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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Real-time control and optimization of traffic signal timing transition for emergency vehicle preemption /

Qin, Xiaolin, January 1900 (has links)
Thesis (Ph.D.) - Carleton University, 2006. / Includes bibliographical references (p. 329-342). Also available in electronic format on the Internet.
42

Statistical analysis of crashes occurring at intersections in malfunction flash

Watson, Christopher Earl. January 2008 (has links)
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Member: Hunter, Michael; Committee Member: Meyer, Michael; Committee Member: Rodgers, Michael. Part of the SMARTech Electronic Thesis and Dissertation Collection.
43

Observation and analysis of driver behavior at intersections in malfunction flash mode

Truong, Y-Thao. January 2008 (has links)
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Hunter, Michael; Committee Member: Meyer, Michael; Committee Member: Rodgers, Michael. Part of the SMARTech Electronic Thesis and Dissertation Collection.
44

Combined traffic signal control and traffic assignment : algorithms, implementation and numerical results /

Lee, Chungwon, January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 272-284). Available also in a digital version from Dissertation Abstracts.
45

Incident detection on arterials using neural network data fusion of simulated probe vehicle and loop detector data /

Thomas, Kim. January 2005 (has links) (PDF)
Thesis (M.Phil.) - University of Queensland, 2005. / Includes bibliography.
46

Freeway Control Via Ramp Metering: Development of a Basic Building Block for an On-Ramp, Discrete, Stochastic, Mesoscopic, Simulation Model within a Contextual Systems Approach

Alkadri, Mohamed Yaser 01 January 1991 (has links)
One of the most effective measures of congestion control on freeways has been ramp metering, where vehicle entry to the freeway is regulated by traffic signals (meters). Meters are run with calibrated influx rates to prevent highway saturation. However, recent observations of some metering sites in San Diego, CA indicate that metering, during peak hour demand, is helping freeway flow while sometimes creating considerable traffic back-ups on local streets, transferring congestion problems from the freeway to intersections. Metering problems stem largely from the difficulty of designing an integrated, dynamic metering scheme that responds not only to changing freeway conditions but also to fluctuating demand throughout the ramp network; a scheme whose objective is to maintain adequate freeway throughput as well as minimize disproportionate ramp delays and queue overspills onto surface streets. Simulation modeling is a versatile, convenient, relatively inexpensive and safe systems analysis tool for evaluating alternative strategies to achieve the above objective. The objective of this research was to establish a basic building block for a discrete system simulation model, ONRAMP, based on a stochastic, mesoscopic, queueing approach. ONRAMP is for modeling entrance ramp geometry, vehicular generation, platooning and arrivals, queueing activities, meters and metering rates. The architecture of ONRAMP's molecular unit is designed in a fashion so that it can be, with some model calibration, duplicated for a number of ramps and, if necessary, integrated into some other larger freeway network models. SLAM.II simulation language is used for computer implementation. ONRAMP has been developed and partly validated using data from eight ramps at Interstate-B in San Diego. From a systems perspective, simulation will be short-sided and problem analysis is incomplete unless the other non-technical metering problems are explored and considered. These problems include the impacts of signalizing entrance ramps on the vitality of adjacent intersections, land use and development, "fair" geographic distribution of meters and metering rates throughout the freeway corridor, public acceptance and enforcement, and the role and influence of organizations in charge of decision making in this regard. Therefore, an outline of a contextual systems approach for problem analysis is suggested. Benefits and problems of freeway control via ramp metering, both operational short-term and strategic long-term, are discussed in two dimensions: global (freeway) and local (intersection). The results of a pilot study which includes interviews with field experts and law enforcement officials and a small motorist survey are presented.
47

Audible pedestrian signals: a feasibility study

Oliver, Morris Bernard 01 August 2012 (has links)
This report represents a concentrated effort that determines the feasibility of audible pedestrian signals. These signals are devices which give auditory cues to help the visually impaired cross safely at difficult intersections. Surveys were sent out to over 100 organizations, audible signal manufacturers, and cities who have knowledge of the devices, and responses were analyzed. The devices were found to be feasible but only at certain complex and confusing intersections. Twelve criteria for the installation of the devices were developed as were twelve criteria for the operation of the devices. Buzzers, constant tones, bird calls, and voice signals were examined by obtaining information from traffic engineers who had experience with each sound. It was determined that intermittent tones were the most effective for human localization. For the most widely used devices, cost data were developed for the products, installation, and maintenance. A partial listing of the U.S. and foreign cities which have the devices was compiled along with a partial listing of audible signal manufacturers. The problems the visually impaired face as well as their suggested solutions are listed. Topics for further study include the use of hand-held devices which activate sound signals at intersections and the development of tone schemes for 4-leg and multi-leg intersections which are not north south and east-west. An additional topic for future study is the development of tone schemes for traffic circles. / Master of Science
48

Transit signal priority for emergency evacuation: mitigating disaster

Unknown Date (has links)
The goal of this research is to answer a single question. During an urban evacuation, is it advisable for regional planners to allow transit units signal priority in cases where police assisted traffic controls are not an option? Standard practice for emergency evacuation is to place police officers at intersection throughout the evacuation area. However, this is not always an option where environmental factors such as the presence of fire, chemical plume, radioactive fallout (nuclear contaminated wind and dust) do not permit police presence. Results from a case study conducted on Washington D.C. show that it would take four non-prioritized transit units to accomplish the same task as three prioritized vehicles. Furthermore, allowing transit signal priority during an urban evacuation has little to no effect on evacuation clearance time or evacuee travel time. Moreover, when transit signal priority is restricted to operate only on evacuation routes, evacuee travel and delay time decreases. / by Scott A. Parr. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
49

Adaptive fuzzy systems for traffic responsive and coordinated ramp metering /

Bogenberger, Klaus. January 1900 (has links)
Originally presented as the author's Thesis (doctoral)--Technische Universität München. / "FGV-TUM." Includes bibliographical references (p. 147-156).
50

Statistical analysis of crashes occurring at intersections in malfunction flash

Watson, Christopher Earl 19 November 2008 (has links)
This thesis presents an analysis of the characteristics of malfunction flash incidents based on the Georgia Department of Transportation crash reporting database. Malfunction flash is an unintentional state of flash mode in intersection signal hardware. The flash mode is a signal indication of yellow/red or red/red flash. The flash mode can be due to many issues, such as hardware failure, damage, or storms. Crash reports are completed by police officers at the scene. After processing by the local jurisdiction reports are sent to GDOT for archiving and analysis. GDOT archives the reports in a PDF image format without editable text. This research will develop a procedure to convert the archived PDF reports to text files using optical character recognition (OCR) software. The developed procedure will extract the description paragraph of the incident from the PDF. The extracted descriptions may then be searched for useful information about the incident. The text files will be run through a filter for keywords, such as; "malfunction flash," "red/red flash," "yellow/red flash," and others. Incidents flagged by the keywords will be reexamined to determine if they are malfunction flash incidents. The 2006 GDOT incident data base will be used for this effort. From an original possible candidate list of 70,000 signalized intersection incidents malfunction incidents will be identified using this method. A statistical analysis will be completed seeking trends and important characteristics of malfunction incidents.

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