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The Effect of Lane Departure Warning Systems on Cross-Centerline CrashesHolmes, David Alexander 16 May 2018 (has links)
Cross-centerline crashes occur rarely in the United States but are especially severe. This type of crash is characterized by one vehicle departing over a centerline and encountering a vehicle traveling in the opposite direction. In recent years, automakers have started developing and implementing lane departure warning (LDW) on newer vehicles. This system provides the potential to reduce or significantly impact the frequency of cross-centerline crashes. The objective of this thesis was to estimate the potential crash and injury benefits of a LDW system if installed on every vehicle in the US fleet.
This research includes the following 1) a characterization of cross-centerline crashes in the United States today with current and future prevention methods, 2) a reconstruction methodology used for all crashes including rollovers and heavy vehicles, and 3) a simulation model and approach method used to estimate potential benefits of LDW systems on cross-centerline crashes.
Cross over to left crashes account for only 4% of non-junction non-interchange crashes but account for 44% of serious injury crashes of the same type. As part of this research, 42 cross-centerline crashes were reconstructed and simulated as if they had a LDW system installed. Accounting for driver capability to react to a LDW alert, crash reduction benefits ranged from 22 – 30%.Using injury risk curves, the probability of experiencing a MAIS2+ injury in a cross-centerline crash was reduced by 29% when using a LDW system. / Master of Science / Cross over to left crashes occur rarely but are typically very severe. Cross over to left crashes include wrong side of road crashes, cross over to left due to loss of control, and cross over to left over centerline crashes, also known as cross-centerline crashes. Cross-centerline crashes are typically very severe due to the high closing speeds of both vehicles. Lane departure warning (LDW) is a safety system developed by auto manufacturers designed to help drivers stay in their travel lane. Upon leaving your lane without using a turn signal, a LDW system will provide an alert to warn you to stay in your lane. While LDW systems have been found to be effective for preventing road departure crashes, there have been few studies on their effectiveness for preventing cross-centerline crashes.
The research objective of this thesis was to estimate the number of crashes in the United States that would be avoided if every vehicle was equipped with a LDW system. It was also of interest to determine the number of front-row occupants who would not experience a greater than moderate level of injury (MAIS2+) with a LDW system installed.
To form the dataset, 42 crashes were initially selected, reconstructed, and simulated as if the encroaching vehicle had a LDW system installed. The speed profile of the vehicle was constructed using crash simulation software and an approach model in order to predict the vehicle speed prior to the crash. Driver capability to react to a LDW warning was also accounted for resulting in a range of benefits. With a LDW system installed, 22- 30% of cross-centerline crashes would be avoided. The probability of experiencing a MAIS2+ injury was also reduced by 29% when a LDW system was installed.
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Analyse des Spurwechselverhaltens anhand von Trajektoriendaten amerikanischer AutobahnenKreisel, Andreas 25 May 2016 (has links) (PDF)
In dieser Arbeit wird das Verhalten der Fahrer vor, während und nach dem Spurwechsel anhand eines Datensatzes untersucht. Dieser wurde im Jahr 2006 in den USA erhoben und enthält die genauen Trajektoriendaten für jedes Fahrzeug.
Es konnte gezeigt werden, dass schnellere Fahrzeuge ihren Spurwechsel auch schneller abschließen. Es ist auch erkennbar, dass bei einem Wechsel nach rechts kein kleinerer Abstand zum Vorderfahrzeug in Kauf genommen wird. Eine Untersuchung der freiwilligen und notwendigen Wechsel konnte keine signifikanten Unterschiede feststellen.
Im zweiten Teil der Auswertung wurden die Spurwechselentscheidungen mittels eines generellen Modells und MOBIL untersucht. Die einzusetzenden Werte wurden mit den Fahrzeugfolgemodellen OVM, Gipps-Modell und IDM erzeugt. Die Entscheidungen der Spurwechselmodelle fielen nur selten so aus, wie sie in der Realität getroffen wurden. Damit werden die Modelle ihrem eigenen Anspruch nicht gerecht, die Realität möglichst gut nachzubilden. / The topic of this master thesis is the investigation of the behaviour of the drivers before, during and after lane changes on highways. For this purpose a data set of the I-80 in the USA was used. It was collected in 2006 and contains the trajectories of all vehicles.
It could be shown that faster cars even do a faster lane change. The drivers also do not accept a smaller gap to the preceding car after a lane change to the right. A comparison of voluntary and necessary lane changes did not show significant differences.
