior to the crash. This course will provide the participant with the skills necessary to analyze EDR data that has already been imaged, apply it to crash reconstruction, and reconcile it with calculations using other data sources. The course will enable the participant to analyze current and potential future EDR data set without regard to manufacturer. The class presents the generic analysis step by step, then groups EDRs into manufacturer-specific families and their data limitations, and works case studies that highlight targeted key learning objectives. The student will also learn key points to satisfy court Frye and Daubert requirements for EDR data to be admissible, and suggest methods to present EDR data that will communicate the data understandably to attorneys and lay juries. This course has been approved by the Accreditation Commission for Traffic Accident Reconstruction (ACTAR) for 20 Continuing Education Units (CEUs). Upon completion of this seminar, accredited reconstructionists should mail a copy of their course certificate and the $5 student CEU fee to ACTAR, PO Box 1493, North Platte, NE 69103. By attending this seminar, you will be able to: Describe EDR sensor operation, recording interval and duration, resolution, accuracy, and time latency and articulate the limitations of applying the data to crash analysis Calculate min and max speeds prior to loss of control or braking, and at impact based on the last accurate EDR pre-crash speed data point Evaluate EDR vs. actual ground speed for specific vehicle operational conditions and vehicle equipment modifications Calculate speed at impact and closing speeds by combining EDR Delta V data with normally collected scene and vehicle data such as post crash travel distance, departure angle, drag factor, and vehicle weights Apply data to inline rear end, head on, and angular collisions Reconcile EDR data with other physical evidence and combine to narrow speed ranges Use time-distance and overlay EDR data on scene maps/diagrams to show where critical driving inputs were made vs. inputs required to avoid collisions CEUs

A Study of Driver's Driving Concentration Based on Computer Vision Technology

2020-01-05724/14/2020

Driving safety is an eternal theme of the transportation industry. In recent years, with the rapid growth of car ownership, traffic accidents have become more frequent, and the harm it brings to human society has become increasingly serious. In this context, car safety assisted driving technology has received widespread attention. As an effective means to reduce traffic accidents and reduce accident losses, it has become the research frontier in the field of traffic engineering and represents the trend of future vehicle development. However, there are still many technical problems that need to be solved. With the continuous development of computer vision technology, face detection technology has become more and more mature, and applications have become more and more extensive. This article will use the face detection technology to detect the driver's face, and then analyze the changes in driver's driving focus. Firstly, the problem of detecting the eyes and mouth status of the driver is discussed. The purpose is to capture the driver's long-term closed eyes and yawning and other actions closely related to the dozing behavior. Secondly, the problem of estimating the driver's head posture is studied. The purpose is to capture the abnormal movements of the driver's long bow, head up or frequent nodding. The study consists of three parts: detection of facial feature points, estimation of the head posture based on the feature points, and definition of fatigue characteristics. The experimental results show that the method in this paper is not only easy to operate but also has a high accuracy rate for the detection of driver concentration.

Lin, Guan, Zhan, Zhenfei, Peng, Xiangjun, Xu, Huijie, Fu, Yue, Jiang, Ling

Frequency Domain Analysis of 2-Wheeler Systems

2020-01-04764/14/2020

Most automotive companies validate their vehicle designs by running vehicle on the durability proving grounds. Part fractures and collisions between two components are common failures observed during proven ground testing. Laboratory testing and FEA simulation are used to validate designs in the concept stage as it consumes less time and cost as compared to proven ground testing. The lab testing and simulation process both have their own limitations. It is difficult to incorporate effect of multi-direction input loading (x, y, z) with single direction loading in laboratory testing due to restrictions with electrodynamic shaker testing. However, in simulation, multi direction input can be easily incorporated but often actual vehicle measured test track data is not available in the early design stage. In the present work, Modern methodologies have been employed [ref 1, 2] in frequency domain to validate design in FEA simulation. First, relative random response calculation is performed for calculating the probability of collision between parts of motorcycle rear cowl. Second, multi-channel loading (x, y, z) on the front cowl is used to derive a simple single direction (surrogate) loading which has similar impact in terms of structural response (stress and fatigue). This derived single direction loading can be used efficiently in shaker testing. Third, a standard input load envelope is created in such a way that it includes all set of possible loading scenarios for a motorbike fuel tank assembly. This standard input load can be used at an early stage of design so that it helps in predicting component failure in FEA simulation.

