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Journal Article

A Bayesian Approach to Cross-Validation in Pedestrian Accident Reconstruction

2011-04-12
2011-01-0290
In statistical modeling, cross-validation refers to the practice of fitting a model with part of the available data, and then using predictions of the unused data to test and improve the fitted model. In accident reconstruction, cross-validation is possible when two different measurements can be used to estimate the same accident feature, such as when measured skidmark length and pedestrian throw distance each provide an estimate of impact speed. ...In accident reconstruction, cross-validation is possible when two different measurements can be used to estimate the same accident feature, such as when measured skidmark length and pedestrian throw distance each provide an estimate of impact speed. ...An actual measurement falling in an extreme tail of the predictive distribution suggests a weakness in the assumptions governing the reconstruction. This paper describes an implementation of these ideas using the Bayesian freeware WinBUGS.
Technical Paper

Predicting Weight Distribution from Occupant Load Using a Monte Carlo Method

2012-09-24
2012-01-1925
Actual occupant weight distributions versus certified weight per occupant seat causes a potential conflict between a vehicle's in-use weight versus its certified GVWR. A Monte Carlo method using a midsized bus example was conducted to determine the statistical probability that adult passengers and rated cargo would result in weight distributions that exceeded tire load capability, Gross Axle Weight Rating (GAWR), or GVWR.
Technical Paper

Stereoscopic Animation for Accident Reconstruction

1993-03-01
930905
Stereoscopic animation is presented. The fundamentals behind the technology are shown to be rooted in common video hardware and software. The elements of programming for separating an animation into its components and creating three-dimensional frames are described in principle. The use of the technologyin sightlinequestions, distanceperception, occupant dynamics problems, and machine motion is discussed.
Technical Paper

LIMITATIONS OF ATB/CVS AS AN ACCIDENT RECONSTRUCTION TOOL

1997-02-24
971045
This paper explores the usage of the Articulated Total Body Program (ATB) as an accident reconstruction tool. The importance of model validation is discussed. Specific areas of concern such as the contact model, force-deflection data, occupant parameters, restraint system models, head/neck loadings, padding, and intrusion are discussed in the context of accident reconstruction. ...Specific areas of concern such as the contact model, force-deflection data, occupant parameters, restraint system models, head/neck loadings, padding, and intrusion are discussed in the context of accident reconstruction....Occupant simulation models have been used to study trends or specific design changes in “typical” accident modes such as frontal, side, rear, and rollover. This paper explores the usage of the Articulated Total Body Program (ATB) as an accident reconstruction tool.
Technical Paper

Velocity Histories as an Accident Reconstruction Tool

1985-02-25
850249
The objective of this paper is to illustrate how the use of velocity diagrams of both vehicle and occupant motion can be of great assistance to the accident reconstructionist. The technique, best applied in the early stages of the reconstruction process, is recommended to (1) reduce the likelihood of arithmetic or equation misapplication errors, (2) permit estimates for such accident parameters as mutual crush and impact duration, and (3) provide insights into the critical issues of the reconstruction. ...The technique, best applied in the early stages of the reconstruction process, is recommended to (1) reduce the likelihood of arithmetic or equation misapplication errors, (2) permit estimates for such accident parameters as mutual crush and impact duration, and (3) provide insights into the critical issues of the reconstruction. ...The technique, best applied in the early stages of the reconstruction process, is recommended to (1) reduce the likelihood of arithmetic or equation misapplication errors, (2) permit estimates for such accident parameters as mutual crush and impact duration, and (3) provide insights into the critical issues of the reconstruction. For analyzing occupant motion, reasonably realistic models of compartment response are proposed based on either a cosine model or a model derived from the CRASH computer programs.
Technical Paper

Forensic Laboratory Support to Accident Reconstruction

1987-02-01
870427
Proper reconstruction of an accident requires input from witnesses and experts representing different disciplines. ...It is especially important to be cognizant of these areas inasmuch as the accident scene is a transient phenomenon, subject to alteration and even destruction.
Technical Paper