In the second part of the analysis the lane change decision was examined using a general model and MOBIL. The data to be inserted were generated using the car-following models OVM, Gipps-model and IDM. But the outcomes of the lane change models only rarely matched reality. Therefore, the models did not fulfill their own standards to picture the existing reality.
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Ground Target Tracking with Multi-Lane ConstraintChen, Yangsheng 15 May 2009 (has links)
Knowledge of the lane that a target is located in is of particular interest in on-road surveillance and target tracking systems. We formulate the problem and propose two approaches for on-road target estimation with lane tracking. The first approach for lane tracking is lane identification based ona Hidden Markov Model (HMM) framework. Two identifiers are developed according to different optimality goals of identification, i.e., the optimality for the whole lane sequence and the optimality of the current lane where the target is given the whole observation sequence. The second approach is on-road target tracking with lane estimation. We propose a 2D road representation which additionally allows to model the lateral motion of the target. For fusion of the radar and image sensor based measurement data we develop three, IMM-based, estimators that use different fusion schemes: centralized, distributed, and sequential. Simulation results show that the proposed two methods have new capabilities and achieve improved estimation accuracy for on-road target tracking.
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Calibração de simuladores microscópicos de tráfego através de medidas macroscópicas / Calibration of microscopic traffic simulators using macroscopic measuresBethonico, Felipe Costa 19 April 2016 (has links)
Os simuladores de tráfego são programas computacionais que, através de diversos modelos, tentam simular o tráfego, o comportamento dos motoristas, o desempenho dos veículos, entre outros aspectos que envolvem uma rede viária. Estes modelos precisam ser calibrados para representar as condições de um determinado local. O objetivo da pesquisa foi propor um método de calibração de um microssimulador de tráfego através de dados coletados por estações de monitoramento. O estudo de caso foi realizado através do simulador VISSIM para um trecho do Rodoanel Mário Covas (SP-021), utilizando um algoritmo genético (AG). A calibração envolveu, além dos parâmetros comportamentais dos sub-modelos de car-following e lane-change, o ajuste das distribuições de velocidade desejada dos veículos e um método para simulação do congestionamento. A função fitness do AG foi baseada em três medidas de desempenho: uma que comparava gráficos de fluxo-velocidade simulados e observados e outras duas que comparavam a distribuição do volume de tráfego e o percentual de veículos comerciais por faixa de tráfego. Os resultados mostraram que a medida mais apropriada para a comparação dos gráficos foi a distância de Hausdorff modificada (MHD). A medida MHD também foi fundamental para garantir a ciência do método de simulação de congestionamento de tráfego proposto. O modelo calibrado foi validado usando dados de tráfego coletados em dias diferentes, pela mesma estação de monitoramento. / Traffic simulators are computer programs that, through various models, try to simulate traffic, driver behavior, vehicle performance, and other aspects involved in a road network. These models need calibration to represent local conditions satisfactorily. The objective of the research was to propose a method for the calibration of a traffic microsimulator based on traffic data collected by monitoring stations. To demonstrate the feasibility of the proposed approach, a case study was performed calibrating the simulator VISSIM for a section of Rodoanel Mario Covas (SP-021) using a genetic algorithm (GA). The calibration focused on behavioral parameters for car-following and lane-change submodels, as well as on the desired speed distributions of vehicles and on a method to simulate congestion. The GA fitness function was based on three performance measures: one that compared simulated and observed speed-flow plots, and two that compared the distribution of traffic volume and truck volumes across traffic lanes, respectively. The results showed that the most appropriate measure for comparison of the graphs was the modified Hausdor distance (MHD). MHD was also important to ensure the efficiency of the method used to simulate traffic congestion. The calibrated model was validate using traffic data collected on different days, by the same monitoring station.
