Display:

Results

Viewing 121 to 150 of 16153
2015-04-14
Technical Paper
2015-01-1413
Louis Tijerina, Michael Blommer, Reates Curry, Radhakrishnan Swaminathan, Dev Kochhar, Walter Talamonti
Abstract This paper investigates the effects on response time of a forward collision event in a repeated-measures design. Repeated-measures designs are often used in forward collision warning (FCW) testing despite concerns that the first exposure creates expectancy effects that may dilute or bias future outcomes. For this evaluation, 32 participants were divided into groups of 8 for an AA, BB, AB, BA design (A= No Warning; B=FCW alert). They drove in a high-fidelity simulator with a visual distraction task. After driving 15 min in a nighttime rural highway environment, a forward collision threat arose during the distraction task (Period 1). A second drive was then run and the forward collision threat was repeated again after ∼10 min (Period 2). The response times from these consecutive events were analyzed.
2015-04-14
Technical Paper
2015-01-1414
Jitendra Shah, Mohamed Benmimoun
Abstract The focus of this paper is the threat assessment of perceived threat by drivers in collision avoidance situations. The understanding of the decision making process with regards to the initiation of a driver intervention is a crucial step to gain insight into driver's steering and braking behavior in case of an imminent threat (rear-end collision). Hence a study with various test subjects and a test vehicle has been conducted. The study has helped to understand how drivers behave in potential rear-end collision situations arising from the traffic situation (e.g. start of a traffic jam). This information is of major importance for designing autonomous collision avoidance systems and an important step towards autonomous driving. Autonomous driving in vehicles require system interventions to be initiated as early and safely as possible in order to avoid the collision and to avoid unstable vehicle dynamics situations.
2015-04-14
Technical Paper
2015-01-1415
Yasuhiro Matsui, Shoko Oikawa
Abstract Fatal injuries suffered by cyclists in vehicle-versus-cyclist accidents are investigated to provide information for the introduction of safety countermeasures. We analyzed characteristics of cyclist injuries in real fatal accidents and compared them with severity levels of head injury in impact tests against a road surface. In the accident analyses, we investigated the main body regions whose injuries led to fatalities using a macro vehicle-cyclist accident database of the Institute for Traffic Accident Research and Data Analysis of Japan. Using data from 2009 to 2013, we investigated the frequency of cyclist fatalities by gender, age group, vehicle speed, and the source of fatal head injury (impact with the vehicle or road surface). Results indicated that head injuries are the most common cause of cyclist fatalities in car-cyclist accidents.
2015-04-14
Technical Paper
2015-01-1416
Clay Coleman, Donald Tandy, Jason Colborn, Nicholas Ault
Abstract In the field of accident reconstruction, a reconstructionist will often inspect a crash scene months or years after a crash has occurred. With this passage of time important evidence is sometimes no longer present at the scene (i.e. the vehicles involved in the crash, debris on the roadway, tire marks, gouges, paint marks, etc.). When a scene has not been totally documented with a survey by MAIT or the investigating officers, the reconstructionist may need to rely on police, fire department, security camera, or witness photographs. These photos can be used to locate missing evidence by employing traditional photogrammetric techniques. However, traditional techniques require planar surfaces, matched discrete points, or camera matching at the scene.
2015-04-14
Technical Paper
2015-01-1418
Shane Richardson, Nikola Josevski, Andreas Sandvik, Tandy Pok, Tia Lange Orton, Blake Winter, Xu Wang
Abstract Pedestrian throw distance can be used to evaluate vehicle impact speed for wrap or forward projection type pedestrian collisions. There have been multiple papers demonstrating relationships between the impact speed of a vehicle and the subsequent pedestrian throw distance. In the majority of instances, the scenarios evaluated focused on the central width of the vehicle impacting the pedestrian. However, based on investigated pedestrian collisions, the location where the pedestrian has engaged with the vehicle can and does significantly influence the throw distance (and projection) and subsequent impact speed analysis. PC-Crash was used to simulate multiple pedestrian impacts at varying speeds and vehicle impact locations, creating pedestrian throw distance impact speed contour plots. This paper presents the pedestrian throw distance impact speed contour plots for a range of nine vehicle types.
