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A Computer Graphics Analysis of a Freeway Merge Control SystemRisher, Thomas Alan 01 January 1976 (has links) (PDF)
In 1975, C.S. Bauer completed a doctoral dissertation at the University of Florida which treated the Green Band Merging Control System on I-75 in Tampa, Florida. In this work, Bauer suggested the possibility for the use of computer graphics as a toll for analysis of the bands generated by the Green Band Control System Simulation developed in his dissertation. The use of computer generated movies of the bands displayed to ramp drivers by the system allows the comparison of various band control strategies without the need for field implementation and testing. With the goal of producing such films in mind, the research topic discussed in this paper was undertaken. The report introduces the reader to some of the basic aspects of computer graphics and presents specialized computer software and interface hardware for producing automated computer graphics movies from a Tektronix 4010 storage display. A brief discussion of the Tampa System and its associated simulation program is presented, and representative frames from the moves of the Tampa System produced in the research are discussed. Suggestions for additional work that could be undertaken in the research area conclude the report.
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Active Learning in Transportation Engineering EducationWeir, Jennifer Anne 21 December 2004 (has links)
"The objectives of this research were (1) to develop experimental active-based-learning curricula for undergraduate courses in transportation engineering and (2) to assess the effectiveness of an active-learning-based traffic engineering curriculum through an educational experiment. The researcher developed a new highway design course as a pilot study to test selected active-learning techniques before employing them in the traffic engineering curriculum. Active-learning techniques, including multiple-choice questions, short problems completed by individual students or small groups, and group discussions, were used as active interludes within lectures. The researcher also collected and analyzed student performance and attitude data from control and experimental classes to evaluate the relative effectiveness of the traditional lecture (control) approach and the active-learning (experimental) approach. The results indicate that the active-learning approach adopted for the experimental class did have a positive impact on student performance as measured by exam scores. The students in the experimental class also indicated slightly more positive attitudes at the end of the course than the control class, although the difference was not significant. The author recommends that active interludes similar to those in the experimental curricula be used in other courses in civil engineering."
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DiffServ/MPLS Network Design and ManagementAnjali, Tricha 09 April 2004 (has links)
The MultiProtocol Label Switching (MPLS) framework is used in many networks to provide efficient load balancing which distributes the traffic for efficient Quality of Service (QoS) provisioning in the network. If the MPLS framework is combined with Differentiated Services (DiffServ) architecture, together they can provide aggregate-based service differentiation and QoS. The combined use of DiffServ and MPLS in a network is called DiffServ-aware Traffic Engineering (DS-TE). Such DiffServ-based MPLS networks demand development of efficient methods for QoS provisioning. In this thesis, an automated manager for management of these DiffServ-based MPLS networks is proposed. This manager, called Traffic Engineering Automated Manager (TEAM), is a centralized authority for adaptively managing a DiffServ/MPLS domain and it is responsible for dynamic bandwidth and route management. TEAM is designed to provide a novel and unique architecture capable of managing large scale MPLS/DiffServ domains without any human interference. TEAM constantly monitors the network state and reconfigures the network for efficient handling of network events. Under the umbrella of TEAM, new schemes for Label Switched Path (LSP) setup/teardown, traffic routing, and network measurement are proposed and evaluated through simulations. Also, extensions to include Generalized MPLS (GMPLS) networks and inter-domain management are proposed.
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MPLS-Based Best-Effort Traffic EngineeringRojanarowan, Jerapong 26 September 2005 (has links)
MPLS-Based Best-Effort Traffic Engineering
Jerapong Rojanarowan
120 Pages
Directed by Dr. Henry L. Owen
The objective of this research is to develop a multipath traffic engineering framework for best-effort traffic in Multiprotocol Label Switching (MPLS) networks so as to deliver more equal shares of bandwidth to best-effort users as compared to the traditional shortest-path algorithm. The proposed framework is static and the input to the traffic engineering algorithm is restricted to network topology. Performance evaluation of this framework is conducted by simulation using ns-2 network simulator. In a multi-service capable network, some portion of the bandwidth is reserved for guaranteed services and the leftover portion is dedicated to best-effort service. This research examines the problem of traffic engineering for the remaining network bandwidth that is utilized by best-effort traffic where demands are not known a priori. This framework will result in making the limited available best-effort traffic bandwidth more equitably shared by the best-effort flows over a wide range of demands. Traditional traffic engineering research has not examined best-effort traffic.
