A. James Clark School of Engineering
Permanent URI for this communityhttp://hdl.handle.net/1903/1654
The collections in this community comprise faculty research works, as well as graduate theses and dissertations.
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Item Development of Planning And Evaluation Models For Superstreets(2016) Xu, Liu; Chang, Gang-Len; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Despite the extensive implementation of Superstreets on congested arterials, reliable methodologies for such designs remain unavailable. The purpose of this research is to fill the information gap by offering reliable tools to assist traffic professionals in the design of Superstreets with and without signal control. The entire tool developed in this thesis consists of three models. The first model is used to determine the minimum U-turn offset length for an Un-signalized Superstreet, given the arterial headway distribution of the traffic flows and the distribution of critical gaps among drivers. The second model is designed to estimate the queue size and its variation on each critical link in a signalized Superstreet, based on the given signal plan and the range of observed volumes. Recognizing that the operational performance of a Superstreet cannot be achieved without an effective signal plan, the third model is developed to produce a signal optimization method that can generate progression offsets for heavy arterial flows moving into and out of such an intersection design.Item PERFORMANCE AND QUALITY INDICATOR DATA AVAILABILITY FOR P3 PROJECTS(2015) Robinson, Matthew Christian; Cui, Qingbin; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Public Private Partnerships (P3’s) are a relatively new project delivery method. In reaction to the increased attention to this delivery method, the Federal Highway Administration has begun to enhance its existing P3-VALUE toolkit, an educational toolkit which demonstrates the potential benefits of utilizing a Public Private Partnership over a traditional method like Design Bid Build for transportation projects. The toolkit utilizes assumptions about P3 project characteristics to build the scenarios for its analyses. Unfortunately, there is a significant lack of data which would serve to justify assumptions made about improved P3 quality performances. Furthermore, there is a basic lack of knowledge regarding what data is even available to make certain assumptions. The intent of this thesis is to identify what data can be collected, what data can be shared, and to determine what data can be expected to be reliably available, and not subject to proprietary rights, for future analysis regarding the improved P3 quality performance.Item Evaluation-Focused Reliability Test Program Planning Methodology(2013) Tamburello, Robert Nicholas; Herrmann, Jeffrey W; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In practice, various ad hoc approaches for designing reliability test programs have been observed. Many of these approaches rely on previously established rules of thumb for which the underlying rationale is indefensible. As a consequence, those who use such approaches are unlikely to maintain a firm resource commitment for the conduct of reliability test program activities. Furthermore, it is difficult to ascertain the impact that budgetary cuts will have on the adequacy of the reliability test program with any degree of accuracy. The contributions of this research are as follows. This dissertation presents a novel 7-step planning process to aid practitioners in designing adequate reliability test programs. This planning process serves as a tool to systematically identify, quantify, and mitigate evaluation risks subject to resource constraints. By performing the 7 steps associated with this planning process, practitioners will be able to logically justify reliability test program requirements and more effectively articulate the significance of evaluation risks associated with a particular reliability test program design. Additionally, it is a straightforward process to assess the impact of a reduction in reliability test program resources. This planning process includes a step for assessing the level of risk associated with key aspects of the reliability test program. One such consideration that is of paramount importance is the adequacy of the test configuration of the system. Hence, we present a simulation-based approach for assessing the adequacy of the test configuration of a complex system-of-systems. For the purpose of demonstration, an application of this approach to air defense systems is included; however, the approach is valid for any type of system. As well, this dissertation presents an evaluation risk assessment process for reliability test programs--adapted from the traditional failure mode and effects analysis (FMEA) process. This process can be applied to any reliability test program, irrespective of the manner in which the plan was formulated. Just as a FMEA facilitates the identification of potential weaknesses in a system architecture, this evaluation risk assessment process is designed to surface reliability test program weaknesses and gauge the potential impact of each weakness to the system reliability evaluation.Item EMPIRICAL ANALYSIS OF THE QUALITY, EFFECTIVNESS, AND LOCALIZED IMPACTS OF HIGHWAY DYNAMIC MESSAGE SIGN MESSAGES(2011) Fish, Robin Lee Wilson; Haghani, Ali; Civil Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The need to convey accurate, real-time travel information to road users has long been recognized by transportation engineers. One of the primary means to accomplish this is the operation of highway Dynamic Message Signs (DMS). Though utilized for over 50 years, the quality of messages used, their effectiveness in influencing traffic, and the localized impacts they have are not well documented. This thesis introduces Bluetooth traffic detection sensors as a new tool for evaluation of DMS message quality and resulting route choice decisions. In addition, highway speed sensors are used to determine whether DMS influence changes in local traffic speeds. The findings indicate DMS messages are generally accurate in communicating prevailing conditions and can influence the route choice behavior of drivers. The speed analysis indicated that certain messages have more influence on traffic than others, though the majority of messages do not negatively affect traffic speeds.