2015-04-14
Technical Paper
2015-01-1417
Jeffrey Muttart
Abstract Controlled studies identified several factors that influence drivers' swerving when responding to in an emergency situation. Specifically, driver age, time-to-contact, amplitude of the steering action (steer within lane or swerving into the next lane), distraction, fatigue, natural lighting and available buffer space were identified as factors that influence steering behaviors. The goal of the current research was to identify the extent to which each factor changed swerving performances of drivers who were faced with a crash or near crash. Results from crashes and near crashes were obtained from the InSight (SHRP-2) naturalistic driving study. The results from the controlled studies and the results from the naturalistic driving research were consistent in many ways. Drivers engaged in a visual-manual secondary task were much younger than were the drivers who had no distracting secondary task.
2015-04-14
Technical Paper
2015-01-1419
Raymond M. Brach
Abstract Numerous algebraic formulas and mathematical models exist for the reconstruction of vehicle speed of a vehicle-pedestrian collision using pedestrian throw distance. Unfortunately a common occurrence is that the throw distance is not known because no evidence exists to locate the point of impact. When this is the case almost all formulas and models lose their utility. The model developed by Han and Brach published by SAE in 2001 is an exception because it can reconstruct vehicle speed based on the distance between the rest positions of the vehicle and pedestrian. The Han-Brach model is comprehensive and contains crash parameters such as pedestrian launch angle, height of the center of gravity of the pedestrian at launch, pedestrian-road surface friction, vehicle-road surface friction, road grade angle, etc. Such an approach provides versatility and allows variations of these variables to be taken into account for investigation of uncertainty.
2015-04-14
Technical Paper
2015-01-1420
John C. Steiner, John Olsen, Tom Walli, Tyler Kress, Christopher Armstrong, Ralph Gallagher, Stein Husher, John Kyes
Abstract Traditional accident reconstruction analysis methodologies include the study of the crush-energy relationship of vehicles. By analyzing the measured crush from a vehicle involved in a real world accident and comparing it to a test vehicle with a known energy, from a crash test, the real world vehicle's damage energy can be evaluated. In addition, the change-in-velocity (Delta-V) can be calculated. The largest source of publicly available crash tests is from the National Highway Traffic Safety Administration (NHTSA). NHTSA conducts numerous Federal Motor Vehicle Safety Standard (FMVSS) compliance and New Car Assessment Program (NCAP) testing for many passenger vehicles for sale in the United States.
2015-04-14
Technical Paper
2015-01-1427
Jay Przybyla, Jason Jupe, Thomas Rush, Rachel Keller
Abstract Vehicles involved in rollover crashes can leave debris trails which can include glass from broken windows. The glass patterns can be useful to identify the vehicles path during the rollover and the location and orientation of the vehicle at various vehicle-to-ground impacts. The location of glass, which is often window specific, can be used to identify where the window fractured during the rollover sequence. The longevity of the glass debris fields, subject to various real-world conditions and disturbances (i.e. slope, weather, mowing, soil type, etc.), was tested over a period of two years. The glass debris fields were placed and mapped in multiple locations across the United States. Periodically during each year, the glass debris fields were examined and the new field extents were mapped. The comparison between the original debris field and the subsequent debris fields are presented.
2015-04-14
Technical Paper
2015-01-1421
Dennis Turriff, David J. King, James Bertoch
Abstract Vehicle rollovers generate complicated damage patterns as a result of multiple vehicle-to-ground contacts. The goal of this work was to isolate and characterize specific directional features in coarse- and fine-scale scratch damage generated during a rollover crash. Four rollover tests were completed using stock 2001 Chevrolet Trackers. Vehicles were decelerated and launched from a rollover test device to initiate driver's side leading rolls onto concrete and dirt surfaces. Gross vehicle damage and both macroscopic and microscopic features of the scratch damage were documented using standard and macro lenses, a stereomicroscope, and a scanning electron microscope (SEM). The most evident indicators of scratch direction, and thus roll direction, were accumulations of abraded material found at the termination points of scratch-damaged areas.