Sethi, Mohit, Sharma, Ashish, Khare, Saharash, Sethi, Mohit, Sharma, Ashish, Khare, Saharash, Bishop, Neil, Kolar, Harsha

Determination of Seatbelt Use Following a Crash

2020-01-06434/14/2020

When investigating a vehicle crash, the issue of seatbelt usage is frequently part of the information needed to perform an occupant kinematics or injury analysis. A physical inspection of the vehicle is the preferred method to investigate seatbelt usage. However, if the vehicle is no longer available, or the condition has changed since the time of the crash, preventing analysis of seatbelt usage by an occupant, the investigators must rely on other available evidence to assess occupant seatbelt usage. This would typically include a review of the police report, scene or early photographs of the vehicle, physical marks on the occupant in medical records and statements from witnesses. More recently, event data recorders (EDR) can provide data regarding seatbelt status for front seat occupants, and occasionally, rear seat occupants. However, the EDR data must have been previously recovered or the vehicle must be available. In cases where the available data is limited or includes only subjective data such as a police report or statements of occupants, some investigators have used the post-crash seatbelt position to determine seatbelt usage at the time of the impact. The theory is if the seatbelt is retracted or stowed post-crash, it was not in use at the time of the collision. The validity of this theory was investigated using EDR data from the NHTSA Crash Investigation Sampling System (CISS) as well as EDR files collected during in-house crash investigations. Photographic documentation of the post-crash seatbelt position was compared to EDR reported seatbelt use to determine if post-crash seatbelt position is reliable in determining seatbelt usage at the time of impact. Additionally, EDR seatbelt usage was compared to police reported seatbelt usage. The analysis of the data in this study found that in a third of the cases where the EDR data indicated the occupant was seatbelted, the seatbelt was found in the stowed or retracted position. Therefore, finding a stowed or retracted seatbelt following a crash is not a reliable means of determining seatbelt use by the occupant at the time of the crash. Additionally, a comparison of EDR data to police reported seatbelt usage revealed that 13 to 25 percent of the occupants reported by the police as seatbelted did not have the seatbelt fastened based on EDR data.

Yannaccone, John R.

Simulation of Curved Road Collision Prevention Warning System of Automobile Based on V2X

2020-01-07074/14/2020

Li, Xuanhe, Wu, Jian, He, Rui, Zhu, Bing, Zhao, Jian, Zhou, Hang

Analysis of Dashcam Video for Determination of Vehicle Speed

2020-01-08774/14/2020

Using dashcam video footage to extract reliable vehicle speed data can be challenging when the only available image stream comes from a camera whose optical parameters are unknown. One means of overcoming such difficulties uses visible landmarks and features within the video frame whose dimensions can be independently measured. While good results have been obtained by others using a Total Station or LiDAR to physically measure locations for such purposes, this approach could prove difficult if a site of interest is inaccessible (e.g. on a busy highway that cannot be shut down) or if relevent features of the target location have changed (e.g. due to construction or even restriping of lanes lines). As an alternative to direct scene measurement, it is proposed that measurement of features visible in overhead satellite images be used to dimension relevant features visible in the video. In this work, videos from individual dashcams and phone-based cameras were used to calculate average vehicle speed by tracking individual features as they pass through and then exit the image frame. Because the features used herein are limited to periodically-occurring markings such as lane lines, average vehicle speed is calculated based solely on distances referenced to these features as well as video frame rate. Although limited in scope, a major advantage of this approach is that it eliminates the need for camera calibration, because only one small patch of the image frame is used for the average speed calculation. In this study, selected video sequences were used to calculate vehicle speed at speeds ranging from 16 - 65 mph, with results corresponding to the vehicle’s speedometer display for all but the lowest frame rates.

Leifer, Jack, Marquez, Alvaro

An Improved Probabilistic Threat Assessment Method for Intelligent Vehicles in Critical Rear-End Situations

2020-01-06984/14/2020

Threat assessment (TA) method is vital in the decision-making process of intelligent vehicles (IVs), especially for ADAS systems. In the research of TA, the probabilistic threat assessment (PTA) method is acting an increasing role, which can reduce the uncertainties of driver’s maneuvers. However, the driver behavior model (DBM) used in present PTA methods was mainly constructed by limited data or simple functions, which is not entirely reasonable and may affect the performance of the TA process. This work aims to utilize crash data extracted from Event Data Recorder (EDR) to establish more accurate DBM and improve the current PTA method in rear-end situations. EDR data with responsive maneuvers were firstly collected, which were then employed to construct the initial DBM (I-DBM) model by using the multivariate Gaussian distribution (MGD) framework. Besides, the model was further subdivided into six parts by two important risk indicators, Time-to-collision (TTC) and velocity. To accurately represent the driver’s maneuvers in critical situations, unresponsive samples were introduced and the I-DBMs were upgraded by the Gaussian mixture model (GMM). The obtained DBMs were employed to sample driver’s evasive behaviors by Monte Carlo Markov Chain (MCMC) method, which generated multiple collision-avoidance trajectories. Finally, we chose the real-world crash case in the SHRP2 dataset to verify the proposed method. Results show that the upgraded DBMs reasonably represented the driver’s evasive maneuvers, and the MCMC method could capture the main features of given GMM distributions. The proposed PTA method can accurately depict the changing trend of dangerous degree and derive the crash probability (CP) at critical point of time. Its effectiveness and real-time performance were verified in the chosen rear-end case. The improved PTA method can be used for real-time TA application and contribute to the development of the decision-making process for ADAS and IVs.

