Traffic Accident Reconstruction Research Articles

Rekonstrukcja miejsca zdarzenia drogowego w oparciu o dane geoprzestrzenne Geoportalu Krajowego

The purpose of the article is to analyze the potential use of free spatial data available in the National Geoportal to support traffic accident reconstruction. The research focuses on the capabilities and limitations of using LiDAR and orthophotomaps data in the context of reconstructing traffic accident scenes. A comparative methodology was employed, involving the analysis of geospatial data in relation to traditional surveying techniques, exemplified by a real traffic accident analysis using the PC-Crash soft-ware. The main findings of the research indicate high precision of orthophotos and LiDAR data in reproducing the actual topography and elements of road infrastructure. The analysis conducted on a 3D model created from LiDAR data showed that modern measurement techniques allow a more accurate reconstruction of the accident's trajectory and assessment of road visibility conditions. Integrating these data with traditional measurement methods can significantly enhance the standards of forensic experts' work, contributing to an increased accuracy in determining accident scenarios and, more broadly, to a better understanding of accident causes.

Low-cost tools for virtual reconstruction of traffic accident scenarios

Investigations into traffic accidents that lead to the determination of their causes and consequences are useful to all interested parties, both in the public and private sectors. One of the phases of investigation is the capture of data enabling the complete reconstruction of the accident scene, which is usually the point at which a conflict arises between the slow process of information gathering and the need to restore normal traffic flow. To reduce to a minimum the time the traffic is halted, this paper follows a methodology to reconstruct traffic accidents and puts forward a series of procedures and tools that are applicable to both large and small scenarios. The methodology uses low-cost UAV-SfM in combination with UAS aerial image capture systems and inexpensive GNSS equipment costing less than €900. This paper describes numerous tests and assessments that were carried out on four potential work scenarios (E−1 and E−2 urban roads with several intersections; E−3, an urban crossing with medium slopes; and E−4, a complex road section with different land morphologies), assessing the impact of using simple or double strip flights and the number of GCPs, their spacing distance and different distribution patterns. From the different configurations tested, the best results were achieved in those offset-type distributions where the GCPs were placed on both sides of the working area and at each end, with a spacing between 100 and 50 m and using double strip flights. Our conclusion is that the application of this protocol would be highly efficient and economical in the reconstruction of traffic accidents, provide simplicity in implementation, speed of capture and data processing, and provide reliable results quite economically and with a high degree of accuracy with RMSE values below 5 cm.

Force in Cable of Pretensioner Tube—A Possibility of Car Accident Reconstruction

The reconstruction of traffic accidents has grown as an interdisciplinary field, encompassing bodies of research from automotive engineering, traffic and transport engineering, biomechanics, and forensic sciences. In this work, a method is proposed by which the value of the force in the safety belt buckle can be determined provided the belt buckle is equipped with a pretensioning system with a pyrotechnic trigger in the pretensioner tube, PBP—Pyrotechnical Buckle Pretensioner, or PLP—Pyrotechnical Lap Pretensioner type. The anti-return system of the pretensioner mechanism, which prevents the passenger’s body from moving forward, contains a set of balls that block the movement of the piston in the pretensioner tube after its activation. When limiting the movement, the force the human body exerts on the safety belt webbing is transformed into the deformation of the pretensioner tube by the balls of the anti-return system. Depending on the magnitude of the force, the marks left by the balls differ. This is an alternative method for determining the force that occurs in a seatbelt and causes injury to the occupants of a vehicle. The advantage of this method is that the force in the seatbelt buckle cable can be determined relatively quickly and accurately by analyzing the deformations in the pretensioner tube, without a need for expensive laboratory equipment. The limitation of the model resides in the consideration of a static system with rigid bodies. The correlation between the normal force causing the deformation of the tube and the force in the belt buckle cable is obtained by means of a mechanical model that explains the operation of the anti-return system. By comparing the values of the normal force given by the proposed model and the elastoplastic model, a good correlation is found. Finally, a regression curve is determined to help the expert in approximating the force in the buckle cable depending on the deformation size in the pretensioner tube. The value of this force also enables biomechanical or medical specialists to correlate the degree of injury to occupants of a vehicle depending on the force in the seatbelt.

Advances in Technologies in Crime Scene Investigation.

