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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
2015-01-1427
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
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
2015-01-1429
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
2015-01-1430
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
2015-01-1432
Jeffrey Aaron Suway, Judson Welcher
Abstract Accident reconstruction experts are often asked to evaluate the visibility and conspicuity of objects in the roadway. It is common for objects placed in or along the roadway, vehicles, and required by Federal Motor Vehicle Safety Standard (FMVSS) No. 108 for certain vehicles and trailers, to have red and white DOT-C2 retroreflective tape installed on several locations. Retroreflective tape is designed to reflect light back towards the light source at the same entrance angle. The authors' literature review revealed that there have been no publications quantifying the performance of commercially available DOT-C2 retroreflective tape with real world vehicles. Therefore, without additional study, an accident reconstruction expert cannot know exactly how a specific type of compliant tape would perform beyond the minimum federal requirements. In the current research, the performance of white and red DOT-C2 retroreflective tape is quantified.
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
2015-01-1437
Tony R. Laituri, Raed E. El-Jawahri, Scott Henry, Kaye Sullivan
Abstract In the present study, various risk curves for moderate-to-fatal head injury (AIS2+) were theoretically assessed by comparing model-based injury rates with field-based injury rates. This was accomplished by applying the risk curves in corresponding field models. The resulting injury rates were considered from two perspectives: aggregate (0-56 kph events) and point-estimate (higher-speed, barrier-like events). Four risk curves were studied: a HIC15-based curve from Mertz et al. (1997), a BRIC-based curve from Takhounts et al. (2011), a BrIC-based curve from Takhounts et al. (2013) and a Concussion-Correlate-based curve from Rowson et al. (2013). The field modeling pertained to adult drivers in 11-1 o'clock, towaway, full-engagement frontal crashes in the National Automotive Sampling System (NASS, calendar years = 1993-2012), and the model-year range of the passenger vehicles was 1985-2010.
2015-04-14
Technical Paper
2015-01-1439
Toshiyuki Yanaoka, Yasuhiro Dokko, Yukou Takahashi
Abstract The high frequency of fatal head injuries is one of the important issues in traffic safety, and Traumatic Brain Injuries (TBIs) without skull fracture account for approximately half of them in both occupant and pedestrian crashes. In order to evaluate vehicle safety performance for TBIs in these crashes using anthropomorphic test dummies (ATDs), a comprehensive injury criterion calculated from the rotational rigid motion of the head is required. While many studies have been conducted to investigate such an injury criterion with a focus on diffuse brain injuries in occupant crashes, there have been only a limited number of studies focusing on pedestrian impacts. The objective of this study is to develop a comprehensive injury criterion based on the rotational rigid body motion of the head suitable for both occupant and pedestrian crashes.
2015-04-14
Journal Article
2015-01-1441
Yibing Shi, Guy Nusholtz
Abstract Two methods of assessing the similarity of a set of impact test signals have been proposed and used in the literature, which are cumulative variance-based and cross correlation-based. In this study, a normalized formulation unites these two approaches by establishing a relationship between the normalized cumulative variance metric (v), an overall similarity metric, and the normalized magnitude similarity metric (m) and shape similarity metric (s): v=1 − m · s. Each of these ranges between 0 and 1 (for the practical case of signals acquired with the same polarity), and they are independent of the physical unit of measurement. Under generally satisfied conditions, the magnitude similarity m is independent of the relative time shifts among the signals in the set; while the shape similarity s is a function of these.
2015-04-14
Technical Paper
2015-01-1442
Wolfgang Sinz, Jörg Moser, Christoph Klein, Robert Greimel, Karsten Raguse, Class Middendorff, Christina Steiner
Abstract Precise three-dimensional dummy head trajectories during crash tests are very important for vehicle safety development. To determine precise trajectories with a standard deviation of approximately 5 millimeters, three-dimensional video analysis is an approved method. Therefore the tracked body is to be seen on at least two cameras during the whole crash term, which is often not given (e.g. head dips into the airbag). This non-continuity problem of video analysis is surmounted by numerical integration of differential un-interrupted electrical rotation and acceleration sensor signals mounted into the tracked body. Problems of this approach are unknown sensor calibration errors and unknown initial conditions, which result in trajectory deviations above 10 centimeters.
