Intelligent cruise control (ICC) has the potential to impact both roadway throughput and safety by assisting drivers in maintaining safe headways. This thesis explores this potential through comparisons of ICC to conventional cruise control (CCC) and manual driving. Accordingly, descriptions are given of both CCC and ICC systems. Furthermore, descriptions of ICC evaluation studies and car-following models are presented. The evaluation of ICC is conducted using data collected as part of the Field Operational Test (FOT) performed in Ann Arbor, Michigan. Two levels of analysis are presented in this thesis. The first level of analysis compares the usage of ICC to CCC from a macro level. This study demonstrated that ICC was used more along similar trips. In addition, it was shown that there was no difference in usage of the ON, SET, CANCEL and RESUME buttons. ICC resulted in a higher usage of the ACCEL button and a lower usage of the COAST button compared to CCC. Furthermore, the number of brake interventions while ICC was engaged was higher than CCC. Lastly, the macro-level analysis indicated that there was no difference in the number of near encounters for ICC and CCC. The second analysis makes comparisons at a micro level. The most probable speed, acceleration and headway for each driving mode as well as the probability of using cruise control (based on speed) were determined. The probability of ICC use exceeded CCC use for every freeway speed bin and all but two high-speed arterial speed bins. Finally, a car-following behavior comparison was performed. Manual driving resulted in larger headway values for speeds less than 80 km/h. The ICC speed-headway curve was similar to the CCC speed-headway curve created from high-speed arterial data. The mean headway-speed charts, however, indicated that ICC was more similar to manual driving. Exploration into the specific differences is needed in order to determine the impact of ICC on system safety. / Master of Science

Esta dissertação trata do uso de dispositivos de proteção lateral. Tão importante quando o projeto da rodovia é o projeto do seu entorno, que está diretamente relacionada à segurança dos veículos desgovernados que saem da pista, seja qual for o motivo. O entorno viário deve ser tal que as conseqüências da saída de pista sejam minimizadas, provendo um entorno livre de obstáculos (sejam árvores, postes, terrenos não atravessáveis, etc.) que possam causar danos severos aos seus motoristas, ou utilizando dispositivo de proteção lateral, na impossibilidade de eliminar os obstáculos agressivos, como estratégias complementares da redução dos danos decorrentes das saídas de pista. Na revisão bibliográfica realizada, os conceitos básicos relacionados com proteção lateral, critérios de seleção do tipo de dispositivos e de posicionamento, além da análise das recomendações para os tratamentos de segurança dos dispositivos de drenagem, foram analisados com o objetivo de identificar os estudos que deram origem aos critérios recomendados tradicionalmente (procurando destacar os pontos importantes que esclarecem a aplicação de tais critérios). Além das recomendações tradicionais, também foram analisados os modelos compreensivos, que tratam de forma mais explícita as saídas de pista e a presença dos dispositivos de proteção lateral, considerando o produto de probabilidades condicionais que envolvem as probabilidades de ocorrência de saídas de pista, a probabilidade da saída de pista estar na envoltória do obstáculo, a probabilidade da distância lateral de saída de pista ser suficiente para haver um impacto, a probabilidade de ocorrência de danos ao motorista e seus ocupantes e o custo associados a estes danos. O trabalho de campo desenvolvido analisou a prática do uso de dispositivos de proteção lateral em uma rodovia paulista examinando a observância às recomendações para o uso de dispositivo de proteção lateral e analisando a relação entre as recomendações para o uso de proteção lateral e a ocorrência de acidentes. Os resultados obtidos demonstram que existe carência de aplicação em locais onde os dispositivos são recomendados pelos critérios tradicionais e por critérios ampliados. Estes critérios tradicionais e ampliados foram também comparados baseados nos conceitos de sensibilidade e especificidade, porém, pouco se pode concluir com a utilização dos dados de acidentes obtidos. / This research provides a review of the recommended criteria for the use of lateral safety devices. As important as the roadway design is the roadside design, that is directly related to the safety of vehicles that encroach on the roadside, regardless of the reason. The roadside must mitigate the consequences of run-off-the-road accidents, providing a contiguous area free of obstacles (trees, poles, unrecoverable grounds, etc.) which can cause severe injury to the vehicle occupants, or deploying lateral protective devices, when it is impossible to remove the hazards, both as complementary strategies for reducing damages from run-off-the road accidents. In the literature review, the basic concepts related to roadside protection, the warrants for selecting the type and placement of devices, besides the analysis of recommendation for the safety treatment of drainage devices, were analyzed to identify the studies which gave rise to the traditionally recommended criteria (trying to emphasize the important points that explain the application of such criteria). In addition to traditional recommendations, the comprehensive models were also analyzed, which deals more explicitly with the encroachments and the presence of lateral safety devices as the product of conditional probabilities that involve the encroachment probability, the probability of the encroachment occurring in a hazard envelope, the probability that the vehicle will encroach laterally far enough to reach the hazard, the probability of injury to the driver and passengers, and the cost associated with this injury. Then, the field work analyzed the practice on the use of lateral protective devices in a highway of the State of São Paulo, examining the observance to recommended criteria for using lateral protective devices and analyzing the relationship between the recommendations for the use of lateral protective devices and accident history. The results have shown that there is a deficit in the deployment on sites where the devices were recommended by traditional criteria and improved criteria. This traditional and improved criteria was also compared based on sensitivity and specificity concept, but no valuable conclusions was obtained with the use of accident data available.