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A profile of HOV lane vehicle characteristics on I-85 prior to HOV-to-HOT conversionSmith, Katie S. 16 November 2011 (has links)
The conversion of high-occupancy vehicle (HOV) lanes to high-occupancy toll (HOT) lanes is currently being implemented in metro Atlanta on a demonstration basis and is under consideration for more widespread adoption throughout the metro region. Further conversion of HOV lanes to HOT lanes is a major policy decision that depends on knowledge of the likely impacts, including the equity of the new HOT lane. Rather than estimating these impacts using modeling or surveys, this study collects revealed preference data in the form of observed vehicle license plate data and vehicle occupancy data from users of the HOV corridor. Building on a methodology created in Spring 2011, researchers created a new methodology for matching license plate data to vehicle occupancy data that required extensive post-processing of the data. The new methodology also presented an opportunity to take an in-depth look at errors in both occupancy and license plate data (in terms of data collection efforts, processing, and the vehicle registration database).
Characteristics of individual vehicles were determined from vehicle registration records associated with the license plate data collected during AM and PM peak periods immediately prior to the HOV lanes conversion to HOT lanes. More than 70,000 individual vehicle license plates were collected for analysis, and over 3,500 records are matched to occupancy values. Analysis of these data have shown that government and commercial vehicle were more prevalent in the HOV lane, while hybrid and alternative fuel vehicles were much less common in either lane than expected. Vehicle occupancy data from the first four quarters of data collection were used to create the distribution of occupancy on the HOV and general purpose lane, and then the matched occupancy and license plate data were examined. A sensitivity analysis of the occupancy data established that the current use of uncertain occupancy values is acceptable and that bus and vanpool occupancy should be considered when determining the average occupancy of all vehicles on the HOV lane. Using a bootstrap analysis, vehicle values were compared to vehicle occupancy values and the results found that there is no correlation between vehicle value and vehicle occupancy. A conclusions section suggests possible impacts of the findings on policy decisions as Georgia considers expanding the HOT network. Further research using these data, and additional data that will be collected after the HOT lane opens, will include emissions modeling and a study of changes in vehicle characteristics associated with the HOT lane conversion.
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Intersection discharge performanceSavage, Alpha Badamasie January 1980 (has links)
No description available.
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A profile of changes in vehicle characteristics following the I-85 HOV-to-HOT conversionDuarte, David 15 April 2013 (has links)
A 15.5-mile portion of the I-85 high-occupancy vehicle (HOV) lane in the metropolitan area of Atlanta, GA was converted to a high-occupancy toll (HOT) lane as part of a federal demonstration project designed to provide a reliable travel option through this congested corridor. Results from the I-85 demonstration project provided insight into the results that may follow the Georgia Department of Transportation's planned implementation of a $16 billion HOT lane network along metropolitan Atlanta's other major roadways [2]. To evaluate the impacts of the conversion, it was necessary to measure changes in corridor travel speed, reliability, vehicle throughput, passenger throughput, lane weaving, and user demographics. To measure such performance, a monitoring project, led by the Georgia Institute of Technology collected various forms of data through on-site field deployments, GDOT video, and cooperation from the State Road and Toll Authority (SRTA). Changes in the HOT lane's speed, reliability or other performance measure can affect the demographic and vehicle characteristics of those who utilize the corridor. The purpose of this particular study was to analyze the changes to the vehicle characteristics by comparing vehicle occupancy, vehicle classifications, and vehicle registration data to their counterparts from before the HOV-to-HOT conversion.
As part of the monitoring project, the Georgia Tech research team organized a two-year deployment effort to collect data along the corridor during morning and afternoon peak hours. One year of data collection occurred before the conversion date to establish a control and a basis from which to compare any changes. The second year of data collection occurred after the conversion to track those changes and observe the progress of the lane's performance. While on-site, researchers collected data elements including visually-observed vehicle occupancy, license plate numbers, and vehicle classification [25]. The research team obtained vehicle records by submitting the license plate tag entries to a registration database [26]. In previous work, vehicle occupancy data were collected independently of license plate records used to establish the commuter shed. For the analyses reported in this thesis, license plate data and occupancy data were collected concurrently, providing a link between occupancy records of specific vehicles and relevant demographic characteristics based upon census data. The vehicle records also provided characteristics of the users' vehicles (light-duty vehicle vs. sport utility vehicle, model year, etc.) that the researchers aggregated to identify general trends in fleet characteristics.