2015-04-14
Technical Paper
2015-01-1443
Morteza Seidi, Marzieh Hajiaghamemar, James Ferguson, Vincent Caccese
Abstract Falls in the elderly population is an important concern to individuals and in the healthcare industry. When the head is left unprotected, head impact levels can reach upwards of 500 g (gravitational acceleration), which is a level that can cause serious injury or death. A protective system for a fall injury needs to be designed with specific criteria in mind including energy protection level, thickness, stiffness, and weight among others. The current study quantifies the performance of a protective head gear design for persons prone to falls. The main objective of this paper is to evaluate the injury mitigation of head protection gear made from a patented system of polyurethane honeycomb and dilatant materials. To that end, a twin wire fall system equipped with a drop arm that includes a Hybrid-III head/neck assembly was used. The head was instrumented with an accelerometer array.
2015-04-14
Technical Paper
2015-01-1444
Ada H. Tsoi, John Hinch, H. Gabler
Abstract Event data recorders (EDRs) must survive regulatory frontal and side compliance crash tests if installed within a car or light truck built on or after September 1, 2012. Although previous research has shown that EDR data are surviving these tests, little is known about whether EDRs are capable of surviving collisions of higher delta-v, or crashes involving vehicle fire or immersion. The goal of this study was to determine the survivability of light vehicle EDRs in real world fire, immersion, and high change in velocity (delta-v) cases. The specific objective was to identify the frequency of these extreme events and to determine the EDR data download outcome when subject to damage caused by these events. This study was performed using three crash databases: the Fatality Analysis Reporting System (FARS), the National Automotive Sampling System / Crashworthiness Data System (NASS/CDS), and the National Motor Vehicle Crash Causation Survey (NMVCCS).
2015-04-14
Technical Paper
2015-01-1446
Timothy P. Austin, David P. Plant, Joseph E. LeFevre
Abstract The use of Heavy Vehicle Event Data Recorders (HVEDRs) in collision analysis has been well recognized in past research. Numerous publications have been presented illustrating data accuracy both in normal operating conditions as well as under emergency braking conditions. These data recording devices are generally incorporated into Electronic Control Modules (ECMs) for engines or Electronic Control Units (ECUs) for other vehicular components such as the Anti-Lock Brake System. Other research has looked at after-market recorders, including publically-available Global Positioning System (GPS) devices and fleet management tools such as Qualcomm. In 2009, the National Fire Protection Association (NFPA) incorporated a Vehicle Data Recorder (VDR) component into their Standard for Automotive Fire Apparatus. The purpose of this was to “…capture data that can be used to promote safe driving and riding practices.”
2015-04-14
Technical Paper
2015-01-1445
Wesley Vandiver, Robert Anderson, Isaac Ikram, Bryan Randles, Christopher Furbish
Abstract The 2012 Kia Soul was manufactured with an Airbag Control Module (ACM) with an Event Data Recorder (EDR) function to record crash related data. However, 2013 is the first model year supported by the download tool and software manufactured for Kia vehicles and distributed by GIT America, Inc. Even with the same make and model, using the Kia EDR tool to image data from an unsupported model year calls into question whether some or any of the data has been properly translated. By way of example, a method for evaluating the usability of the crash related data obtained via coverage spoofing a 2012 Kia Soul is presented. Eight vehicle-to-barrier crash tests were conducted in a 2012 Kia Soul. The Kia EDR tool was utilized to retrieve crash data from the vehicle's EDR following each test by choosing the software translation settings for a 2013 Kia Soul. The recorded and translated crash data for those tests were analyzed and compared to on-board instrumentation.
2015-04-14
Technical Paper
2015-01-1448
Lee Carr, Robert Rucoba, Dan Barnes, Steven Kent, Aaron Osterhout
Abstract With commercial availability of the Bosch Crash Data Retrieval Tool (CDR), the information stored in vehicle Event Data Recorders (EDRs) has increasingly been used to supplement traditional traffic crash data collection and reconstruction methods, allowing enhanced confidence levels in transportation safety research. The objective of this study was to assess the accuracy and reliability of EDR data images obtained with the Bosch CDR tool by comparing them to a known crash impulse. Multiple EDRs and necessary sensor arrays were mounted on a HYGE™ acceleration-type crash simulation sled system at various orientations representing different principal direction of force (PDOF) angles and subjected to controlled “crash” impulses, simulating a “deployment event” (DE) and triggering data to be saved in the EDRs. The data included in each EDR's CDR report was compared to the known conditions of the impulse.