Vision and Visibility in Vehicular Accident Reconstruction

1990-02-01
900369
This determination must be made with proper consideration of both inter- and intra-person variability The goal of accident reconstruction is to determine what happened in an accident, and why it happened. This process involves a thorough examination of the available evidence. ...Furthermore, the question of why the accident happened may not be addressed at all by analysis of the physical evidence alone, as almost all accidents are influenced by the performance of the people involved in the accident. Human performance issues such as vision, attention, and distraction, often play a large role in why an accident happens. ...The purpose of this paper is to illustrate the value of considering issues of vision and visibility when reconstructing an accident. Illustrative examples from actual accidents will be used throughout.
Journal Article

GPS Device Comparison for Accident Reconstruction

2012-04-16
2012-01-0997
The GPS (Global Positioning System) is a navigational tool available to the public, comprising in part a network of satellites in orbit broadcasting signals to GPS receivers on earth. Due in large part to the very accurate clocks in the system, a GPS receiver that receives a number of these signals simultaneously can then establish its location on earth. Some GPS receiver models have the capability to record a history of the latitude and longitude co-ordinates at known times, and these may later be downloaded and viewed on a computer using applicable software. Effectively, this provides the equivalent of a bread crumb trail of the path taken by the receiver, although the frequency of the data points can vary substantially from one model to another, and it may not be adjustable by the user. By plotting the information on a map, the trail can be viewed and the position-time history of the vehicle may become evident.
Technical Paper

Perception/Reaction Time Values for Accident Reconstruction

1989-02-01
890732
Field literature in testing and experimentation on general human perception and reaction times, was reviewed to better address questions on the parameters of driving performance. Brake reaction time studies and driver visual search studies were reviewed with attendant material on the effects of aging, intoxication and fatigue. A short examination is made on the degree of increase in “surprise intrusion” event upper values from simple human basic reaction time testing to a real-time pedestrian crossing event in real-world urban driving. These upper range values began at 0.78 second in the laboratory environment and became 2.50 seconds on an urban street in real-time.
Technical Paper

Microcomputer Programs Useful for Aspects of Accident Reconstruction

1980-02-01
800174
The listings of two programs written in the BASIC language for use on microcomputers are presented. The first, APPLETRAJ, is oriented toward discovery of the initial conditions required of a skidding vehicle to match trajectory evidence. The second, APPLECRASH, uses sets of geometric, inertial and energy absorbing vehicle parameters to interpret the crush shapes of a pair of crashed vehicles into a value for the system linear impulse. From the impulse the Delta-Velocity and the Delta-Omega of each vehicle are found. In addition, the peak forces that the model uses are presented. Both programs feature graphics screen prompting of input and feedback of geometries, kinematic information and final reporting.
Technical Paper

An Inexpensive, All Solid-state Video and Data Recorder for Accident Reconstruction

1999-03-01
1999-01-1299
A video and data recording is very helpful for accurate accident reconstruction. We have made a prototype of a “personal eye witness”: a small video camera with solid state memory and a short recording time. ...The camera records continuously until it senses an accident, then it saves a video record of the events surrounding the accident in time. Since video is available from both before and after the collision, accident reconstruction becomes easier. ...Since video is available from both before and after the collision, accident reconstruction becomes easier. The camera uses only solid state memory with no moving parts, can be manufactured inexpensively, and can be packaged in a crash-resistant and tamper-resistant module.
Technical Paper

Introduction to Traffic Signal Data Loggers and their Application to Accident Reconstruction

2018-04-03
2018-01-0527
Until relatively recently, investigators were limited by the absence of any recording devices within the systems used for traffic signal phasing and timing. Accident reconstruction methods have long relied on the generalized signal phasing and timings programmed for that intersection by the responsible jurisdiction, combined with the vehicle dynamics calculated for the collision sequence in conjunction with witness testimony regarding signal indications and phase changes. ...This paper also presents how to obtain, analyze, and interpret the data logger data and possible applications of such data to accident reconstruction.
Technical Paper