2015-04-14
Journal Article
2015-01-1426
Drew A. Jurkofsky
Abstract Photogrammetry from images captured by terrestrial cameras and manned aircraft has been used for many years to model objects, create scale diagrams and measure distances for use in traffic accident investigation and reconstruction. Due to increasing capability and availability, Unmanned Aircraft Systems (UAS), including small UAS (SUAS), are becoming a valuable, cost effective tool for collecting aerial images for photogrammetric analysis. The metric accuracy of scale accident scene diagrams created from SUAS imagery has yet to be compared to conventional measurement methods, such as total station and laser measurement systems, which are widely used by public safety officials and private consultants. For this study, two different SUAS were used to collect aerial imagery for photogrammetric processing using PhotoModeler software.
2015-04-14
Technical Paper
2015-01-1424
Jeffrey Croteau, Charles L. Crosby, Micky Marine, Andrew Kwasniak
Abstract Bollard systems are often used to separate errant vehicular travel from pedestrian and bicycle traffic. Various bollard systems are available for this function, including different installations, functional design, and protection levels. The security-type bollards are used primarily at high-security locations (e.g., military bases and other government installations) around the world. While a protocol exists for testing and rating security bollards, no such protocol or recommended practice or standard currently exists for non-security-type bollards. Non-security, concrete-filled bollards are commonly used by cities/states, local government organizations, and the private sector as “perceived impediments to access” to protect against slow-moving vehicles. There is a general lack of publically available test data to evaluate these non-security bollards and conventional installation procedures.
2015-04-14
Journal Article
2015-01-1422
Neal Carter, Nathan A. Rose, David Pentecost
Abstract Several sources report simple equations for calculating the lean angle required for a motorcycle and rider to traverse a curved path at a particular speed. These equations utilize several assumptions that reconstructionists using them should consider. First, they assume that the motorcycle is traveling a steady speed. Second, they assume that the motorcycle and its rider lean to the same lean angle. Finally, they assume that the motorcycle tires have no width, such that the portion of the tires contacting the roadway does not change or move as the motorcycle and rider lean. This study reports physical testing that the authors conducted with motorcycles traversing curved paths to examine the net effect of these assumptions on the accuracy of the basic formulas for motorcycle lean angle. We concluded that the basic lean angle formulas consistently underestimate the lean angle of the motorcycle as it traverses a particular curved path.
2015-04-14
Technical Paper
2015-01-1430
Brian Gilbert, Joseph McCarthy, Ron Jadischke
Abstract The analysis and modeling of vehicle crush in accident reconstruction has traditionally been based upon the use of linear, crush-based, stiffness coefficients. Recent advances have allowed for the calculation and implementation of non-linear crush coefficients in the accident reconstruction software Human-Vehicle-Environment (HVE) by Engineering Dynamics Corporation (EDC). HVE contains the collision algorithm called DyMESH (DYnamic MEchanical SHell), which is capable of using the non-linear coefficients. These non-linear coefficients have shown to increase the accuracy of a predicted crash pulse. Published research on non-linear crush coefficients for the use in HVE has been limited to frontal impacts. Calculating side stiffness coefficients is more complex since most side impact crash tests involve two vehicles that can crush and absorb impact energy.