2015-04-14
Technical Paper
2015-01-1447
Hirotoshi Ishikawa, Kunihiro Mashiko, Tetsuyuki Matsuda, Koichi Fujita, Asuka Sugano, Toru Kiuchi, Hirotsugu Tajima, Masaaki Yoshida, Isao Endou
Abstract Event Data Recorders (EDRs) record valuable data in estimating the occupant injury severity after a crash. Advanced Automatic Collision Notification (AACN) with the use of EDR data will determine the potential extent of injuries to those involved in motor vehicle accidents. In order to obtain basic information in injury estimation using EDR data, frontal collisions for 29 vehicles equipped with EDRs were analyzed as a pilot study by retrieving the EDR data from the accident vehicles and collecting the occupant injury data from the database of an insurance company. As a result, the severity of occupant injury was closely related to the Delta V recorded on an EDR. However, there were several cases in which the predicted injury level was overestimated or underestimated by the Delta V. Therefore, caution is required when predicting the level of injury in frontal collisions based upon the Delta V alone.
2015-04-14
Technical Paper
2015-01-1449
Ada H. Tsoi, John Hinch, Michael Winterhalter, H. Gabler
Abstract Event data recorder (EDR) data are currently only required to survive the crash tests specified by Federal Motor Vehicle Safety Standard (FMVSS) 208 and FMVSS 214. Although these crash tests are severe, motor vehicles are also exposed to more severe crashes, fire, and submersion. Little is known about whether current EDR data are capable of surviving these events. The objective of this study was to determine the limits of survivability for EDR data for realistic car crash conditions involving heat, submersion, and static crush. Thirty-one (31) EDRs were assessed in this study: 4 in the pilot tests and 27 in the production tests. The production tests were conducted on model year (MY) 2011-2012 EDRs enclosed in plastic, metal, or a combination of both materials. Each enclosure type was exposed to 9 tests. The high temperature tests were divided into 3 oven testing conditions: 100°C, 150°C, and 200°C.
2015-04-14
Technical Paper
2015-01-1451
Anand Sai Gudlur, Theresa Atkinson
Abstract The current study examined field data in order to document injury rates, injured body regions, and injury sources for persons seated in the second row of passenger vehicles. It was also intended to identify whether these varied with respect to age and restraint use in vehicles manufactured in recent years. Data from the 2007-2012 National Automotive Sampling System (NASS/CDS) was used to describe occupants seated in the second row of vehicles in frontal crashes. Injury plots, comparison of means and logistic regression analysis were used to seek factors associated with increased risk of injury. Restraint use reduced the risk of AIS ≥ 2 injury from approximately 1.8% to 5.8% overall. Seventy nine percent of the occupants in the weighted data set used either a lap and shoulder belt or child restraint system. The most frequently indicated injury source for persons with a MAIS ≥ 2 was “seat, back support”, across restraint conditions and for all but the youngest occupants.
2015-04-14
Technical Paper
2015-01-1452
Kathleen DeSantis Klinich, Kyle Boyle, Laura Malik, Miriam Manary, Jingwen Hu
This study documented the position and orientation of child restraint systems (CRS) installed in the second rows of vehicles, creating a database of 486 installations. Thirty-one different CRS were evaluated, selected to provide a range of manufacturers, sizes, types, and weight limits. Eleven CRS were rear-facing only, fourteen were convertibles, five were combination restraints, and one was a booster. Ten top-selling vehicles were selected to provide a range of manufacturers and body styles: four sedans, four SUVS, one minivan, and one wagon. CRS were marked with three reference points on each moving component. The contours and landmarks of each CRS were first measured in the laboratory. Vehicle interior contours, belt anchors, and LATCH anchors were measured using a similar process. Then each CRS was installed in a vehicle using LATCH according to manufacturers' directions, and the reference points of each CRS component were measured to document the installed orientation.
2015-04-14
Technical Paper
2015-01-1456
Mani Ayyakannu, Latha Subbiah, Mohammed Syed
Abstract Automotive knee bolster requirements have changed substantially in recent years due to expanded safety requirements. A three-piece cellular structural knee bolster assembly has been evolved to meet this matrix of requirements while being extremely lightweight (as low as 0.7 Kg), low in cost and easily tunable to work in various car/truck programs. The energy absorber is the primary component of this assembly and allows for a range of occupant sizes and weights to be restrained (from 50 Kg/152 cm 5th percentile female to 100 Kg/188cm 95th percentile male occupants). The evolution of this knee bolster assembly design is described using crush analysis, component testing to validate the crush analysis, instrument panel assembly level analysis with occupant models and sled tests. Steel and aluminum versions of this knee bolster are compared - in terms of weight, cost, design tunability for various crash conditions, structural stiffness etc.