Crime scene investigation (CSI) is the complex act of reconstructing the dynamics that led to a crime and the circumstances of its perpetration. Crystallizing the CSI is a difficult task for the forensic pathologist; however, it is often requested by the public prosecutor and many judicial cases remain unsolved precisely for this reason. Recent years have seen an improvement in the ability of 3D scanning technology to obtain dense surface scans of large-scale spaces, for surveying, engineering, archaeology, and medical purposes such as forensics. The applications of this new technology are growing every day: forensic measurement of wounds in clinical reports, for example, reconstruction of traffic accidents, bullet trajectory studies in gunshot wounds, and 3D bloodstain pattern analysis. A retrospective analysis was conducted across all crime scene investigations performed by the forensic staff of the Department of Forensic Pathology of the University of Catania from January 2019 to June 2022. Inclusion criteria were the use of a laser scanner (LS), the use of a camera, a full investigative scene, and collection of circumstantial data thanks to the help of the judicial police. Cases in which the LS was not used were excluded. Out of 200 CSIs, 5 were included in the present study. In case number 1, the use of the LS made it possible to create a complete scale plan of the crime scene in a few hours, allowing a ship to be quickly returned to the judicial police officer. In case 2 (fall from a height), the LS clarified the suicidal intent of the deceased. In case number 3 it was possible to reconstruct a crime scene after many years. In case 4, the LS provided a great contribution in making a differential diagnosis between suicide and homicide. In case 5, the LS was fundamental for the COVID team in planning the study of COVID-19 pathways and areas within a hospital with the aim of reduction of nosocomial transmission. In conclusion, the use of the LS allowed the forensic staff to crystallize the investigative scene, making it a useful tool.

Stabbed by motorcycle? Reconstruction of an unusual traffic accident

The reconstruction of traffic accidents involving powered two-wheelers (PTWs) frequently proves to be a challenging task. A case in which a fatal head-on crash of a PTW with a small truck where only minor vehicles damage was observed but resulted in isolated fatal chest trauma is discussed here. External examination of the corpse revealed two lacerations on the back, at the first glance implying sharp trauma. Based on the accident traces, the technical expert assumed an emergency break of the PTW rider resulting in a rotation of the PTW in terms of a wheelie on the front wheel. The first contact between the PTW rider and the tail end of the small truck probably occurred with the upper side of the helmet, and then, the back handle of the PTW caused the stab-like injuries followed by compression of the rider between the small truck or asphalt and the PTW. Based on the few accident traces available, neither a reconstruction of the pre-impact velocity nor a detailed reconstruction of the PTW rider kinematics was possible. However, using an interdisciplinary approach, the principal collision position as well as the injury mechanisms could be reconstructed.

Reconstruction of a real-world car-to-pedestrian collision using geomatics techniques and numerical simulations

The aim of this study is to provide an improved method for traffic accident reconstruction based on geomatics techniques and numerical simulations. A combination of various techniques was used. First, an unmanned aerial vehicle (UAV), laser scanner and structured-light scanner were used to obtain information on the accident scene, vehicle and victim. The collected traces provided detailed initial impact conditions for subsequent numerical simulations. Then, multi-body system (MBS) simulations were conducted to reconstruct the kinematics of the car-to-pedestrian collision. Finally, a finite element (FE) simulation using the THUMS model was performed to predict injuries. A real-life vehicle-pedestrian collision was used to verify the feasibility and effectiveness of this method. The reconstruction result revealed that the kinematic and injury predictions of the numerical simulations effectively conformed to the surveillance video and investigation of the actual accident. UAV photogrammetry was demonstrated to be more efficient in accident data collection than hand sketch and measurement, and 3D laser scanning enabled an easier and more accurate modeling process of vehicle. The present study shows the feasibility of this method for use in traffic accident reconstruction.

Research on the Circumstances of a Car-Cyclist Collision, Based on the Trajectory of the Cyclist's Movement after the Collision.

This article examines a simulated collision between a car and a cyclist, assessing the trajectory of the cyclist’s movement after the impact, namely the throwing distances and angles of the cyclist and bicycle. Information about the car and cyclist models used for the study is provided. Special software PC CRASH 8.1 for the analysis and reconstruction of traffic accidents was used to simulate a car–cyclist collision. Simulations of car–cyclist collisions were carried out, with different speeds for the car and the cyclist, and locations at the time of the impact. The movement of a bicycle after a crash tends to be irregular and is dependent on various parameters that are usually not possible to evaluate. Therefore, the parameters of the movement of the bicycle after the collision (the throwing angle and the distance) usually do not allow determination of the speed of the car before the accident. The movement of the cyclist after impact was more informative for determining the speed of the car before the accident. For example, when there was an angle of 30°, 60°, or 90° between the longitudinal axes of the car and the cyclist, there was a clear dependence between the speed of the car and the cyclist’s throwing distance, and usually also between the speed of the car and the cyclist’s throwing angle. Thus, in such cases, it is possible to determine approximately the initial speed of the car before the collision, based on the trajectory of the cyclist’s movement after the impact, namely his throwing distance and angle. In cases of real traffic accidents, with knowledge of the location of the car–cyclist collision and the position of the cyclist after the traffic accident, the speed of the car before the accident can be determined according to the abovementioned dependencies. Thus, the proposed methodology could be used in the reconstruction and examination of traffic accidents.

