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The present study investigated the extent to which importance ratings (i.e., a measure of perceived importance for driving-related concepts) are a viable alternative to traditional mental model assessment methods in predicting driving performance. Although mental models may predict driving–related outcomes—crash involvement and moving violations—common mental model assessment techniques are associated with administrative limitations and challenges, which can affect how valid mental models are as assessments of knowledge structure. Importance ratings, as a measure of driving-related knowledge that may be associated with fewer administrative limitations, were hypothesized to provide equal predictive validity for driving–related performance outcomes in a sample of undergraduate students. To investigate the extent to which the measurement of mental models and importance ratings contribute to the prediction of driving crashes and moving violations, students completed Pathfinder, a common computer-based mental model assessment method, and paper-and-pencil importance ratings. In addition, students completed a test of driving knowledge and reported driving behaviors and outcomes including at-fault crashes and moving violations that occurred over the past five years (i.e., from 2005 to 2009). A group of expert drivers completed mental model and importance ratings assessments as well. Data across expert raters were combined and analyzed for appropriateness to serve as referent scores for each assessment. Students' mental model accuracy as well as importance rating accuracy was based on the extent to which student mental models and ratings agreed with those provided by the group of expert drivers. The results suggest that importance rating and mental model accuracy predicted crash involvement and moving violations. Whereas mental model accuracy was a stronger predictor of the number of moving violations, importance rating accuracy predicted the number of at-fault crashes slightly better than mental models. Although inconclusive, these results suggest that importance ratings may be a viable alternative to traditional mental model assessment in predicting some driving outcomes. Future research is warranted on importance ratings and other alternative mental model assessments.

During administer mobil source examine and control plan , we must estimate emission amount , curtail amount and curtail rate , to estimate the improve effection . But there has very few data of this aspect , especially real road driving pattern to calcul ate emission factory and amount . So it¡¦s necessary to proceed this aspect investigate. The investigate have two parts include driving pattern and emission factor . Determine item is CO , THC and NOx .The result of driving Ping-tung area have faster speed,longer navigate time and larger acceleration and deceleration . The result of emission factor¡GCO is 6.79 (¡Ó3.39) g/km , THC is 1.63 (¡Ó1.27) g/km and NOx is 0.13(¡Ó0.14) g/km . Idle emission CO is 1.03%(¡Ó1.19%)¡ATHC is 1400(¡Ó2138) ppm

Due to the changing society in Taiwan, R.O.C., values are badly twisted. Many teenagers make use of holiday nights to gather on highways to conduct dangerous driving (motorcycle racing). They cause traffic jams and obstruct traffic notoriously. What's worse, they even use violence to attack passengers, on-duty policemen and related government offices. Such behaviors not only break the law but also critically endanger social public security, posing threat to people's lives, bodies and properties. As police plays a role of maintaining social public security, the crackdowns and control of dangerous driving behaviors are important duties exercised by police. Dangerous driving control projects mainly adopt a "top-down" policy implementation model. The model emphasizes policy makers' decisions on policy goals and their leading position in directing actions. Basically, policy implementers are required to execute policy makers' will, that is, carry out supervisors' intentions and goals loyally in a strictly obedient top-down bureaucratic system. The model on one hand emphasizes a closely linked chain of orders and supervisors' control abilities; on the other hand, it advocates policy makers' reasonable design of policy implementation structure and regulations. Besides, the adoption of top-down implementation model usually emphasizes supervisors' goal-setting and project-planning abilities and overlooks lower-level implementers' motives, intentions and values. As it underestimates local officials' abilities in influencing policy goals, would it neglect a counterproductive effect exerted by policy implementers? While emphasizing laws and regulations, does it provide implementers with any discretion? Could it become a policy implementation game? As regards the bottom-up implementation model, it addresses the need of providing lower-level officials or local implementation organizations with discretion, which enables them to make suitable policies against a complicated environment. This means proper authorization for lower-level departments and subordinates to participate in policy making and implementation. In the model, supervisors or policy makers are not policy leaders but rather supporters who leave sufficient room for discretion so lower-level officials or local implementation organizations can construct a policy implementation process adaptable to the implementation environment. In such thinking mode and from the aspect of policy implementation, the study tries to examine and evaluate police organizations' dangerous driving control policies. A case study of the police organizations in Kaohsiung City was conducted. Based on a policy implementation theory constructed from three research approaches - top-down model of the first generation, bottom-up model of the second generation and integrated model of the third generation, the study made a comprehensive survey of the three research approaches and used it as the research method of the study. The main structure of the study is divided into five chapters: Chapter One - Introduction, which describes the motive, purpose and scope of study and definition of related terms; Chapter Two - Theory Basis and Literature Review, which reviews literature associated with the policy implementation theory constructed from the three research approaches, builds a study framework and decides research methods to be used in the study; Chapter Three - Research Methods, Scope and Limitations; Chapter Four - Analysis of the Results of Evaluation of Police Organizations' Dangerous Driving Control Policies, which makes analysis and induction through in-depth interviews with police officers to find out the reasons for various behaviors that affect police officers' implementation of dangerous driving control policies; Chapter Five - Conclusion and Suggestions, which raises problems discovered in the study, proposes improvement suggestions on dangerous driving control, provides police organizations with the best implementation tool from various dangerous driving control policies and analyses which one is the best in consideration of the choice and use of police tools.