The analysis reported in this thesis focuses on identifying changes in vehicle characteristics that resulted from the HOV-to-HOT conversion. The data collected from post-conversion are compared to pre-conversion data, revealing changes in vehicle characteristics and occupancy distributions that most likely resulted from the implementation of the HOT lane. Plausible reasons affecting the vehicle characteristics alterations will be identified and further demographic research will enhance the data currently available to better pinpoint the cause and effect relationship between implementation and the current status of the I-85 corridor.
Preliminary data collection outliers were identified by using vehicle occupancy data. However, future analysis will reveal the degree of their impact on the project as a whole. Matched occupancy and license plate data revealed vehicle characteristics for HOT lane users as well as indications that the tested data collectors are predominantly synchronized when concurrently collecting data, resulting in an argument to uphold the validity of the data collection methods.
Chapter two provides reasons for why HOT lanes were sought out to replace I-85's HOV lanes. Chapter two will also provide many details regarding how the HOT lanes function and it will describe the role the Georgia Institute of Technology played in the assessment the HOV-to-HOT conversion. Chapter three includes the methodologies used to complete this document while chapter four provides results and analysis for the one year period before the conversion and the one year period after the conversion.
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Schedule delay of work trips in Hong Kong: anempirical analysisLi, Lok-man, Jennifer., 李諾文. January 2008 (has links)
published_or_final_version / Economics and Finance / Master / Master of Philosophy
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Comparative analysis between the diverging diamond interchange and partial cloverleaf interchange using microsimulation modelingUnknown Date (has links)
In the last decades, population growth has been outpacing transportation infrastructure growth, and today's transportation professionals are challenged to meet the mobility needs of an increasing population. The effectiveness of the transportation system is an essential constituent of people's daily lives as they commute between different points of interest. Studies show that at many highway junctions, congestion continues to worsen, and drivers are experiencing greater delays and higher risk exposures. Engineers have very little resources to handle this increase in population. One solution to resolve and alleviate congestion due to increasing traffic volumes and travel demands relies in implementing alternative designs. This approach will help traffic engineers determine which design will be the most appropriate for a particular location. This study compares and evaluates the Diverging Diamond Interchange (DDI), which is an unconventional design, to Partial Cloverleaf (ParClo) types A4 and B4 interchange designs by evaluating different Measure of Effectiveness (MOEs). Using microsimulation platform AIMSUN, each interchange type was evaluated for low, medium and high traffic flows. The analysis revealed that the DDI with four through lanes performed better than the ParClo A4 for unbalanced conditions, the DDI with six though lanes had similar results as the ParClo B4 for very high volumes. In terms of queue, the DDI design had a much better performance. The results from the analysis help in providing guidelines to the decision makers for selecting the best alternative in terms of performance. / by Borja Galletebeitia. / Thesis (M.S.C.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
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Extension and Generalization of Newell's Simplified Theory of Kinematic WavesNi, Daiheng 19 November 2004 (has links)
Flow of traffic on freeways and limited access highways can be represented as a series of kinemetic waves. Solutions to these systems of equations become problematic under congested traffic flow conditions, and under complicated (real-world) networks. A simplified theory of kinematics waves was previously proposed. Simplifying elements includes translation of the problem to moving coordinate system, adoption of bi-linear speed-density relationships, and adoption of restrictive constraints at the on- and off-ramps. However, these simplifying assumptions preclude application of this technique to most practical situations.
This research explores the limitations of the simplified theory of kinematic waves. First this research documents a relaxation of several key constraints. In the original theory, priority was given to on-ramp merging vehicles so that they can bypass any queue at the merge. This research proposes to relax this constraint using a capacity-based weighted fair queuing (CBWFQ) merge model. In the original theory, downstream queue affects upstream traffic as a whole and exiting traffic can always be able to leave as long as it gets to the diverge. This research proposes that this diverge constraint be replaced with a contribution-based weighted splitting (CBWS) diverge model. This research proposes a revised notation system, permitting the solution techniques to be extended to freeway networks with multiple freeways and their ramps. This research proposes a generalization to permit application of the revised theory to general transportation networks. A generalized CBWFQ merge model and a generalized CBWS diverge model are formulated to deal with merging and diverging traffic. Finally, this research presents computational procedure for solving the new system of equations.
Comparisons of model predictions with field observations are conducted on GA 400 in Atlanta. Investigations into the performance of the proposed CBWFQ and CBWS models are conducted. Results are quite encouraging, quantitative measures suggest satisfactory accuracy with narrow confidence interval.
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