A human body model based method for injury risk prediction considering occupant stature and posture

This study developed a framework to generate injury prediction functions in order to evaluate the safety of occupants in traffic accidents, using human body model simulations to analyse the influences of crash severity, occupant stature, occupant posture, and restraint stiffness. The THUMS AM50-O Human Body Model (HBM) was used in a sled test setup. Six influencing parameters were included in injury prediction: impact velocity, occupant stature, Body Mass Index (BMI), torso angle, seating position, and seatbelt restraint force. Impact velocity was found as a significant influencing factor on skull injury, while BMI mainly affected chest injury. Sequential sampling method was used for generation of simulation matrix, and high-order interaction terms were identified. As injury prediction functions, quadratic regressions correlate better with the simulation results than other forms of regressions, the combinations of parameters in which also enhanced the robustness of injury prediction when considering uncertainty of input parameters. Using numerical models to generate injury prediction functions can better characterize occupant variations, such as sitting posture, than using traffic accident reconstruction. Such obtained functions can provide reasonable estimation on occupant injury risk based on accident information, and we also hope it may benefit vehicle safety improvement and triage protocol in medical treatments of traffic accident victims.

Falling Direction of Motorcycle and Its Application in Traffic Accident Reconstruction

Falling Direction of Motorcycle and Its Application in Traffic Accident Reconstruction

Uncertain inverse traffic accident reconstruction by combining the modified arbitrary orthogonal polynomial expansion and novel optimization technique

Traffic accident reconstruction accomplished by traditional deterministic inverse method is highly user-interactive and time-consuming and its solution is hard to convince in court due to various uncertainty in measurements, calculation and modeling. To rapidly identify the unknown impact parameters and simultaneously quantify their uncertainty, an uncertain inverse traffic accident reconstruction is accomplished by combining the modified arbitrary orthogonal polynomial expansion (AOPE) which can accurately and effectively construct surrogate models and novel optimization technique which solves the uncertain inverse problem by deterministic method. First, a dynamic model is built to simulate a traffic accident. Then, using the optimal Latin hypercube design, the impact responses fluctuating greatly with the change of unknown impact parameters are selected as the evaluation index of reconstruction quality. Using the random forest algorithm, the impact parameter importance is evaluated according to the SHAP values. Subsequently, a modified AOPE is presented based on the impact parameter importance measures. The mappings for an actual traffic accident are approximated using the modified AOPE to reduce the computational burden and guarantee the fitting precision. Finally, based on the novel optimization technique, the uncertain inverse traffic accident reconstruction is defined to search the optimal distributions of unknown impact parameters which make the distributions of simulation results of impact responses match these of accident investigation. The uncertainty is propagated by the Monte Carlo simulation in the optimization process. An actual vehicle-to-two-wheeler accident is applied to explain this uncertain inverse traffic accident reconstruction, and the mean values of unknown impact parameters are assigned into the established simulation model to check the effectiveness of results. By matching the simulated and actual impact responses, it shows that the proposed approach is efficient and reliable for traffic accident reconstruction under uncertainty. This approach can help the accident investigators and judges reasonably evaluate the behavior of accident participants and complete the accident responsibility confirmation.

Metodika získavania vonkajšej geometrie segmentov novej generácie skúšobnej figuríny

The article presents the fulfilment of a partial goal of the research project focused on developing and constructing a biofidelic surrogate of the human body to improve the forensic reconstruction of road traffic accidents. It aims to describe the methods and results of acquiring external geometry of segments of crash test dummy Hybrid III. To create a precise spatial representation of dummy segments, we applied 3D laser scanning using the handheld 3D scanner VIUscan Handyscan 3D. The workflow, used material and application of software support are closely described in the methodical part of the article. The results present 3D models of significant material for the continuous fulfilment of project goals. In the follow-up activities, we will use dummy external geometry data, particularly to develop molds for casting segments of new-generation synthetic human body surrogates.