Thesis (M.A.) -- University of Texas at Arlington, 2008.

Driving under the influence of alcohol (DUIA) is well recognized as one of the key human factors that increase the risks of traffic accidents and associated injuries and fatalities. These risks increase rapidly with the alcohol concentration in human body. Unfortunately, drink-driving not only increases the accident and injury risks of drivers, but also increases the risks to innocent road users. Despite the decrease in the number of alcohol-related accidents over the past decade, few comprehensive studies have investigated the relationship between the drivers’ alcohol consumption, the actual impairment in driving performance due to alcohol, and the resulting accident and injury risks. Therefore, the development of an appropriate road safety policy framework would help to formulate appropriate measures and penalties for combating drink-driving, thus reducing the associated injuries and fatalities in the long term. To better understand the relationship between drink-driving and traffic safety, this study attempts to evaluate the alcohol-impaired effect on traffic safety in a three-pronged approach: risk analysis, physiological performance, and attitudinal evaluation. For the crash risk analysis, impairment effects of alcohol on the severity of injuries and road crashes in Hong Kong were determined using the comprehensive random breath test (RBT) data. For the physiological performance, simulation study was conducted to develop a temporal profile of driver alcohol concentration and to determine the relationship between driver alcohol concentration and the actual alcohol-impaired driving performance for Chinese populations. Finally, for the attitudinal evaluation, a perception survey was used to evaluate the effectiveness of legislation on drivers’ intention to reduce drink-driving. Findings of the three-pronged analysis were then integrated to provide a useful tool for formulating effective legislation and enforcement measures to combat drink-driving, with respect to the driver’s perceptions, observed driving performance, and actual road safety levels in the long term. / published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

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This research develops an optimization model for eco-driving at signalized intersection. In urban areas, signalized intersections are the “hot spots” of air emissions and have significant negative environmental and health impacts. Eco-driving is a strategy which aims to reduce exclusive fuel consumption and emissions by modifying or optimizing drivers’ behaviors. With the help of vehicle-to-vehicle (V2V) communication and vehicle-to-infrastructure communication (V2I), eco-driving could utilize the signal phase and the queue-discharging time information to optimize the speed trajectories for the vehicles approaching an intersection in order to reduce fuel consumption and emissions. A few research studies have been conducted on the development of algorithms that utilize traffic signal information to reduce fuel consumption and emissions. Hence, the goal of this research is to develop an optimization model to determine the optimal eco-driving trajectory (the speed profile) at a signalized intersection, which aims to achieve the minimization of a linear combination of emissions and travel time. Then enumeration method, simplex optimization and genetic algorithm are investigated to determine a practicable and efficient method to solve the proposed optimization problem. As various scenarios of distance from the vehicle to the intersection, queue discharging time and weights of emission/travel time will lead to different optimal trajectories and different emissions and travel times. A sensitivity study is conducted to analyze and compare the performance of the optimal solution in various scenarios of different such parameters. In addition, a baseline study is conducted to investigate the benefits of eco-driving when drivers only decelerate in advance but not apply the recommended speed trajectory. The results of case study show that genetic algorithm is a preferred method to solve the proposed optimization problem; Eco-driving could achieve satisfied reduction in emissions without significantly increasing travel time and emissions is more sensitive to various scenarios than travel time; Eco-driving still could achieve reduction in emissions as long as the drivers decelerate earlier even though the they would not apply the recommended speed trajectory under certain conditions.