2015-04-14
Technical Paper
2015-01-1429
Jeffrey Aaron Suway, Judson Welcher
Abstract Federal Motor Vehicle Safety Standard (FMVSS) No. 108 has minimum performance requirements for retroreflective tape at different entrance and observation angles. In the author's preliminary research, all DOT-C2 retroreflective tape on the market is advertised as meeting and exceeding FMVSS No. 108 requirements. The authors' literature review revealed that there have been no publications quantifying the performance of commercially available DOT-C2 retroreflective tape across a wide range of entrance and observation angles. Therefore, without additional study, an accident reconstruction expert cannot know exactly how a specific type of compliant tape may perform, beyond the minimum federal requirements. In an attempt to solve this issue, the authors have quantified the performance of different types of retroreflective tape with a retroreflectometer.
2015-04-14
Technical Paper
2015-01-1428
Shane Richardson, Andreas Moser, Tia Lange Orton, Roger Zou
Abstract Current techniques that can be used to evaluate and analyse lateral impact speeds of vehicle crashes with poles/trees are based on measuring the deformation crush and using lateral crash stiffness data to estimate the impact speed. However, in some cases the stiffness data is based on broad object side impacts rather than pole impacts. Some have argued that broad object side impact tests can be used for analysing narrow object impacts; however previous authors have identified the fallacy of this premise. Publicly available side pole crash test data is evaluated in terms of crush depth impact speed and impact energy for six general vehicle types. A range of simulated pole impact tests at various speeds and impact angles were conducted using LS-Dyna and PC-Crash. Publicly available Finite Element Vehicle models of a 1996 Ford Taurus, a 1994 Chevrolet C2500 and a 1997 Geo Metro (Suzuki Swift) were used, providing relationships among impact speeds, crush depths and impact angles.
2015-04-14
Technical Paper
2015-01-1435
Jeffrey Wirth, Enrique Bonugli, Mark Freund
Abstract Google Earth is a map and geographical information application created and maintained by Google Corporation. The program displays maps of the Earth using images obtained from available satellite imagery, aerial photography and geographic information systems (GIS) 3D globe. Google Earth has become a tool often used by accident reconstructionists to create site drawings and obtain dimensional information. In some cases, a reconstructionist will not be able to inspect the site of the crash due to various circumstances. For example, a reconstruction may commence after the roadway on which the accident occurred has been modified. In other cases, the time and expense required to physically inspect the incident site is not justifiable. In these instances, a reconstructionist may have to rely on Google Earth imagery for dimensional information about the site. The accuracy of Google Earth is not officially documented.
2015-04-14
Technical Paper
2015-01-1434
Gary A. Davis
Abstract Martinez and Schlueter [6] described a three-phase model for reconstructing tripped rollover crashes, where the vehicle's path is divided into pre-trip, trip, and post-trip phases. Brach and Brach [9] also described this model and noted that the trajectory segmentation method for the pre-trip phase needed further validation. When a vehicle leaves a measurable yaw mark at the start of its pre-trip phase it might be possible to compare estimates from the three-phase model to those obtained using the critical speed method, and this paper describes Bayesian reconstruction of two such cases. For the first, the 95 percent confidence interval for the case vehicle's initial speed, estimated using the critical speed method, was (64 mph, 81 mph) while the 95 percent confidence interval via the three-phase model was (66 mph, 79 mph).
2015-04-14
Technical Paper
2015-01-1703
John D. Bullough
Abstract Assessing the safety impacts of vehicle forward lighting is a challenge because crash data do not always contain details necessary to ascertain the role, if any, of lighting in crashes. The present paper describes several approaches to evaluating the safety impacts of lighting using naturalistic driving data. Driving behavioral data and descriptive narratives of crashes and near-miss incidents might provide new opportunities to understand how forward lighting improves traffic safety.