Zhou, Huajian, Zhong, Zhihua, Wang, Xiaowei, Huang, Jin

Prevention of Snow Accretion on Camera Lenses of Autonomous Vehicles

2020-01-01054/14/2020

With the rapid development of artificial intelligence, the autonomous vehicles (AV) have attracted considerable attention in the automotive industry. However, different factors negatively impact the adoption of the AVs, delaying their successful commercialization. Accretion of atmospheric icing, especially wet snow, on AV sensors causes blockage on their lenses, making them prone to lose their sight, in turn, increasing potential chances of accidents. In this study, two different designs are proposed in order to prevent snow accretion on the lenses of AVs via air flow across the lens surface. In both designs, lenses made of plain glass and superhydrophobic coated glass surfaces are tested. While some researchers have shown promise of water repellency on superhydrophobic surfaces, more snow accretion is observed on the superhydrophobic surfaces, when compared to the plain glass lenses. In the experiments, snow is formed using a novel snow gun inside a walk-in cold room connected to a wind tunnel that can reach wind speeds of up to 40 mph. It is observed that the air flow over the lens significantly reduces the accretion of snow on the lens and could maintain the lens clean for up to 20 mph wind velocities. However, at LWC values of approximately 28%, the stickiness of the snowflakes increases, enhancing snow accretion on the lenses and translating to significant loss of sight. The high stickiness of the snowflakes along with high wind speeds leads to increased blockage of the AV lenses.

Mohammadian, Behrouz, Sarayloo, Mehdi, Heil, Jamie, Sojoudi, Hossein, Robertson, Michael, Hong, Haiping, Tran, Tommy, Patil, Sunil, Krishnan, Venkatesh

Optimization of Braking Strategy for Automatic Emergency Braking System in Vehicle-Pedestrian Accidents

07-12-02-00093/23/2020

Braking strategy is the core of the automatic emergency braking (AEB) system. How to make the braking strategy of the AEB system more suitable for real traffic conditions and more acceptable to drivers is a very important research. This article carries out the braking strategy optimization for the AEB system. From the vehicle-pedestrian accidents collected by the National Automobile Accident In-depth Investigation System (NAIS) of Songjiang Station, this article selects typical cases equipped with event data recorder (EDR) and then analyzes the EDR data. On this basis, the strategy for the optimization of the AEB system is formed. The optimized strategy is simulated in the test scenario specified in the European New Car Assessment Programme (Euro-NCAP) and compared with the real vehicle test results. The result illustrates that the optimized braking strategy is more effective to avoid or mitigate collisions.

Qian, Yubin, Yang, Xueyan, Xiao, Lingyun, Zhu, Yican

Influence Analysis of AEB Two-Wheeler on Passenger Car Impact Two-Wheeler Traffic Accidents in China

2020-01-50232/24/2020

AEB two-wheeler system is an active safety technology which developed for avoiding two-wheeler accidents. With a large number of two wheelers, China needs to conduct research and analysis of this system. In this paper, real traffic accident data in China are used to analyze the possible influence of AEB two-wheeler system on traffic accidents. The paper chooses real passenger car impact two wheeler accidents happen in China, and gets the characteristics of data analysis. Then the paper analysis the influence of AEB system using position data when TTC=3s. According to the analysis, the detection range of 90 meters and the detection angle of 45 degrees can improve the recognition rate of day crossing accident by 17.7%, night crossing accident by 21.5% and longitudinal accident by 38.8%. The paper provides effective support for the development and test of AEB two-wheeler system in China. Car-to-two-wheeler accident AEB two-wheeler system Influence of the accident

Xudong, Li, Xiaowei, Lian, Xingchang, Wang

Study on Comprehensive Evaluation Index of Front Collision Hazard of Intelligent Vehicle

2019-01-504411/4/2019

Collision avoidance technology is one of the key areas in the longitudinal safety research of intelligent vehicles. For the research of collision avoidance system, the existing methods usually use the evaluation index based on time interval or braking process to carry out risk assessment. In order to overcome the shortcomings of the formulas for describing the longitudinal hazard degree established in most studies, such as great differences, inconsistent standards and weak normalization, a comprehensive evaluation method for the longitudinal hazard in front-impact scenarios is established. This method takes into account both the analysis of time interval and braking process, and considers the non-linear variation of the longitudinal hazard degree with the real-time distance and speed of two vehicles. It can describe the longitudinal hazard degree of vehicles in dangerous traffic scenarios. Compared with the existing longitudinal hazard assessment methods, the effectiveness and universality of the pre-collision hazard assessment method proposed in this paper are demonstrated.