2015-04-14
Technical Paper
2015-01-1457
Aditya Belwadi, Richard Hanna, Audrey Eagle, Daniel Martinez, Julie Kleinert, Eric Dahle
Abstract Automotive interior design optimization must balance the design of the vehicle seat and occupant space for safety, comfort and aesthetics with the accommodation of add-on restraint products such as child restraint systems (CRS). It is important to understand the range of CRS dimensions so that this balance can be successfully negotiated. CRS design is constantly changing. In particular, the introduction of side impact protection for CRS as well as emphasis on ease of CRS installation has likely changed key design points of many child restraints. This ever-changing target creates a challenge for vehicle manufacturers to assure their vehicle seats and occupant spaces are compatible with the range of CRS on the market. To date, there is no accepted method for quantifying the geometry of child seats such that new designs can be catalogued in a simple, straightforward way.
2015-04-14
Technical Paper
2015-01-1455
Kenshi Torikai, Hitoshi Higuchi, Kazuhiro Seki
Abstract The reaction force of a traditional passenger airbag tends to reduce after the initial inflation and before contact with the occupant, since the vent structure discharging the internal gas is always open. A potential means to prevent this drop in the airbag reaction force includes the addition of a variable vent structure which keeps the vent hole closed until occupant contact to maintain the airbag internal pressure and then opens to vent gas after the contact. However, variable vent structures may involve issues from a complicated structure due to additional parts in its construction. The goal of this study was to develop a simplified variable vent structure. A slit-type vent structure was investigated. This structure incorporates no additional parts to a conventional airbag with a hole-type vent. Static deployment tests and impactor tests were conducted to measure the effect of the slit-type vent structure and to compare it with the conventional airbag.
2015-04-14
Technical Paper
2015-01-1453
Jingwen Hu, Kurt Fischer, Paul Lange, Angelo Adler
Abstract In this study, two sled series were conducted with a sled buck representing a compact vehicle. The first series of tests focused on the effects of crash pulse, impact angle, occupant size, and front seat location on rear seat occupant restraint with a generic rear-seat belt system without pre-tensioner or load limiter. The second series of tests focused on investigating the benefit of using advanced features for rear-seat occupant restraint in the most severe crash condition in the first sled series. The first series of tests include 16 test conditions with two impact angles (0° and 15°), two sled pulse (soft and severe), and four ATD sizes (HIII 6YO, HIII 5th female, HIII 95th male, and THOR-NT) with two ATDs in each test. The driver seat was located at the mid position, while the front passenger seat was positioned such that a constant distance between the ATD knee and the front seat is achieved.
2015-04-14
Technical Paper
2015-01-1460
Massoud Tavakoli, Janet Brelin-Fornari
Abstract This study was conducted to explore the effect of various combinations of seatbelt-related safety components (namely, retractor pretensioners and load limiting retractors) on the adult rear passenger involved in a frontal collision. The study was conducted on a 50th Male and a 5th Female Hybrid III ATD in the rear seat of a mid-sized sedan. Each ATD was seated in an outboard position with 3-point continuous lap-shoulder belts. On these belts were combinations of pretensioners and load limiters. Since the main objective of this test series was to cross-compare the seatbelt configurations, front seats were not included in the buck in order to avoid uncontrollable variables that would have affected the comparison study if the possibility of contact with the front seat were allowed. Nevertheless, there was a short barrier devised to act as a foot-stop for both ATDs.
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.
2015-04-14
Technical Paper
2015-01-1458
Jia Hu
Abstract A Finite Element (FE) model for analysis of the rear row occupant injury assessment parameters in a frontal crash test was developed by using the LSTC Hybrid III 5th percentile FE dummy model. Three cases were studied using three different rear seatbelt retractor configurations, which were as follows: an ordinary retractor without load limiter or pretensioner (Case 1), a retractor with load limiter only (Case 2), and a retractor with load limiter and pretensioner (Case 3). The simulation results of each of these three cases were compared respectively to the results obtained from two frontal 50-kph full rigid barrier impact tests and one sled test. It turned out that the dummy kinematics and injury assessment parameters of the head, neck, chest, pelvis and femurs were all similar between test and simulation in the three cases. Thus, FE simulation models can be used to predict dummy injury assessment parameters.
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
2015-01-1465
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.
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