Lane Change Maneuver Modeling for Accident Reconstruction Applications

2002-03-04
2002-01-0817
Lane change maneuvers are often implemented in typical driving applications and more severe swerving maneuvers are occasionally performed in order to avoid motor vehicle collisions. For accident reconstruction purposes, it is necessary to accurately model the vehicle motion and driver response during a lane change maneuver.
Technical Paper

Data Retrieval by Accident Reconstruction for Safer Vehicle Design

1972-02-01
720284
The effectiveness of safety design must be justified in terms of real automobile accidents with human occupants. Since it is far too dangerous to use human subjects in full-scale collision experiments, substitutes are usually studied, that is, experiments performed with dummies and mathematical models. ...Full-scale collision experiments with human occupants could be performed by reconstructing real automobile accidents accurately. To retrieve the most needed data for further improvements in safety design and to translate actual accidents as controlled experiments, an engineered method was developed to reconstruct accidents. ...To retrieve the most needed data for further improvements in safety design and to translate actual accidents as controlled experiments, an engineered method was developed to reconstruct accidents.
Technical Paper

Large and Small Car Accident Performance: A Large Scale Accident Data Base Analysis

1975-02-01
750113
New York State's development of a system for examining the relationship between vehicle design and traffic crash incidence and injury severity made possible a study of the relationship between small car and large car accident performance. Accident involved vehicles were studied using such variables as make, model year, shipping weight, horsepower, and accident data such as impact area, road conditions, and seat belt use. ...Accident involved vehicles were studied using such variables as make, model year, shipping weight, horsepower, and accident data such as impact area, road conditions, and seat belt use. Considering these and other variables, occupants of the smaller cars experienced higher rates of injury severity in crashes than occupants of larger cars.
Technical Paper

Protocol for the Examination of School Bus Vehicles to Support Accident Investigation and Reconstruction

1998-02-23
980374
This paper provides a protocol for the examination of school bus vehicles to support accident investigation and reconstruction. The topics covered are generally beyond what is normally conducted during a routine commercial motor coach accident investigation. ...The topics covered are generally beyond what is normally conducted during a routine commercial motor coach accident investigation. Included are suggested points on administrative preparation, information research, logistics, examination equipment preparation, photography, and safety precautions.
Technical Paper

Accident Reconstruction with Data Recorded by Electronic Control Units in Vehicles with a Pre-crash Safety System

2018-04-03
2018-01-1440
Data recorded by vehicle-mounted electronic control units (ECUs) are highly useful in traffic accident reconstruction. In this context, event data recorders (EDRs) are airbag ECU components used to log information from crash events, typically providing data on speed, accelerator operation, RPMs and brake lamp activation for a period of around 5 s before a collision. ...Thus, it is important to check the accuracy of EDR speed data in accident reconstruction. Meanwhile, pre-crash safety systems (PCSs) are also becoming more widespread in automobile usage today. ...Such systems automatically apply braking in hazardous situations, and the relevant data recorded in the ECU are promising in the field of accident reconstruction. This study involved physical tests in the form of simulated rear-end collisions and the collection of recorded PCS data at the post-test stage.
Journal Article

Validation of an FE Lower Limb Model for a Child Pedestrian by Means of Accident Reconstruction

2008-04-14
2008-01-1240
The results of the FE accident reconstruction showed that the observed lower limb fracture patterns were reproduced within the estimated individual variation of material property. ...In their previous study, the authors have developed a methodology for validating a child FE model by reconstructing pedestrian accidents and comparing predicted and observed injuries. However, the study reconstructed only one accident case and more validation cases were needed for enhanced confidence of the estimated material property. ...However, the study reconstructed only one accident case and more validation cases were needed for enhanced confidence of the estimated material property.
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