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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.
1

Assessing the Performance of an Emergency Vehicle Preemption System: A Case Study on U.S. 1 in Fairfax County, Virginia

Mittal, Manoj Sanwarmal 16 January 2003 (has links)
Highway traffic control systems have been deployed to provide emergency vehicle preemption (EVP) at signalized intersections. Industry and transportation researchers have worked to develop analytical methods to establish the degree of benefit of emergency vehicle preemption to the emergency vehicle (EV) community and the impact on other road user groups. This thesis report illustrates the use of an analytical method to evaluate the potential impacts of EVP related to EV safety, and the potential delay to EVs and vehicles on the side street. The method uses EV-specific conflict point and delay analysis with video and other data collected in a field study conducted in Northern Virginia at the intersection of Southgate Drive and U.S. 1. EV related conflict points are characterized in terms of the EV/auto interaction geometry, the signal display, and the severity of potential crashes. EV related delay is characterized in terms of the EV/auto interaction geometry, the signal display, the level of service and the amount of delay to the EV. The EV/auto interaction, the queue length and the signal display characterize increase in delay to vehicles on the side street. The analysis indicates that the severity of EV-specific conflict points is significantly reduced with EVP. The delay to EV does not change significantly and the delay to the vehicles on the side street auto traffic increases. / Master of Science
2

Analysis of the characteristics of emergency vehicle operations in the Washington D.C. Region

Gkritza, Konstantina 27 August 2003 (has links)
Concerns about increased emergency vehicle response times in the Washington D.C. Region, especially during peak periods, have led to the implementation of signal preemption systems to facilitate the efficient and safe movement of emergency vehicles. However, to date only limited research has been carried out on the travel characteristics of emergency vehicles. This paper presents an analysis of emergency vehicle characteristics to enhance our understanding of emergency vehicle operations and impacts and to assist public agencies and other stakeholders in the planning and deployment of emergency vehicle preemption systems. Emergency vehicle characteristics that merit special attention include temporal and spatial distribution of emergency vehicle travel; frequency and duration of preemption requests; platoon responses; and crashes involving emergency vehicles. Data on major corridors in Fairfax County, Virginia and Montgomery County, Maryland are used in the analysis. The analysis indicates that such data are useful to assess the need for a preemption system along major arterials. Moreover, the analysis demonstrates the importance of considering emergency vehicle preemption impacts regarding delay to other vehicles. It is also important to note that there is some variability in the emergency vehicle characteristics depending on the proximity of a firehouse to an intersection and other factors. It is proposed that future efforts build upon this research to develop warrants to be used in determining the appropriateness of installing preemption systems at signalized intersections. / Master of Science
3

Bus lanes with intermittent priority assessment and design /

Eichler, Michael David. January 2005 (has links) (PDF)
Thesis (M.A. in City and Regional Planning)--University of California, Berkeley, Fall 2005. / Title from PDF title page (viewed Dec. 13, 2007). "Fall 2005." Includes bibliographical references (p. 81-87).
4

Evaluation of transit signal priority effectiveness using automatic vehicle location data

Sundstrom, Carl Andrew. January 2008 (has links)
Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Member: Garrow, Laurie; Committee Member: Hunter, Michael; Committee Member: Meyer, Michael.
5

Impacts of queue jumpers and transit signal priority on bus rapid transit

Unknown Date (has links)
Exclusive bus lanes and the Transit Signal Priority are often not effective in saturated peak-traffic conditions. An alternative way of providing priority for transit can be queue jumpers, which allows buses to bypass and then cut out in front of waiting queue by getting an early green signal. Utah Transit authority deployed Bus Rapid Transit system at Salt Lake County, Utah along W 3500 S. This research evaluates the impacts of queue jumpers with TSP on Bus Rapid Transit (BRT) and private vehicular traffic. Four VISSIM models were developed for analysis : Basic scenario, no TSP with queue jumpers, TSP with no queue jumbers, and TSP with queue jumpers. In TQ scenario travel time was reduced between 13.2-19.82% with respect to basic scenario. At the same time, travel time of private traffic increased very little 0.38-3.28%. Two TSP strategies : green extension and red truncation are implemented in this research work. / by R.M. Zahid Reza. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
6

A microsimulation analysis of highway intersections near highway-railroad grade crossings

Tydlacka, Jonathan Michael 15 November 2004 (has links)
The purpose of this thesis was to perform microsimulation analyses on intersections near Highway-Railroad Grade Crossings (HRGCs) to determine if controlling mean train speed and train speed variability would improve safety and reduce delays. This research focused on three specific areas. First, average vehicle delay was examined, and this delay was compared for seven specific train speed distributions, including existing conditions. Furthermore, each distribution was associated with train detectors that were placed at the distance the fastest train could travel during the given warning time. Second, pedestrian cutoffs were investigated. These cutoffs represented an occasion when the pedestrian phases were truncated or shortened due to railroad signal preemption. Finally, vehicle emissions were analyzed using a modal emissions model. A microscopic simulation model of the Wellborn Corridor in College Station, Texas was created using VISSIM. The model was run twenty times in each train speed distribution for each of three train lengths. Average vehicle delay was collected for three intersections, and delays were compared using the Pooled t-test with a 95% confidence interval. Comparisons were made between the distributions, and generally, distributions with higher mean train speeds were associated with lower average delay, and train length was not a significant factor. Unfortunately, pedestrian cutoffs were not specifically controlled in this project; therefore, no statistical conclusions can be made with respect to the pedestrian cutoff problem. However, example cases were devised to demonstrate how these cutoffs could be avoided. In addition, vehicle emissions were examined using the vehicle data from VISSIM as inputs for CMEM (Comprehensive Modal Emissions Model). For individual vehicles, as power (defined as the product of velocity and acceleration) increased, emissions increased. When comparing emissions from different train speed distributions, few significant differences were found. However, a scenario with no train was tested, and it was shown to have significantly higher emissions than three of the distributions with trains. Ultimately, this thesis shows that average vehicle delay and vehicle emissions could be lowered by specific train speed distributions. Also, work could be done to investigate the pedestrian cutoff problem.
7