Jiaxiang, Qin, Zhang, Sumin, Weiwen, Deng, Rui, He

RDS Phrase Lists

J2540/1_201906 (Current)6/11/2019

This SAE Standard provides a table of textual messages meeting the requirements for expressing “Radio Data Systems” (RDS) phrases commonly used in the ITS industry. They can be used both over the RDS subcarrier transmission media as part of a 37-bit long “Group 8a message” as well as being used to provide a common content list of phrases used in a wide number of other media and applications. This document SHALL define the normative index values to be used, extending the CEN established list to provide phrases needed by US practitioners. This standard provides non-normative textual phrases which MAY be used by implementers to ensure intelligible results. This document SHALL follow the formats and rules established in SAE J2540 in the expressions, manipulations, and use of such tables. It should be pointed out that within the rules established by this document a variety of final table are all considered “compliant” with the document, and may vary as fits the needs of implementers.

V2X Core Technical Committee

Reconstruction of 3D Accident Sites Using USGS LiDAR, Aerial Images, and Photogrammetry

2019-01-04234/2/2019

The accident reconstruction community has previously relied upon photographs and site visits to recreate a scene. This method is difficult in instances where the site has changed or is not accessible. In 2017 the United States Geological Survey (USGS) released historical 3D point clouds (LiDAR) allowing for access to digital 3D data without visiting the site. This offers many unique benefits to the reconstruction community including: safety, budget, time, and historical preservation. This paper presents a methodology for collecting this data and using it in conjunction with aerial imagery, and camera matching photogrammetry to create 3D computer models of the scene without a site visit. To determine accuracies achievable using this method, evidence locations solved for using only USGS LiDAR, aerial images and scene photographs (representative of emergency personnel photographs) were compared with known locations documented using total station survey equipment and ground-based 3D laser scanning. The data collected from three different site locations was analyzed, and camera matching photogrammetry was performed independently by 5 different individuals to locate evidence. On average, the resulting evidence for all three test sites was found to be within 3.0 inches (8cm) of known evidence locations with a standard deviation of 1.7 inches (4cm). To further evaluate the quality of the USGS LiDAR, a comparative point cloud analysis of the roadway surfaces was performed. On average, 85% of the USGS LiDAR points were found to be within .5 inches of the ground-based 3D scanning points.

Terpstra, Toby, Dickinson, Jordan, Hashemian, Alireza, Fenton, Stephen

Study on a Method for Evaluating the Safety of the Braking Control Algorithm for Automated Driving System When Following

2019-01-10154/2/2019

The purpose of this study is to develop a method for evaluating the safety of the braking control algorithm for automated driving under mixed traffic flow of automated driving system and vehicles driven by drivers. We consider that the automated driving system should be controlled such that it blends in with mixed traffic. Therefore, in evaluating the safety of braking control for the automated driving system when following, the influence of the automated driving system on the driver of the following vehicle is an important evaluation index. First, we analyzed past traffic accidents in Japan to determine a suitable traffic environment for evaluating the safety of the braking control algorithm for the automated driving system when following. Second, the driver’s braking operations were measured using actual vehicles in this situation. We developed a method of generating sample algorithms of braking control based on the driver’s braking operations. Finally, we developed a method of identifying the most suitable range of parameters of braking control algorithms by evaluating these sample algorithms based on the results of actual experiments. This evaluation method uses a driving simulator. The automated driving system in which the sample algorithm of braking control is installed runs ahead of the vehicle driven by a subject in the driving simulator. The subject evaluates the sense of danger for braking by the automated driving system.

Gokan, Masato, Tanaka, Nobuhisa, Furukawa, Yoshimi, Iwase, Tunetoshi, Hirowatari, Taichi

Uncertainty in Radius Determined by Multi-Point Curve Fits for Use in the Critical Curve Speed Formula

2019-01-04284/2/2019

The critical curve speed formula used for estimating vehicle speed from yaw marks depends on the tire-to-road friction and the mark’s radius of curvature. This paper quantifies uncertainty in the radius when it is determined by fitting a circular arc to three or more points. A Monte Carlo analysis was used to generate points on a circular arc given three parameters: number of points n, arc angle θ, and point measurement error σ. For each iteration, circular fits were performed using three techniques. The results show that uncertainty in radius is reduced for increasing arc length, decreasing point measurement error, and increasing number of points used in the curve fit. Radius uncertainty is linear if the ratio of the standard deviation in point measurement error (σ) to the curve’s middle ordinate (m) is less than 0.1. The ratio σ/m should be less than 0.018 for a radius found using a 3-point circular fit to be within 5% of the actual value 95% of the time. Increasing the number of points used for the fit reduces uncertainty in radius: a 15-point fit reduces the 95% prediction interval width by up to 42%, or allows a shorter yaw mark arc angle with the same uncertainty in radius.