Esta dissertação trata do uso de dispositivos de proteção lateral. Tão importante quando o projeto da rodovia é o projeto do seu entorno, que está diretamente relacionada à segurança dos veículos desgovernados que saem da pista, seja qual for o motivo. O entorno viário deve ser tal que as conseqüências da saída de pista sejam minimizadas, provendo um entorno livre de obstáculos (sejam árvores, postes, terrenos não atravessáveis, etc.) que possam causar danos severos aos seus motoristas, ou utilizando dispositivo de proteção lateral, na impossibilidade de eliminar os obstáculos agressivos, como estratégias complementares da redução dos danos decorrentes das saídas de pista. Na revisão bibliográfica realizada, os conceitos básicos relacionados com proteção lateral, critérios de seleção do tipo de dispositivos e de posicionamento, além da análise das recomendações para os tratamentos de segurança dos dispositivos de drenagem, foram analisados com o objetivo de identificar os estudos que deram origem aos critérios recomendados tradicionalmente (procurando destacar os pontos importantes que esclarecem a aplicação de tais critérios). Além das recomendações tradicionais, também foram analisados os modelos compreensivos, que tratam de forma mais explícita as saídas de pista e a presença dos dispositivos de proteção lateral, considerando o produto de probabilidades condicionais que envolvem as probabilidades de ocorrência de saídas de pista, a probabilidade da saída de pista estar na envoltória do obstáculo, a probabilidade da distância lateral de saída de pista ser suficiente para haver um impacto, a probabilidade de ocorrência de danos ao motorista e seus ocupantes e o custo associados a estes danos. O trabalho de campo desenvolvido analisou a prática do uso de dispositivos de proteção lateral em uma rodovia paulista examinando a observância às recomendações para o uso de dispositivo de proteção lateral e analisando a relação entre as recomendações para o uso de proteção lateral e a ocorrência de acidentes. Os resultados obtidos demonstram que existe carência de aplicação em locais onde os dispositivos são recomendados pelos critérios tradicionais e por critérios ampliados. Estes critérios tradicionais e ampliados foram também comparados baseados nos conceitos de sensibilidade e especificidade, porém, pouco se pode concluir com a utilização dos dados de acidentes obtidos. / This research provides a review of the recommended criteria for the use of lateral safety devices. As important as the roadway design is the roadside design, that is directly related to the safety of vehicles that encroach on the roadside, regardless of the reason. The roadside must mitigate the consequences of run-off-the-road accidents, providing a contiguous area free of obstacles (trees, poles, unrecoverable grounds, etc.) which can cause severe injury to the vehicle occupants, or deploying lateral protective devices, when it is impossible to remove the hazards, both as complementary strategies for reducing damages from run-off-the road accidents. In the literature review, the basic concepts related to roadside protection, the warrants for selecting the type and placement of devices, besides the analysis of recommendation for the safety treatment of drainage devices, were analyzed to identify the studies which gave rise to the traditionally recommended criteria (trying to emphasize the important points that explain the application of such criteria). In addition to traditional recommendations, the comprehensive models were also analyzed, which deals more explicitly with the encroachments and the presence of lateral safety devices as the product of conditional probabilities that involve the encroachment probability, the probability of the encroachment occurring in a hazard envelope, the probability that the vehicle will encroach laterally far enough to reach the hazard, the probability of injury to the driver and passengers, and the cost associated with this injury. Then, the field work analyzed the practice on the use of lateral protective devices in a highway of the State of São Paulo, examining the observance to recommended criteria for using lateral protective devices and analyzing the relationship between the recommendations for the use of lateral protective devices and accident history. The results have shown that there is a deficit in the deployment on sites where the devices were recommended by traditional criteria and improved criteria. This traditional and improved criteria was also compared based on sensitivity and specificity concept, but no valuable conclusions was obtained with the use of accident data available.