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TCP/IP sobre LANE e o seu impacto prático na rede local / TCP/IP over LANE and its practical impact on a local area networkKakuda, Claudio Massaki 11 August 2006 (has links)
Esta dissertação descreve os métodos, medidas e análises feitas para otimizar a rede de comunicação de dados do Instituto de Física de São Carlos. As tecnologias e protocolos utilizados na rede são apresentados. Especial atenção é dada a análise do desempenho de VLANs utilizando inicialmente o protocolo LANE no núcleo ATM da rede. Neste caso a rede é composta de switches ATM e ATM-Ethernet. Medidas comparativas foram realizadas com a utilização da tecnologia Fast Ethernet no backbone, que possui uma capacidade de transmissão relativamente próxima da ATM de 155Mbps. Melhores resultados obtidos com a implementação de sub-redes maiores, reduzindo em um numero menor de sub-redes, são discutidos e apresentados. Análises estatísticas baseadas apenas no tempo de resposta da rede são apresentados para avaliar o desempenho das alterações efetuadas nas configurações da rede. Mesmo que o tráfego tenha aumentado muito durante esses anos e que vários serviços tenha sido agregados a esta rede, foi possível adequar o desempenho as novas necessidades beneficiando-se da evolução tecnológica que os equipamentos de rede de dados trouxeram ao IFSC. / This work describes the methods, measures and analyses performed aiming to optimize the data communication network from the Physics Institute of Sao Carlos as well as the technologies and protocols used in the network recently. Special care is given to the analysis of the VLANs performance using, initially, the LANE protocol over ATM which has its core based on pure ATM and ATM-Ethernet switches. Comparative measures had been carried out using a backbone working on a Fast Ethernet technology, which seems to have a very close transmission rate from the ATM 155Mbps. This work also discusses best results acquired with the implementation of larger networks reducing the number of subnetworks, statistical analyses based on time delay of the network in order to evaluate the performance of the changes made on its configuration. Even though the traffic from the Institute has been increased over these years and several services have been added to the network, it was completely possible to adapt the performance to the needs, using the benefits of the technological evolution which the network equipments had brought to the Institute.
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Calibração de simuladores microscópicos de tráfego através de medidas macroscópicas / Calibration of microscopic traffic simulators using macroscopic measuresFelipe Costa Bethonico 19 April 2016 (has links)
Os simuladores de tráfego são programas computacionais que, através de diversos modelos, tentam simular o tráfego, o comportamento dos motoristas, o desempenho dos veículos, entre outros aspectos que envolvem uma rede viária. Estes modelos precisam ser calibrados para representar as condições de um determinado local. O objetivo da pesquisa foi propor um método de calibração de um microssimulador de tráfego através de dados coletados por estações de monitoramento. O estudo de caso foi realizado através do simulador VISSIM para um trecho do Rodoanel Mário Covas (SP-021), utilizando um algoritmo genético (AG). A calibração envolveu, além dos parâmetros comportamentais dos sub-modelos de car-following e lane-change, o ajuste das distribuições de velocidade desejada dos veículos e um método para simulação do congestionamento. A função fitness do AG foi baseada em três medidas de desempenho: uma que comparava gráficos de fluxo-velocidade simulados e observados e outras duas que comparavam a distribuição do volume de tráfego e o percentual de veículos comerciais por faixa de tráfego. Os resultados mostraram que a medida mais apropriada para a comparação dos gráficos foi a distância de Hausdorff modificada (MHD). A medida MHD também foi fundamental para garantir a ciência do método de simulação de congestionamento de tráfego proposto. O modelo calibrado foi validado usando dados de tráfego coletados em dias diferentes, pela mesma estação de monitoramento. / Traffic simulators are computer programs that, through various models, try to simulate traffic, driver behavior, vehicle performance, and other aspects involved in a road network. These models need calibration to represent local conditions satisfactorily. The objective of the research was to propose a method for the calibration of a traffic microsimulator based on traffic data collected by monitoring stations. To demonstrate the feasibility of the proposed approach, a case study was performed calibrating the simulator VISSIM for a section of Rodoanel Mario Covas (SP-021) using a genetic algorithm (GA). The calibration focused on behavioral parameters for car-following and lane-change submodels, as well as on the desired speed distributions of vehicles and on a method to simulate congestion. The GA fitness function was based on three performance measures: one that compared simulated and observed speed-flow plots, and two that compared the distribution of traffic volume and truck volumes across traffic lanes, respectively. The results showed that the most appropriate measure for comparison of the graphs was the modified Hausdor distance (MHD). MHD was also important to ensure the efficiency of the method used to simulate traffic congestion. The calibrated model was validate using traffic data collected on different days, by the same monitoring station.