Heinrichs, Bradley, Mithrush, Troy

Two Phase Heavy Truck Acceleration Model

2019-01-04114/2/2019

There have been several papers published over the past 25 years regarding the acceleration of heavy trucks, including different loading conditions, drivetrain configurations, and driving techniques. The papers provide a large data set that measures the speed, distance, and time of the vehicles during acceleration testing and present the data in tabular or graphical formats. Although the data as presented can be useful, it can be challenging to pore over all the data to determine the correct set for a specific application in accident reconstruction. As of this paper’s date of publication, there are approximately eight relevant papers with a total of 268 acceleration tests performed, spanning many years. This paper reviews all the available published literature and summarizes the relevant data in a comprehensive list of accelerations for different heavy truck configurations, which provides a valuable resource to the accident reconstruction field.

Danaher, David, McDonough, Sean, Donaldson, Drew

Residual Injury Situation and Accident Characteristics of Severe Motorcycle Accidents

2019-01-06384/2/2019

The total number of persons severely and fatally injured in road traffic accidents has reduced considerably in recent decades. However, the number of motorcyclists involved in accidents has not reduced to the same extent, and some countries have even recorded an increase. The aim of this study is to analyse the circumstances of motorcycle accidents in Germany involving vehicles with a cubic capacity of over 125 cm3 with particular reference to severely or fatally injured riders. An analysis is to be made of the characteristics and patterns of injuries suffered by the most severely injured motorcyclists and proposals developed for injury prevention. The study included accident data from 464 motorcycle accidents collected in Hanover and Dresden between 2010 and 2015 by an academic research team in the course of the GIDAS project (German In-Depth Accident Study). This data represents a statistically representative sample from real accidents occurring in Germany. The analysis of the current injury situation shows that motorcyclists are often severely injured, i.e. suffered injuries of grade MAIS 3+ (so called serious injuries) in 16.9% of cases and thus around 9 times more frequently than car occupants. Motorcyclists wearing helmets suffered head injuries in approx. 20 % of cases. The serious injuries sustained were in particular skull fractures, including base of the skull and traumatic brain injuries are rare. Severe thoracic injuries included in particular rib and shoulder/clavicle fractures, often accompanied by injuries to internal organs. In terms of spinal injuries, the most common serious injuries were fractures of the thoracic spine, followed by fractures of the lumbar spine and cervical spine. In the abdominal area there were often severe injuries in the form of fractures in the pelvic area and accompanying injuries to internal organs. Arm injuries included, besides minor injuries (grazes, bruises, etc.), most commonly fractures of the hands/fingers and forearms, followed by elbow and upper arm fractures. Leg injuries seen in particular were femoral fractures as well as injuries to the muscles and tendons around the knee, also fractures of the shin and calf bones. Around the feet there were many fractures and dislocations of the wrist and ankle joints, as well as toes. The causes of the injuries, which were recorded in detail in the study for the various regions of the body and individual injuries, were most often caused by impact with the road and collision with objects and solid vehicle structural elements of cars and trucks. Serious injuries are linked with high energy respectively high relative impact speed.

Otte, Dietmar

Thoracic Spine Extension Injuries in Occupants with Pre-Existing Conditions during Rear-End Collisions

2019-01-12224/2/2019

Certain ankylosing spondyloarthropathies such as ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH) can substantially alter clinicopathologic spine biomechanics as well as injury mechanisms in rear-end motor vehicle collisions. AS is an inflammatory disease which can lead to structural impairments of the spine secondary to flowing ossification along the spinal column, including ossification across the spinal discs, facet joints, and ligaments, and it has also been associated with diffuse osteoporosis of the spine. DISH is characterized by excess bone formation along the spinal column, encompassing the annulus and forming the thickest and strongest bridging osteophytes over adjacent vertebral bodies at the level of the disc space. In both conditions the spine is mechanically stiffened and generally more kyphotic than a healthy spine. This paper presents a series of case studies in which a front-seat occupant with ankylosing spondyloarthropathy experienced a moderate- or high-speed rear-end collision and sustained a thoracic spine fracture/dislocation, often with spinal cord injuries. Forward acceleration of the occupant by the seat back in each case resulted in straightening of the kyphotic thoracic spine and consequent extension fractures of the pathologically stiff and brittle thoracic spine. This paper illustrates the predisposition of thoracic fracture for this segment of the population with spinal pathologies such as DISH and AS in rear impacts and notes the role that seat back stiffness could play in injury mechanism for these individuals.

