The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform

J Jenq - One of the best experts on this subject based on the ideXlab platform.

  • traffic signal coordination across jurisdictional boundaries field evaluation of efficiency energy environmental and safety impacts
    Transportation Research Record, 2000
    Co-Authors: Hesham A Rakha, Alejandra Medina, H Sin, Francois Dion, M Van Aerde, J Jenq
    Abstract:

    Some insight into the potential benefits of coordinating traffic signals across jurisdictional boundaries by using as a case study the Scottsdale Road-Rural Road corridor in the Arizona cities of Tempe and Scottsdale is provided. In particular, the feasibility of using second-by-second speed measurements from Global Positioning System-equipped vehicles for evaluation of the environmental and safety impacts of operational-level traffic improvement projects is demonstrated. The use of statistical models for the evaluation of efficiency, energy, emissions, and safety benefits of operational-level traffic improvement projects without the need to invest in expensive equipment such as emissions analyzers is also demonstrated. Furthermore, it is also shown that the use of statistical models allows evaluation of measures of effectiveness that would not otherwise be evaluated, such as accident risk. On the basis of a field evaluation of the main travel corridor of the study area, it was determined that the signal ...

Kelly Leone - One of the best experts on this subject based on the ideXlab platform.

  • measures of effectiveness for passenger baggage security screening
    Transportation Research Record, 2003
    Co-Authors: Kelly Leone
    Abstract:

    One of the most challenging tasks of the Aviation and Transportation Security Act of 2001 is to meet the goal of performing explosive detection system (EDS) screening on 100% of checked baggage by the end of calendar year 2002. Accomplishing this goal within the imposed deadline and within the typically tight space constraints of airport terminals will require significant changes in the way airlines and airports manage passengers and their baggage. One of the up-front keys to integrating 100% checked-baggage screening into airports is to identify realistic throughput rates of various EDS machines available to Transportation Security Administration (TSA) planners. Some of the issues associated with the implementation of EDS equipment are discussed, and an analysis is performed on the throughput of the equipment, using modeling and discrete event-simulation tools. One conclusion of the analysis is that a significant difference exists between the scan rate and the effective throughput rate for the InVision C...

Edward J Fitzsimmons - One of the best experts on this subject based on the ideXlab platform.

  • portable traffic signals in conjunction with pilot car operations at two lane two way rural highway work zones
    Transportation Research Record, 2016
    Co-Authors: Steven D Schrock, Shivraj S Patil, Edward J Fitzsimmons
    Abstract:

    A portable traffic signal (PTS) system is designed to move traffic through two-way rural highway work zones with one lane open to traffic. The primary objective of this study was to evaluate the use of PTS systems in conjunction with pilot car operations and to compare three conditions as means to control traffic at one-lane, two-way work zones: (a) flagging only, (b) PTS with flagger, and (c) PTS only. The measures of effectiveness were determined with respect to (a) red light running (RLR) violation percentages, (b) vehicle delay estimates, (c) queue lengths, and (d) green interval time. Comparisons of the operational parameters of average wait time, average queue length, and average green interval length indicated that all three conditions provided a similar level of operational efficiency. Percentages of RLR vehicles under the flagger-only, PTS-with-flagger, and PTS-only conditions were 1.1%, 1.3%, and 3.1%, respectively. A test of proportions indicated a significant difference in the number of violat...

Alison Catarella - One of the best experts on this subject based on the ideXlab platform.

  • a real time simulation environment for evaluating traffic signal systems
    Transportation Research Record, 1998
    Co-Authors: D Bullock, Alison Catarella
    Abstract:

    Features and operating modes of the current generation of actuated controllers have evolved to the point where there is a significant difference between the configuration parameters associated with an actuated controller and the information obtained from traffic signal system optimization packages such as TRANSYT 7F and PASSER II. As a result, TRANSYT 7F and PASSER II give no guidance on the impact or sensitivity of many actuated control parameters on a traffic signal system's performance. Furthermore, none of the current generation of microscopic simulation models is detailed enough to evaluate the effect particular features, such as cycle transition algorithms or return from preemption algorithms, have on overall system performance. To address this need, an enhancement made to the CORSIM package that allows physical controllers to be connected to CORSIM is described in this paper. In this arrangement, CORSIM provides the microscopic simulation and tabulation of measures of effectiveness (MOEs). However,...

Walenty Oniszczuk - One of the best experts on this subject based on the ideXlab platform.

  • Service Strategies in Two-Server Tandem Configurations – Modeling and Investigation
    2017
    Co-Authors: Walenty Oniszczuk
    Abstract:

    In this document, two different service strategies in an Internet service station, which consists of with two separated servers (tandem), are investigated. At beginning the Internet tandem under study is first formulated as an open three-station queuing network with blocking assuming that there are finite capacity buffers at front of each server. For each Internet station configurations, the two-dimensional state graphs ware constructed and set of steady-state equations are created. These equations allow for calculating the state probabilities vectors for each tandem configurations, using an equation solving techniques. Many useful performance measures regarding the tandem configurations under study can be extracted from the steady-state probability vectors. The numerical part of this paper contains example for the investigation of different tandem configurations, where are presented the results of the calculation of the main measures of effectiveness and quality of service (QoS) parameters.

  • Blocking and Deadlocking Phenomena in Two-Server Tandem Configuration with Optional Feedback – Modeling and Parameter Sensitivity Investigation
    2016
    Co-Authors: Walenty Oniszczuk
    Abstract:

    Tandem queues provide good mathematical models of computer systems and networks, and their detailed examination is important for theory and applications. The study presented in this paper is based on performance analysis of a two-server computer network with blocking and deadlocking. New, practical results provided describe performance of a three-node Markovian queuing network with finite capacity buffers. The results highlight an area where measures of effectiveness, such as Quality of Service (QoS) are essential. In conclusion, a two-dimensional state graph is constructed, followed by a set of steady-state equations along with their probabilities for each of the states.