scholarly journals Pedestrian Delay Model for Continuous Flow Intersections under Three Design Patterns

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Tao Wang ◽  
Jing Zhao ◽  
Chaoyang Li
Keyword(s):  
Sensitivity Analysis ◽  
Continuous Flow ◽  
Design Patterns ◽  
Level Of Service ◽  
Optimized Design ◽  
Delay Model ◽  
Key Factors ◽  
Traffic Demand ◽  
Demand Pattern ◽  
Delay Models

In order to accurately evaluate the level of service of pedestrians and provide the basis for the optimized design, the pedestrian delay of the continuous flow intersection was analyzed. According to the characteristics of streams of pedestrians’ arriving and leaving, the pedestrian delay models of different directions (namely, straight and diagonal) were established for three pedestrian passing patterns of the continuous flow intersection. The accuracy of the models was verified by VISSIM. The deviation was less than 3%. The effects of three key factors, namely, the vehicle demands, pedestrian demands and percentage of diagonal crossing, on the delay of the pedestrian under three modes were discussed by sensitivity analysis. The results show that the traditional pedestrian passing pattern mainly applies on the conditions that vehicle and pedestrian demands are low. The pattern of interspersed pedestrian passing is mainly applicable to the conditions of high vehicle and pedestrian demands. Although the pattern of exclusive pedestrian passing phase was least selected as the optimal design, it can apply to traffic demand fluctuating condition for its insensitive to volume and pedestrian demand pattern.

Ranking and Sensitivity Analysis of Key Factors for Successful Project Management Performance: An Application of AHP for Oil and Gas Sector

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Farhaj Ishtiaq ◽  
Mirza Jahanzaib
Keyword(s):  
Sensitivity Analysis ◽  
Project Management ◽  
Analytical Hierarchy Process ◽  
Oil And Gas ◽  
Planning Process ◽  
Project Planning ◽  
Key Factors ◽  
Management Performance ◽  
Hierarchy Process ◽  
Oil And Gas Sector

<p>Complexities faced by oil and gas projects due to uncertainty and risk, demand the implementation of project management techniques for their successful completion. Therefore, this is made by using analytical hierarchy process, to identify and prioritize the key factors for successful project management performance of oil and gas projects. These factors are categorized into three groups which include attributes of project staff, project planning process and assessment of project quality. Using expert choice, a hierarchy is developed followed by pairwise comparison based upon data collection from industrial experts of oil and gas sector. Results of analytical hierarchy process (AHP) concluded that, project completion within estimated time and budget, clarity of objectives and involvement of top management are most crucial elements for improvement in project management performance of oil and gas projects. Whereas sensitivity analysis being carried out according to three different scenarios highlighted factors according to their relative importance.</p>

Design and Performance Analysis of Pedestrian Crossing Facilities for Continuous Flow Intersections

2005 ◽  
Vol 1939 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Ramanujan Jagannathan ◽  
Joe G. Bared
Keyword(s):  
Continuous Flow ◽  
Level Of Service ◽  
Vehicular Traffic ◽  
Average Delay ◽  
Qualitative And Quantitative ◽  
Traffic Performance ◽  
Pedestrian Traffic ◽  
Pedestrian Level Of Service ◽  
And Performance ◽  
Pedestrian Crossing

Although concepts of the continuous flow intersection (CFI) have been around for approximately four decades, minimal or no literature describing studies that have analyzed pedestrian traffic performance at these intersections is available. Several studies have reported on the qualitative and quantitative benefits for the vehicular traffic performance of CFIs in comparison with the benefits for the vehicular traffic performance of conventional intersections but have provided minimal or no discussion about pedestrian traffic performance. As a novel intersection design, many important considerations are required to design pedestrian accesses and crossings at CFIs without compromising pedestrian safety and vehicular traffic performance. In this paper, the design methodologies for providing pedestrian access and related pedestrian signal timings are discussed. Modeling was conducted on three typical geometries for CFIs with base signal timings optimized for vehicular traffic performance. The results indicate an acceptable pedestrian level of service of B or C on the basis of the average delay per stop experienced by any pedestrian for pedestrian crossings at the typical CFI geometries modeled. All pedestrians served at the CFIs are accommodated within two cycles for a typical signal cycle length ranging from 60 to 100 s.