Davis, Mathieu, Isaacs, Jessica, Graber, Martin, Fisher, Jacob

Probability of Frontal Airbag Deployment in Bumper-Bumper and Underride Collisions

2019-01-06204/2/2019

Airbag deployment thresholds can be a useful metric of collision severity in accident reconstruction applications. The National Automotive Sampling System (NASS) has provided a publicly-available database of real-world motor vehicle collisions, including more than 10,000 event data recorder (EDR) reports retrieved from airbag control modules. These reports typically indicate the airbag deployment status and the corresponding Delta-V of each recorded event. A prior study analyzing crash data in the NASS database demonstrated the airbag deployment threshold varies between vehicle manufacturers and over time. However, the analysis was limited to Ford and GM vehicles due to insufficient data. This paper expands on the prior study of frontal airbag deployment thresholds by analyzing newer years of NASS EDR data (4,000 additional reports). We found that the Delta-V threshold for a 50% probability of deployment event is higher for Toyota than for GM and Ford vehicles. Moreover, SUVs and pickup trucks had higher deployment thresholds than sedans. An increase in Delta-V thresholds was observed for more recent vehicle model years. A higher Delta-V is required for frontal airbag deployment in underride collisions, in which a sedan contacted a vehicle with higher ground clearance (SUV, pickup truck, or van), compared to collisions with direct bumper-bumper engagement. Based on the findings, we developed a logistic regression model that predicts the probability of frontal airbag deployment with a known change in velocity (ΔV = 0 to 45 mph), vehicle manufacturer (GM, Toyota, Ford), vehicle type (sedan, SUV, pickup truck), model year (1994-2001, 2002-2016), and impact configuration (underride, bumper-bumper) with 82% accuracy. This study provides information about airbag deployment behavior beyond what is reported in owner’s manuals and National Highway Traffic Safety Administration (NHTSA) guidelines.

Lee, Felix, McCleery, Caitlin H., Ngo, Christina, Limousis-Gayda, Manon, Hashish, Rami

Lateral and Tangential Accelerations of Left Turning Vehicles from Naturalistic Observations

2019-01-04214/2/2019

Carter, Neal, Beier, Steven, Cordero, Rheana

Speeds of Child Cyclists

2019-01-04194/2/2019

Many published studies have characterized walking and running speeds of young children. However, there is a paucity of data on the cycling speeds of very young children (4 to 5 years old). The purpose of this study was to obtain an estimate of cycling speed for boys and girls both who are learning to ride bicycles (i.e., younger children who still ride with training wheels) and who have already learned to ride bicycles (i.e., slightly older children who no longer use training wheels). A sample of 32 child riders (17 boys, 15 girls; 17 four-year-olds who still ride with training wheels, 15 five-year-olds who do not) were asked to ride a short pre-defined distance at their usual speed when riding, and again at their highest speed. We found that while age and experience can differentiate riders, there were only small differences between boys’ and girls’ speeds in either age group. These descriptive results can be used in various applications from traffic engineering to accident reconstruction.

Crump, Caroline, Bui, Young

Video-Recorded “Looked-but-Failed-to-See” (LBFTS) Accidents in the Junctions of Hong Kong

2018-01-50491/18/2019

To determine causation and contributory factors of “looked-but-failed-to-see” (LBFTS) junction accidents in which the driver stated that “I did not see the pedestrian,” in-depth studies of 22 such accidents which had taken place in Hong Kong were conducted. The studied crashes were all video recorded by closed-circuit television (CCTV) cameras and/or dashboard cameras. Using the video recordings, these junction accidents were reconstructed at the scenes to determine the drivers’ views of the pedestrians and the sequence of events leading up to each accident. The results of the reconstructions and the police investigations, as well as the testimony of the drivers, were analyzed to identify causation and contributing factors of each accident. Attention error/visual search strategy (41%) and misjudgments of drivers (18%) remain the dominant cause of LBFTS crashes. However, it was found that eight crashes (36%) were attributed to the physical obstructions caused by the A-pillars of the vehicles, with the obscuration of the pedestrians being the major contributory factor. This study shows that reconstructions based on video recordings can provide detailed accounts of junction accidents to determine causations and to understand the individual characteristics of each accident. It also reveals A-pillar obscuration to be a cause of such accidents, and this provides a basis for further research on the A-pillar “blind spot.”