The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of the state roadway network through network screening and decision making tools. In an effort to aid UDOT in meeting this goal, the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for highway safety, specifically the Utah Crash Prediction Model (UCPM) and the Utah Crash Severity Model (UCSM). Additional tools and methodologies, such as the "Hot Spot Identification and Analysis," have been created to summarize the roadway characteristics, crash data, and possible countermeasures of roadway segments with safety problems.This research focuses on the creation of a three part "Roadway Safety Analysis" methodology, which applies and automates the cumulative work of recently completed highway safety research conducted for UDOT. The first part is to prepare the roadway data and crash data for the statistical analysis. The second part is to perform the network screening statistical analysis; rank the segments by state, UDOT Region, and county; and select segments of interest. The third part is to compile and publish the Roadway Safety Analysis reports for the selected segments of interest. These parts are accomplished using the automation tools and graphical user interfaces (GUIs), which are documented in three respective volumes of user manuals. The automation tools and GUIs were developed with checks and processes to allow the Roadway Safety Analysis methodology to be completed with new, updated roadway and crash datasets.The Roadway Safety Analysis methodology allows future iterations of the UCPM and UCSM analysis and compilation of the Roadway Safety Analysis reports to be conducted in a user friendly environment. A series of critical data columns were identified to communicate the need for data consistency for future iterations of this safety research. An example of the entire process of the Roadway Safety Analysis methodology is given to illustrate how the three parts tie together. The overall process has automated data processing tasks, which saves time and resources for the analyst to investigate possible safety measures for segments of interest. Recommendations for future highway safety research are given, including continued development of the Roadway Safety Analysis methodology, an analysis of intersections and horizontal curves, the implementation of the Roadway Safety Analysis methodology to other states, and the advancement of safety countermeasures and geospatial tools for highway safety research.

Road crashes are one of the main causes of death in the United States. To reduce the number of accidents, roadway assessment programs take a proactive approach, collecting data and identifying high-risk roads before crashes occur. However, the cost of data acquisition and manual annotation has restricted the effect of these programs. In this thesis, we propose methods to automate the task of roadway safety assessment using deep learning. Specifically, we trained convolutional neural networks on publicly available roadway images to predict safety-related metrics: the star rating score and free-flow speed. Inference speeds for our methods are mere milliseconds, enabling large-scale roadway study at a fraction of the cost of manual approaches.

Distracted driving is a dangerous activity that continues to claim lives on roadways throughout the United States. A goal of this research was to collect distracted driving behavior data through observation in the field. A methodological approach was devised to keep data collection consistent across the observation periods. Analysis of the data provided information regarding trends in distraction type or driving behavior while engaging in a secondary activity. In combination with the observational portion of this research, another key component to understanding distracted driving was the crash report narrative key word search. By searching through the crash reports, it was determined which key words have high discriminating powers that indicate distraction was a key component to a crash. Additionally, the key word search demonstrated how accurately distraction related crashes are reported via the crash report form. This research contributed to the existing literature regarding distracted driving and also expanded the methods of research that are currently in use.

This study compared two LED luminaires and their abilities to provide detection distance and color recognition distance of potential roadway hazard. Detection distance is regarded as a metric of visibility. Color recognition distance is a metric for comparing the impact of the (Correlated Color Temperature) CCT of each luminaire and their color contrast impact. Mesopic vision, the mode of vision most commonly used for night driving, was considered in this study. Off-axis objects were presented to participants to assess the peripheral abilities of the luminaires. The impacts of luminance and color contrast were addressed in this study. The experiment was performed on the Virginia Smart Road where standard objects of different colors and pedestrians wearing different colors were detected by drivers of a moving vehicle in a controlled environment. The key difference between the two luminaires was their color temperatures (3500K versus 6000K). The results indicated that neither light source provided a significant benefit over the other although significant interactions were found among object color, age, and lighting level. The results indicate that the luminaires provide similar luminance contrast but their color contrasts depend heavily on the color temperature, the object, and the observer. This study followed the protocol developed by the Mesopic Optimisation of Visual Efficiency (MOVE) consortium developed by the CIE for modeling mesopic visual behavior. / Master of Science

Error related negativity (ERN) is a pronounced negative evoked response potential (ERP) that follows a known error. This neural pattern has the potential to communicate user awareness of incorrect actions within milliseconds. While the implications for human-machine interface and augmented cognition are exciting, the ERN has historically been evoked only in the laboratory using complex equipment while presenting simple visual stimuli such as letters and symbols. To effectively harness the applied potential of the ERN, detection must be accomplished in complex environments using simple, preferably single-electrode, EEG systems feasible for integration into field and workplace-ready equipment. The present project attempted to use static photographs to evoke and successfully detect the ERN in a complex visual search task: motorcycle conspicuity. Drivers regularly fail to see motorcycles, with tragic results. To reproduce the issue in the lab, static pictures of traffic were presented, either including or not including motorcycles. A standard flanker letter task replicated from a classic ERN study (Gehring et al., 1993) was run alongside, with both studies requiring a binary response. Results showed that the ERN could be clearly detected in both tasks, even when limiting data to a single electrode in the absence of artifact correction. These results support the feasibility of applied ERN detection in complex visual search in static images. Implications and opportunities will be discussed, limitations of the study explained, and future directions explored.