PERSONALIZED CUSTOMIZATION METHOD OF HYBRID HUMAN MODEL FOR PEDESTRIAN-VEHICLE ACCIDENT RECONSTRUCTION

Traffic accident reconstruction is a reverse dynamic problem, which requires hundreds of iterations to reconstruct the whole process of accident. However, in current pedestrian-vehicle accident reconstructions, it is difficult to quickly establish a pedestrian model based on specific cases, and it is hard to solve the contradiction between calculation accuracy and calculation time. In this paper, a personalized pedestrian customization method is proposed. First, the pedestrian structure is divided into independent modules according to obvious bony markers. For each independent module, multi-body (MB) model and finite element (FE) model are established, respectively. Then the appropriate modules are selected to form the whole hybrid pedestrian model. This method can customize the structure of pedestrian model according to the injury characteristics of pedestrians in specific accidents, and customize the parameters of pedestrian model according to the height and weight of pedestrians. The impact simulation tests are carried out on hybrid pedestrian models to verify the reliability of the models. The proposed method can effectively improve the modeling efficiency of pedestrian models and the reconstruction quality of pedestrian traffic accidents.

Mogućnost rekonstrukcije saobraćajnih nesreća pomoću uređaja za beleženje podataka - pregledni rad

Event Data Recorders (EDRs) have been used for the purpose of investigating traffic accidents for more than 20 years. Some countries have regulated their application by law, and they are a valid evidence during investigations and reconstructions. However, recording devices are used as a source of information, not as a database from which it is possible to reconstruct the event. Investigations using only recording devices are still not possible due to the some phenomena that exist, and due to the constructional features of the devices. Scientists from Japan and Poland tested the accuracy of the data from the devices and performed reconstructions of accidents. Both teams have established that it is possible to perform reconstruction only in simple situations, such as a straight-line crash of one vehicle into another. When there are several participants in a crash, or a crash was preceded by a maneuver, it is not possible to determine what really happened. Further development of data recording devices is necessary, in order to increase their efficiency during the reconstruction of traffic accidents.

Experimental study of the factors affecting the parameters of emergency braking process for vehicles of category M1

The paper presents the results of an experimental study of the parameters of emergency braking process for vehicles of category M1, wherein disclosed is the influence of a combination of factors such as: actual loading of a vehicle, the presence of ABS, EBD, BAS systems, a trailer of up to 750 kg, condition of the road surface, and seasonality types of tires. As a result of the study, the actual values of the steady-state deceleration jyз and its rise time tвp, were obtained, and their comparative analysis with the recommended standard values was carried out. The paper also presents reliable mathematical models in terms of their practical application during the reconstruction of road traffic accidents.

Reverse reconstruction of two-wheeled vehicle accident based on Facet vehicle model and hybrid human model

To obtain a rider-vehicle-road coupling system that takes both efficiency and accuracy into account, so that the simulation model of two-wheeled vehicle traffic accident can reduce the calculation time as much as possible on the premise that it can simulate human biomechanical injury and vehicle deformation, this paper proposes a new two-wheeled vehicle accident simulation model. In this method, the vehicle uses the Facet model, and the cyclist uses the hybrid human model. The coupling system of rider-vehicle-road is established and the effectiveness of the system is verified. For the collision accident between the car and two-wheeled vehicle, the simulation model is used to reconstruct in MADYMO. The results show that the motion posture of cyclists and vehicles after the collision is consistent with the accident situation, and the human injury data is consistent with the medicolegal expertise, which verifies the feasibility and effectiveness of this simulation model. This modelling method provides a new idea for the reconstruction of two-wheeled traffic accidents and the general dynamic simulation.

Topography, the primary basis of the reconstruction of a traffic accident

The following document applied to the investigation and reconstruction of traffic accidents, seeks to conceptualize the serious errors that exist in many public and private institutions when considering that the reconstruction of a traffic accident is to determine the vehicle speed, with one or more physical equations or in the worst case, a 2D or 3D animation of an alleged traffic accident dynamics, as well as explain confused concepts and procedures in the field of criminal investigation, specifically in the reconstruction of traffic accidents. Starting from the premise that the reconstruction of a violent in traffic death essentially seeks the identification and clearancing of variables in the investigation, also exposing not very clear concepts regarding the topic of interest; from the above, important errors are determined in the concepts that we have of what is a forensic reconstruction, the hypotheses that are used in the sketch of traffic accidents in Colombia and the great errors that exist in the matter of fixing physical evidence (EF).