Cheng, Yuk Ki, Tam, Cheok Ning, Tao, Chi Hang, Tsang, Cheuk Nam

Comparative Responses of the PIPER 6YO Human Body Model and the Q6 ATD for Simulated Frontal and Lateral Impacts

SC18-22-000611/12/2018

Abstract - Adult and pediatric human body models have focused on developing accurate representation of the human body in terms of anthropometry and kinetics/kinematics in correlation with published PMHS (Post-Mortem Human Subjects) data. This study focuses on comparing the PIPER 6-year-old human body finite element (FE) model with a Q6 FE model to generate comparable metrics. The FE models were simulated in a vehicle environment by positioning them on two different child booster seats with a 3-point lap-shoulder belt for frontal and lateral impacts. The overall kinematic response (head excursion) of the PIPER human body model (HBM) mimics the behavior of the Q6 ATD. However, there is a significant difference in the NIJ values between the PIPER HBM and Q6 ATD (minimum reduction of 67% in PIPER HBM). The head-neck complex of the PIPER is seen to be more flexible (minimum reduction of 12% in neck forces and 64% in neck moments) as compared to the Q6.

Sarfare, Shreyas, Maheshwari, Jalaj, Duong, Nhat, Belwadi, Aditya

Validation of Crush Energy Calculation Methods for Use in Accident Reconstructions by Finite Element Analysis

09-06-02-000910/4/2018

The crush energy is a key parameter to determine the delta-V in accident reconstructions. Since an accurate car crush profile can be obtained from 3D scanners, this research aims at validating the methods currently used in calculating crush energy from a crush profile. For this validation, a finite element (FE) car model was analyzed using various types of impact conditions to investigate the theory of energy-based accident reconstruction. Two methods exist to calculate the crush energy: the work based on the barrier force and the work based on force calculated by the vehicle acceleration times the vehicle mass. We show that the crush energy calculated from the barrier force was substantially larger than the internal energy calculated from the FE model. Whereas the crush energy calculated from the vehicle acceleration was comparable to the internal energy of the FE model. In full frontal impact simulations, the energy of approach factor (EAF) has a linear relation with the residual crush, which had been validated in previous experimental studies. In our study using FE analysis, we found that the slope of EAF versus the residual crush was comparable with that of the dynamic crush energy versus the dynamic crush for crashes at 55 km/h. Using this slope and the residual crush from a 55 km/h impact test, the slope and the intercept of the EAF vs. residual crush can be determined using only one crash test. A database of the slopes and the intercepts was made using Japan New Car Assessment Program (JNCAP) tests. In offset impact simulations, the crush energy calculated from the crush profile agreed with the internal energy of the car FE model when at least one front rail was involved. In oblique impacts, the correction factor for crush energy is not necessary within 20 degrees of principal direction of force of the car’s longitudinal axis.

Numata, Shusuke, Mizuno, Koji, Ito, Daisuke, Okumura, Dai

A Novel Barricade Warning Light System Using Wireless Communications

2018-01-50369/12/2018

Workers in construction and transportation sectors are at increased risk for work-related injuries and fatalities by nearby traffic. Barricade-mounted warning lights meeting current specifications do not always provide consistent and adequate visual guidance to drivers and can contribute to glare and reduced safety. Through an implementation of sensors and wireless communications, a novel, intelligent set of warning lights and a tablet-based interface were developed. The lights modulate between 100% and 10% of maximum intensity rather than between 100% and off in order to improve visual guidance and adjust their overall intensity based on ambient conditions. The lights can be synchronized or operated in sequential flash patterns at any frequency between 1 and 4 Hz, and sequential patterns automatically update based on global positioning satellite (GPS) locations displayed in the control interface. A successful field demonstration of the system verified that its functions were viewed favorably by transportation safety personnel.

Rea, Mark S., Skinner, Nicholas P., Bullough, John D.

A Video-Based System for Measuring the Braking Performance of a Bicycle

2018-01-50328/27/2018

The following article describes a methodology for using a video-based system to measure the deceleration or braking performance of a bicycle after the rider applies the brakes. The bicycle’s deceleration was calculated from the equation of motion using the initial velocity and the braking distance, which is the difference between the point of brake initiation (POBI) and the bicycle’s point of rest (POR). The POBI was determined by using a GoPro camera mounted on the chain stay near the rear axle that captured a brake light wired into the rear brakes while the test cyclist rode alongside of a 100-foot surveyor tape. The POR or more specifically where the rear wheel stopped was documented next to the 100-foot surveyor tape. This methodology was evaluated under two braking conditions: rear brake only (RBO) and front and rear brake (FARB). The results demonstrated that the video-based system provided reasonably accurate measurements, on the order of 5% for assessing the braking performance of a bicycle for speeds in the range of 15 miles per hour (mph) or less. Additionally, observations regarding skid marks and rider technique during braking are also discussed.