Cooperative driving holds the potential to considerably improve the level of safety and efficiency on our roads. Recent advances in in-vehicle sensing and wireless communication technology have paved the way for the development of cooperative traffic safety applications based on the exchange of data between vehicles (or between vehicles and road side units) over a wireless link. The access to up-to-date status information from surrounding vehicles is vital to most cooperative driving applications. Other applications rely on the fast dissemination of warning messages in case a hazardous event or certain situation is detected. Both message types put high requirements on timeliness and reliability of the underlying communication protocols. The recently adopted European profile of IEEE 802.11p defines two message types,periodic beacons for basic status exchange and event-triggered hazard warnings, both operating at pre-defined send rates and sharing a common control channel. The IEEE 802.11p Medium Access Control (MAC) scheme is a random access protocol that doesnot offer deterministic real-time support, i.e. no guarantee that a packet is granted access to the channel before its deadline can be given. It has been shown that a high number of channel access requests, either due to a high number of communicating vehicles or highdata volumes produced by these vehicles, cannot be supported by the IEEE 802.11p MAC protocol, as it may result in dropped packets and unbounded delays. The goal of the work presented in this thesis has therefore been to enhance IEEE 802.11p without altering the standard such that it better supports the timing and reliability requirements of traffic safety applications and provides context-aware andefficient use of the available communication resources in a vehicular network. The proposed solutions are mapped to the specific demands of a set of cooperative driving scenarios (featuring infrastructure-based and infrastructure-free use cases, densely and sparsely trafficked roads, very high and more relaxed timing requirements) and evaluated either analytically, by computer simulation or by measurements and compared to the results produced by the unaltered IEEE 802.11p standard. As an alternative to the random MAC method of IEEE 802.11p, a centralized solution isproposed for application scenarios where either a road side unit or a suitable dedicated vehicle is present long enough to take the coordinating role. A random access phase forevent-driven data traffic is interleaved with a collision-free phase where timely channel access of periodic delay-sensitive data is scheduled. The ratio of the two phases isdynamically adapted to the current data traffic load and specific application requirements. This centralized MAC solution is mapped on two cooperative driving applications: merge assistance at highway entrances and platooning of trucks. Further,the effect of a context-aware choice of parameters like send rate or priority settings based on a vehicle’s position or role in the safety application is studied with the goal to reduce the overall number of packets in the network or, alternatively, use the available resources more efficiently. Examples include position-based priorities for the merge assistance use case, context-aware send rate adaptation of status updates in anovertaking warning application targeting sparsely-trafficked rural roads and an efficient dissemination strategy for warning messages within a platoon. It can be concluded that IEEE 802.11p as is does not provide sufficient support for the specific timing and reliability requirements imposed by the exchange of safety-criticalreal-time data for cooperative driving applications. While the proper, context-awarechoice of parameters, concerning send rate or priority level, within the limits of the standard, can lead to improved packet inter-arrival rates and reduced end-to-end delays,the added benefits from integrating MAC solutions with real-time support into the standard are obvious and needs to be investigated further.

Civil engineering construction frequently requires the use of piles to carry structural loads to stronger ground strata or to control lateral ground movements. A variety of techniques are available to install piles into the ground. Of central interest to this research is the vibratory hammer, or vibrodriver, which is the preferred method used to drive piles into granular soils. .The installation of sheet and bearing piles by vibrodriver causes periodic vibration in the adjacent ground which is severe very close to the piles, but attenuates with distance. A potential consequential effect of the vibrations that are caused by vibrodriving is ground compaction, which may be observed as differential surface settlement. It is desirable that vibration induced ground compaction settlement should be estimated for contracts where loose to medium-dense granular soils occur, especially when buildings on shallow foundations or poorly bedded service pipes are adjacent. It is unlikely that a simple in-situ soils test will allow accurate, specific estimates, but rather that a range of vibratory tests should be performed which can then be used as a knowledge base. Settlement trends and associated parameters can then be identified which will allow the prediction of settlement with reference to the in-situ soil and the ground vibration data. This argument forms the basis of the laboratory test programme. A range of granular soils were studied using an adapted 150mm Rowe cell (a hydraulic oedometer). Use of the Rowe cell enabled samples to experience compaction under effective stress conditions that are appropriate for equivalent soils in the field. The complete cell was mounted on an electromagnetic shaker and after static consolidation, the samples were vibrated under maintained hydraulic load, at frequencies and accelerations that are appropriate for soils adjacent to vibrodrivers. Change in sample height was recorded for controlled vertical (and horizontal) vibrations, typically in the range of 0.lg to 5.0g at 25Hz and 40Hz. Soils were tested under a range of effective stresses and moisture content. The results of the laboratory programme and subsequent data analysis are presented in tables and diagrams. Expressions that describe a good relationship between acceleration, soil type, relative density and static load allow upperbound estimates of vibratory settlements to be made for accelerations of up to 6.0g. An additional expression is presented that accounts for the influence of moisture content, ground vibration frequency and vibration duration. Summary tables are presented that define categories of vibration induced ground compaction settlement based on settlement potential, risk and severity. The use of the settlement equations and the influence of various parameters are demonstrated for a range of example applications, hi addition, data is abstracted from case studies found in the literature and sites that were visited during the research. The abstracted data are then used to perform settlement estimates which are compared to the reported examples. Good correlation between observed and calculated settlement is demonstrated in many cases. However, in some instances, it appears that ground settlements were exacerbated by at least one additional mechanism, such as cumulative pore water pressure increase, or lateral movement of sheet piles, in addition, extraction of piles by vibrodriver appears to contribute significantly to the reported cases of ground settlement.