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Detection of Driver Unawareness Based on Long- and Short-term Analysis of Driver Lane KeepingWigh, Fredrik January 2007 (has links)
<p>Many traffic accidents are caused by driver unawareness. This includes fatigue, drowsiness and distraction. In this thesis two systems are described that could be used to decrease the number of accidents. In the first part of this thesis a system using long-term information to warn drivers suffering from fatigue is developed. Three different versions with different criteria are evaluated. The systems are shown to handle more then 60% of the cases correctly.</p><p>The second part of this thesis examines the possibilities of developing a warning system based on the predicted time-to-lane crossing, TLC. A basic TLC model is implemented and evaluated. For short time periods before lane crossing this may offer adequate accuracy. However the accuracy is not good enough for the model to be used in a TLC based warning system to warn the driver of imminent lane departure.</p>
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Asthma prevalence in school children in Lane County, OregonBerry, Cheryl Anne 01 May 1998 (has links)
Asthma prevalence in children under age 18 has risen steadily in the U.S. since the mid-1970s. Most researchers attribute this increase to air pollutants, socioeconomic status or
urban residence. This study examined asthma prevalence in Lane County, Oregon, using
children's asthma hospital discharges (1990-1995), and data from 10 of 16 school
districts. The overall asthma prevalence in Lane County was 5.8%, ranging from 1.9%
(coastal Siuslaw District) to 10% (urban, industrial Bethel District). Asthma prevalence
during 1988-1997 was examined for the largest school district, Eugene 4J (43% of the
total study population). Eugene 4J is divided into four regions: North, South, Churchill,
and Sheldon. The largest asthma prevalence increase during this time was detected in
North Region (2.5%-8%), while the overall district prevalence nearly doubled (3.3%-6.2%). No correlation was found between socioeconomic status and asthma prevalence,
and there was not a consistent pattern between asthma prevalence and location of each
school district (urban vs. rural). Two out of the three urban school districts had higher
asthma prevalence than five of the rural school districts. However, three school districts
did not follow this pattern, either being lower than expected for an urban area or higher
than expected for a rural area. Asthma hospitalization rates increased for most children
between 1990 and 1995, with a 20-fold increase for ages 15-19 years. The results of this
study show an increase in prevalence and severity of asthma in school children in Lane
County. Further studies are warranted to investigate the contribution that geography,
meteorology, and proximity to industry have in asthma prevalence in Lane County. / Graduation date: 1999
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Monitoring potential groundwater contamination due to agricultural production in Lane County, OregonGatchell, Lance O. 06 June 1996 (has links)
Graduation date: 1997
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Effects of stream restoration on macroinvertebrate communities in an Oregon Coast Range systemChristensen, M. Jo 09 February 1996 (has links)
Stream-restoration projects are usually designed to improve habitat quality for fishes.
These projects manipulate flow patterns, substrate distribution, and amount and
placement of large woody debris. Consequently, they also affect the size and composition
of the aquatic macroinvertebrate community. This research evaluates two types of fish
habitat restoration: off-channel structures (alcoves) and in-channel structures (log weirs).
I compared macroinvertebrate habitats and communities in natural and artificial alcoves
in Upper and South Fork Lobster Creeks, Lane Co., and examined the effects of log
weirs on in-channel habitat diversity, community composition, drift patterns, and fish
consumption of macroinvertebrates. Macroinvertebrate samples were collected from
artificial and natural alcoves using hand pumps and D-nets. Within the channel,
macroinvertebrates were collected from restored and unrestored reaches with a Hess
sampler and using a stratified random sampling scheme. Forty-eight hour invertebrate
drift samples were obtained at outlets of log-weir pools. Stomach contents were obtained
from coho salmon (Oncorhynchus kisutch) and cutthroat trout (O. clarki) in restored
reaches.
Although natural alcoves differed from artificial in location within the floodplain,
morphology, permanence, and degree of interaction with the stream channel, both alcovetypes
provided similar habitats and contained similar macroinvertebrate communities.
Average densities and diversity within the alcoves depended on habitat and time of year.
Average densities were higher in artificial than in natural. Alcoves contained 29% of
species richness within Upper Lobster Creek.
Within the stream channel, the diversity of macroinvertebrate habitat was lower in
restored than in unrestored sections. Log weirs were associated with reduced taxonomic
and functional feeding-group diversity. Composition of drift was not significantly
different in restored and unrestored areas; however, drift densities were significantly
lower in restored reaches. Diets of fishes in restored areas were composed primarily of
organisms produced from outside restored areas. Although in-channel structures may
enhance physical habitat for fishes, they may alter or reduce the availability of food for
fishes feeding on drifting invertebrates.
Recommendations are given for improving the design of stream restoration projects
with respect to macroinvertebrates; however stream restoration should focus on restoring
whole-system integrity and function, instead of targeting just one or two types of
organisms. / Graduation date: 1996
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