Joganich, Timothy

The Placement of Digitized Objects in a Point Cloud as a Photogrammetric Technique

09-06-02-00078/8/2018

The frequency of video-capturing collision events from surveillance systems are increasing in reconstruction analyses. The video that has been provided to the investigator may not always include a clear perspective of the relevant area of interest. For example, surveillance video of an incident may have captured a pre- or post-incident perspective that, while failing to capture the precise moment when the pedestrian was struck by a vehicle, still contains valuable information that can be used to assist in reconstructing the incident. When surveillance video is received, a quick and efficient technique to place the subject object or objects into a three-dimensional environment with a known rate of error would add value to the investigation. In addition, once the objects have been placed into the three-dimensional environment, the investigator would then be able to observe the physical evidence and environment from any perspective, including viewing and measuring what cannot be seen in the video perspective. In this research, the proposed photogrammetric technique of visually placing objects within three-dimensional laser scans will be evaluated. This research aims to quantify the rate of error of taking measurements of these objects to known fixed reference points both in and out of view of the camera, and provide an efficient technique that can be employed by reconstructionists using only one software package. As a result of this research, the authors have developed an expedient, less time-intensive photogrammetric technique for the placement of three-dimensionally scanned objects and environments. This technique can take less than half of the time of a conventional photogrammetric solution.

Harrington, Shawn, Lebak, Gabriel

Passenger Car 25% Overlapping Collision Accident Study Base on CIDAS

2018-01-15958/7/2018

With the development of vehicle technologies, vehicle safety is much better than before, many companies put research focus on harder accident scenarios. The 25% overlapping collision is considered as one type of most dangerous collision, this paper study this type accidents base on CIDAS database. Paper showed 7 scenarios appeared frequency in China, 11, 12, 1 o’clock are main impact direction. High way and freeway are the main places, and the head, thorax and lower extremities were the main sites of injury.

Li, Xudong, Lin, Miao, Lian, Xiaowei, Cui, Fujun

Evaluation of Novel Concepts for Takeover Control using Electronically Coupled Sidesticks

F-0074-2018-12744

5/14/2018

ABSTRACT Helicopter accident investigation reports indicate that takeover control maneuvers in low level flight may lead to loss-of-control. In this paper, novel methods for control transfer are implemented to address this safety issue. Through the use of active inceptor systems, the traditional mechanical linkage between pilot and copilot inceptors can be emulated using priority functions, which act to actively decouple inceptors in one control station. Takeover control maneuvers are tested in a dual pilot helicopter simulation environment to evaluate two inceptor decoupling methods, namely a priority pushbutton (manual) and a priority force threshold (automatic). Results indicate that the takeover maneuvers were successfully performed in low level flight without over control when using both priority functions. The priority functions led to a workload reduction when compared to a benchmark configuration without inceptor decoupling. Positive ratings in usefulness and satisfaction scales indicate pilot acceptance of the priority functions tested.

Sampaio, Rodolfo, Jones, Michael, Walko, Christian

2021-12-29.TEST Theory of Collision Avoidance Capability in Automated Driving Technologies

2018-01-0044

4/3/2018

This paper proposes a theory to analyze the collision avoidance capability of automated driving technologies. The theory gives answers to a fundamental question whether automated vehicles fall into extreme conditions at all rather than another question how a vehicle reacts under extreme conditions (is it as safe as driver?). The theory clarifies the following matters: There are two types of hazards to cause collisions, cognitive hazards and behavioral hazards. Cognitive hazards are handled by controlling the upper limit speed of the automated vehicle including when stopped. There are two methods for handling behavioral hazards, preparation and response. The response known well is the coping method activated when the hazard is detected in the dynamic (operational) level. The preparation is the coping method operating at all time in the semantic (tactical) level. The collision condition in the semantic level is as follows, a collision occurs when the paths of two vehicles have a crossing point and the two vehicles drive on the crossing point at same time. The condition can be formulated as collision avoidance equation. Solving the equation means that the automated vehicle has prepared for the behavioral hazard before the hazard occurs. It is concluded that a collision avoidance capability consists of not only a response capability that supports the accuracy of collision avoidance in extreme conditions in the dynamic level but also a preparation capability that supports the accuracy to avoid reaching those extreme conditions in the semantic level. The preparation capability can be evaluated through stability analysis of the automated vehicle behavior given by the temporal backward simulation from each extreme condition. A remaining problem is how determine the upper limit of the hazards growing speed to which the automated vehicles should react.

KINDO, Toshiki, Okumura, Bunyo