2015-04-14
Technical Paper
2015-01-1700
John D. Bullough
Abstract Warning lights and beacons on service vehicles such as maintenance trucks, tow trucks, utility service vehicles and delivery vehicles are an important line of defense for the workers who operate them. These flashing lights can also contribute to visual chaos making it difficult to navigate through a work zone location. Research on the flashing configuration and spatial and temporal coordination of warning lights that could adapt to ambient conditions and situations is described, leading to recommendations for preliminary performance specifications
2015-04-14
Technical Paper
2015-01-1705
Miguel Hurtado, Amine Taleb-Bendiab, Julien Moizard, Patrice M. Reilhac, Heinz Mattern
Abstract Current market trend indicates an increased interest in replacing mirrors by camera monitor systems (CMS) to reduce CO2 emissions and to improve visibility of surrounding environment to the driver. A CMS is an advanced system composed of an electronic imager, a display, and an intelligent electronic control unit intended to provide at least the same level of functionality of legally prescribed mirrors. A CMS must also take into consideration several factors in the designed system to satisfy an overall system magnification and system resolution. Some factors pertain to the camera, and display inside the cockpit, but some other are related to the physical constraints of the human operator, i.e. visual acuity, height, etc. In this paper, we demonstrate that there exists a fundamental nonlinear equation for a given CMS encompassing factors that influence the performance of the system.
2015-04-14
Technical Paper
2015-01-1704
Dee Kivett, John Smith
Several emerging technologies hold great promise to improve the 360-degree awareness of the heavy vehicle driver. However, current industry-standard evaluation methods do not measure all the comprehensive factors contributing to the overall effectiveness of such systems. As a result, industry is challenged to evaluate new technologies in a way that is objective and allows the comparison of different systems in a consistent manner. This research aims to explore the methods currently in use, identify relevant factors not presently incorporated in standard procedures, and recommend best practices to accomplish an overall measurement system that can quantify performance beyond simply the field of view of a driver visibility system. We introduce a new metric, “Clarity of View,” that incorporates several important factors for visibility systems including: gap acceptance accuracy, image detection time, and distortion.
2015-04-14
Technical Paper
2015-01-1707
Ravi Ranjan, Shivaswaroop Parameswaraiah
Abstract 1 Glare is subjective and can either cause disability or discomfort in eyes. Thus glare during driving especially at night is a serious concern and must be addressed. No commercial product exists to counter the glare, though there had been some academic progress in realizing a solution. The paper presents two promising technologies that help in reducing the oncoming vehicle glare. The system comprises of a vision based identification of glare source. A pixelated transparent film/glass with dynamically controllable transmittance is placed between the driver and source. By changing the transparency locally, glare is avoided without affecting the overall visibility. The paper details on lab results and feasibility of two proposed solution i.e. Use of a matrix of electro chromic films such that each element can be individually controlled and use of transparent LCD such that each pixel is controlled for its transparency.
2015-04-14
Technical Paper
2015-01-1614
Yijung Chen, Derek Board, Omar Faruque, Cortney Stancato, James Cheng, Nikhil Bolar, Sreevidhya Anandavally
Abstract The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy (DOE) project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while achieving frontal crash test performance comparable to the baseline vehicle. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design comprised of commercially available materials and production processes, achieved a 364 kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0 liter three-cylinder engine, leading to the potential for reduced environmental impact and improved fuel economy.
2015-04-14
Journal Article
2015-01-1595
Kristoffer Lundahl, Chih Feng Lee, Erik Frisk, Lars Nielsen
Abstract Rollover has for long been a major safety concern for trucks, and will be even more so as automated driving is envisaged to becoming a key element of future mobility. A natural way to address rollover is to extend the capabilities of current active-safety systems with a system that intervenes by steering or braking actuation when there is a risk of rollover. Assessing and predicting the rollover is usually performed using rollover indices calculated either from lateral acceleration or lateral load transfer. Since these indices are evaluated based on different physical observations it is not obvious how they can be compared or how well they reflect rollover events in different situations. In this paper we investigate the implication of the above mentioned rollover indices in different critical maneuvers for a heavy 8×4 twin-steer truck.