A microsimulation analysis of highway intersections near highway-railroad grade crossings

Tydlacka, Jonathan Michael 15 November 2004 (has links)
The purpose of this thesis was to perform microsimulation analyses on intersections near Highway-Railroad Grade Crossings (HRGCs) to determine if controlling mean train speed and train speed variability would improve safety and reduce delays. This research focused on three specific areas. First, average vehicle delay was examined, and this delay was compared for seven specific train speed distributions, including existing conditions. Furthermore, each distribution was associated with train detectors that were placed at the distance the fastest train could travel during the given warning time. Second, pedestrian cutoffs were investigated. These cutoffs represented an occasion when the pedestrian phases were truncated or shortened due to railroad signal preemption. Finally, vehicle emissions were analyzed using a modal emissions model. A microscopic simulation model of the Wellborn Corridor in College Station, Texas was created using VISSIM. The model was run twenty times in each train speed distribution for each of three train lengths. Average vehicle delay was collected for three intersections, and delays were compared using the Pooled t-test with a 95% confidence interval. Comparisons were made between the distributions, and generally, distributions with higher mean train speeds were associated with lower average delay, and train length was not a significant factor. Unfortunately, pedestrian cutoffs were not specifically controlled in this project; therefore, no statistical conclusions can be made with respect to the pedestrian cutoff problem. However, example cases were devised to demonstrate how these cutoffs could be avoided. In addition, vehicle emissions were examined using the vehicle data from VISSIM as inputs for CMEM (Comprehensive Modal Emissions Model). For individual vehicles, as power (defined as the product of velocity and acceleration) increased, emissions increased. When comparing emissions from different train speed distributions, few significant differences were found. However, a scenario with no train was tested, and it was shown to have significantly higher emissions than three of the distributions with trains. Ultimately, this thesis shows that average vehicle delay and vehicle emissions could be lowered by specific train speed distributions. Also, work could be done to investigate the pedestrian cutoff problem.
8

Development of dynamic real-time integration of transit signal priority in coordinated traffic signal control system using genetic algorithms and artificial neural networks

Ghanim, Mohammad Shareef. January 2008 (has links)
Thesis (Ph. D.)--Michigan State University. Dept. of Civil Engineering, 2008. / Title from PDF t.p. (viewed on July 7, 2009) Includes bibliographical references (p. 196-201). Also issued in print.
9

Designing an Emergency Traffic Signal System (ETSS): A Case Study of an Intersection Along U.S.1, Fairfax County, Virginia

Mohammed, Taqhiuddin 10 July 2003 (has links)
Access to highways from a local firehouse is a major problem for emergency services. Motorists often do not see flashing lights or hear sirens from the approaching emergency vehicles (EV) until emergency vehicles reach the highway entrance, often too late to take appropriate action. Many locations have installed special signals called emergency traffic signal systems (ETSS) or used signal preemption to notify motorists and to stop traffic to allow the emergency vehicle to enter the highway safely. This thesis will examine the effectiveness of one such installation at the intersection along U.S.1 at Beedo Street and some of the impacts it has on highway traffic. The evaluation of the said installation is carried out in terms of delay to EV; conflict potential between EV and other vehicles and response of the motorists to the ETSS. This thesis also proposes two alternative designs of ETSS to improve the existing signal system. / Master of Science
10

A Macroscopic Model for Evaluating the Impact of Emergency Vehicle Signla Preemption on Traffic

Casturi, Ramakrishna 11 May 2000 (has links)
In the past, the study of Emergency Vehicle (EV) signal preemption has been mostly done using field studies. None of the simulation models that are currently commercially available have the capability to model the presence of EVs and simulate the traffic dynamics of the vehicles surrounding them. This study presents a macroscopic traffic model for examining the effect of signal preemption for EVs on traffic control measures, roadway capacity, and delays incurred to the vehicles on the side streets. The model is based on the cell transmission model, which is consistent with the hydrodynamic theory of traffic flow. A special component, in the form of a moving bottleneck that handles the traffic dynamics associated with the presence of EVs, was developed in the model. Several test scenarios were constructed to demonstrate the capabilities of the model for studying the impact of signal preemption on an arterial with multiple intersections under various traffic demand levels and varying frequencies of the arrival of EVs. Performance measures, such as average vehicle delay, maximum delay, and standard deviation of delay to traffic on all approaches, were obtained. An additional advantage of the model, apart from the capability to model EVs, is that the state-space equations used in the model can be easily incorporated into a mathematical programming problem. By coupling with a desired objective function, the model can be solved analytically. Optimal solutions can be generated to obtain insights into the development of traffic control strategies in the presence of EVs. / Master of Science

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