A damage model for the simulation of crack initiation and propagation in automotive windshield laminated glass structures

Accident reconstructions and numerical simulations are used to evaluate and improve protective systems. Virtual testing and numerical methods can assist in the improvement safety of vulnerable road users. This work presents the tremendous potential of using computer-aided engineering by describing the development of a windshield numerical model and its damage and fracture validation. The motivation behind this study is the possibility of using such a model in the reconstruction of road accidents involving vulnerable road users. The main goal is the development and validation of a finite element model of an automobile windshield in order to use it in further studies regarding the reconstruction of road traffic accidents. In order to validate it according to experimental studies available in the literature, the 4.8 kg standard adult headform from the European Enhanced Vehicle Safety Committee is also developed and validated. A total of eight impacts at six different locations and carried at two different impact velocities (6 m/s and 11.1 m/s) were simulated. The validation of the windshield model, and consequently the damage model employed to simulate glass cracking initiation and propagation, were accomplished by comparing the acceleration at the headform’s centre of gravity and the windshield’s fracture pattern against experimental data.

АУДИТ БЕЗОПАСНОСТИ ДОРОЖНОГО ДВИЖЕНИЯ НА ФЕДЕРАЛЬНЫХ ТРАССАХ КРАСНОЯРСКОГО КРАЯ

The paper considers an assignment and an essence of audit of road traffic safety. As an example, the authors have determined a priority section on federal roads of Krasnoyarsk Territory for conducting the audit. On the basis of detailed analysis of road conditions that affect the risk of accidents appearance and research of road traffic accidents mechanism on that section the authors have developed measures on decreasing accident rate. Efficiency of the proposed measures are verified with the use of PC–Crash program for modeling and reconstruction of road traffic accidents.

Reconstruction of Vehicle-pedestrian Collision Road Traffic Accidents Based on PC-Crash Software.

Objective To discuss the application value of vehicle-pedestrian collision road traffic accidents reconstruction based on PC-Crash software in forensic identification. Methods A case of vehicle-pedestrian collision was chosen based on a tachograph, then PC-Crash software was applied to construct a vehicle-pedestrian collision model, and reconstruct the vehicle-pedestrian collision road traffic accident. Finally, the process of vehicle-pedestrian collision was reproduced. Results In accident reconstruction, when the car speed was lower than 50km/h, the landing point of the pedestrian after collision was in the front of the car. When the car speed was higher than 50 km/h, after collision, the pedestrian flipped towards the car roof and landed behind the car. With the increase of vehicle speed, throwing distance of the pedestrian increased continuously. When the vehicle collision speed reached 60 km/h, the experimental results in this case were basically consistent with the actual situation of the case. Head acceleration of the pedestrian was at the maximum （1 655.70 m/s2） at 0.080 s. Chest acceleration of the pedestrian increased from 597.63 m/s2 to the peak 675.52 m/s2 at 0.055-0.060 s. Tibia acceleration of the pedestrian increased from 759.26 m/s2 to the first peak 1 367.06 m/s2, then reached the maximum speed （1 718.19 m/s2） at 1.225 s. Conclusion The process of vehicle-pedestrian collision road traffic accidents can be reconstructed based on PC-Crash software under a situation of limited conditions, and can further clarify the speed of the vehicle, the location and degree of human body injury as well as the mechanism of damage of the pedestrian in the accident. Therefore, PC-Crash software has a certain practical value in forensic identification of road traffic accidents.

Reconstruction of traffic situations from digital video-recording using method of volumetric kinetic mapping

In the past the traffic accident reconstruction was based in principle only on indirect methods that use accident marks and witness reports. These data were then used within backward reconstruction of event for determination of motion status of accident participants and expression of desirable quantities as are initial velocities, impact velocities, distances travelled or temporal conditions. These methods and their accuracy are dependent on the width of intervals of input quantities or on limited possibilities for motion synchronization between numerable participants of road traffic accidents. Existence of footage from CCTV cameras that captures traffic situations presents very valuable source of information about these accidents. The goal of the article is proposal of a volumetric kinetic mapping (VKM) method of accident reconstruction from CCTV footage. The method is based on synthesis of videoediting, videoanalysis and kinetic simulation using dedicated software for accident reconstruction. The method was furthermore validated for speed-time and distance-time variables by means of experimental test runs and by subsequent application of the method in the reconstruction of these tests using PC-Crash simulation software and two videoediting software packages. Results of the reconstructions of validation runs using VKM method were then verified by comparing them to the measured data from Corrsys Datron Microstar measuring system.