2015-04-14
Technical Paper
2015-01-1465
Sho Nikaido, Shota Wada, Yasuhiro Matsui, Shoko Oikawa, Toshiya Hirose
Abstract Although traffic accidents in Japan involving bicycles have been decreasing yearly, more than 120,000 per year still occur. Few data exist regarding the mechanisms underlying bicycle accidents occurring at intersections. Such dangerous situations form the backdrop of the warning and automatic braking systems being developed for motor vehicles. By clarifying cyclist behavioral characteristics at crucial times, it may be possible to introduce a similar warning system for cyclists as a countermeasure to reduce accidents. The objective of this study is to clarify the mechanism of accidents involving bicycles and to obtain useful data for the development of a warning system for cyclists. A video camera and software investigated and analyzed cyclists' speed and trajectory at an intersection where many accidents occur. Cyclists entering the intersection from one direction were recorded.
2015-04-14
Technical Paper
2015-01-1466
Dietmar Otte, Thorsten Facius, Birgit Wiese
Abstract The overall number of severely injured participants and fatalities in road traffic accidents has decreased enormously during the last decades especially in Europe, but casualties in the group of riders of motorcycles have only decreased in a smaller percentage. In countries of Asia the numbers of motorcycle casualties are increasing regarding the popularity of motorcycle riding. The aim of this study is to analyze the current accident situation of motorcycles in Germany with severely injured and killed riders of motorcycles with cubic capacity > 125 cm3 in Germany, to identify the characteristics in injury mechanisms and accident constellations to find countermeasures to be suggested for worldwide accident avoidance and injury reduction. The study was carried out on the basis of accident data of 1,493 drivers of motorcycles involved in traffic accidents in Germany.
2015-04-14
Technical Paper
2015-01-1468
Radovan Miucic, Xinzhou Wu, Sue Bai, James Misener
Abstract This paper explores use of Dedicated Short Range Communication (DSRC) to improve safety by exchanging messages between vehicles and pedestrians. In recent years, the percentage of pedestrian fatalities has risen in the US compared to other traffic crash victims. In 2012 alone there were 4743 pedestrian fatalities, 14.1 percent of the total fatalities. DSRC is the next chapter of the advanced vehicle safety systems, and the application of this high-availability, low-latency broadcast communication technology across the US vehicle fleet can reduce the total number of fatalities and injuries. Although safety applications originally envisioned for DSRC were focused on the vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communication we show that it is extensible to vehicle-to-pedestrian (V2P) safety communication.
2015-04-14
Technical Paper
2015-01-1467
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Munenori Shinada
Abstract Logistic regression analysis for accident cases of NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) clearly shows that the extent and the degree of pedestrian's lower extremity injury depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, bumper to knee ratio, bumper lead angle, age of the pedestrian, and posture of the pedestrian at the time of impact. The pedestrian population is divided in 3 groups, equivalent to small-shorter, medium-height and large-taller pedestrian with respect to the “pedestrian to BLE height-ratio” in order to quantify the degree of influence of lower leg injuries in each group. Large adult male finite element model (95th percentile male: 190 cm and 103 kg) was developed by morphing the Japan Automobile Manufacturers Association (JAMA) 50th percentile male.
2015-04-14
Technical Paper
2015-01-1461
Dietmar Otte
Abstract During most pedestrian-vehicle crashes the car front impacts the pedestrian and the whole body wraps around the front shape of the car. This influences the head impact on the vehicle. Meanwhile the windscreen is a major impact point and tested in NCAP conditions. The severity of injuries is influenced by car impact speed; type of vehicle; stiffness and shape of the vehicle; nature of the front (such as the bumper height, bonnet height and length, windscreen frame); age and body height of the pedestrian; and standing position of the pedestrian relative to the vehicle front. The so called Wrap Around Distance WAD is one of the important measurements for the assessment of protection of pedestrians and of bicyclists as well because the kinematic of bicyclists is similar to that of pedestrians. For this study accidents of GIDAS were used to identify the importance of WAD for the resulting head injury severity of pedestrians and bicyclists.
Viewing 121 to 150 of 16153

Filter