scholarly journals Cost-Benefit Analysis under the DSM Model of Green Lighting

2018 ◽  
pp. 149-155
Author(s):  
Yanjiang GONG ◽  
Jiang LI ◽  
Wenshuang YU ◽  
Runbing YANG ◽  
Tiejun ZHOU
Keyword(s):  
Sensitivity Analysis ◽  
Association Rules ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Benefit Analysis ◽  
Key Factors ◽  
Factors Affecting ◽  
Subsidy Rate ◽  
Willingness To Use ◽  
The Cost

Based on the concept of DSM and the requirements of the demonstration project, the DSM model of green lighting was studied, carrying out the cost-benefit analysis. Combining the characteristics of the demonstration area, first of all, the cost-benefit of different interest subjects was analyzed. Secondly, the association rules algorithm was analyzed in detail, and the cost-benefit was analyzed by the association rules algorithm. Finally, the sensitivity analysis of the key factors, affecting the cost and benefit of each interest subject, was done by using the algorithm. And it is concluded that the user subsidy rate and consumer electricity price are the key factors that affect the userТs willingness to use green lighting technology and power grid enterprises to implement DSM measures.

scholarly journals Traffic Demands Policies Effect on Congestion, Delay and Fuel Consumption

2020 ◽  
Vol 9 (5) ◽  
pp. 521-527
Keyword(s):  
Fuel Consumption ◽  
Expert Panel ◽  
Demand Management ◽  
Level Of Service ◽  
System Management ◽  
Transportation Demand ◽  
Traffic Demand ◽  
Study Case ◽  
The Government ◽  
Reduction Percentage

Traffic demands on Jordanian streets have been affected by the increasing human population and the number of vehicles. This study aims to apply transportation demand management (TDM) techniques to improve the level of service (LOS). The study employs both TDM and transportation system management (TSM). In order to investigate what type of strategies to be considered a questionnaire is used. The acceptance degrees of the TDM and TSM groups were measured via the questionnaires using SPSS version 20. The selected policies then are used on a certain location as a study case in Amman city; an intersection is connecting two urban main streets. The used policies have a reduction percentage in traffic demands which is expected throughout an expert panel. The results show that delay and fuel consumption are indeed reduced; however, this does not lead to any considerable improvement in the LOS. The LOS was enhanced when the reduction in traffic demand reached 20% with an increase in capacity achieved by adding 3 new lanes. The fuel consumption and delays were measured to be about 35% less with growth rate of 8% for the coming five years. This study is expected to help popularize TDM policies in place of other solutions so that inexpensive measures can be adopted by the government.

Design Factors Effecting Capacity of Rail and Transit Systems

2012 ◽  
Author(s):  
David F. Thurston
Keyword(s):  
Control Design ◽  
System Capacity ◽  
Optimized Design ◽  
Signal System ◽  
Key Factors ◽  
Transit Systems ◽  
Vehicle Type ◽  
Train Control ◽  
Rail Line ◽  
Design Factors

The overall impact on system “capacity” is typically described in terms of train control design. There are several other key factors that determine the ultimate system capacity of a rail line. Among the most influential of these are: vehicle type and configuration, stations and platform design and configuration, and overall civil alignment. In the analysis of the maximum capacity delivered from the train control system, all of these require optimization of design to achieve the highest throughput, and have a direct influenced by train control design as well. This paper describes how fully optimized design of non train control issues and factors have an impact on signal system design and have a consequence that is permanent once constructed.

Fuel-Sensitive Ignition Delay Models for a Local and Global Description of Direct Injection Internal Combustion Engines

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Kyoung Hyun Kwak ◽  
Claus Borgnakke ◽  
Dohoy Jung
Keyword(s):  
Ignition Delay ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Cetane Number ◽  
Global Model ◽  
Local Model ◽  
Delay Model ◽  
Lower Accuracy ◽  
Delay Models ◽  
Single Calibration

Models for ignition delay are investigated and fuel-specific properties are included to predict the effects of different fuels on the ignition delay. These models follow the Arrhenius type expression for the ignition delay modified with the oxygen concentration and Cetane number to extend the range of validity. In this investigation, two fuel-sensitive spray ignition delay models are developed: a global model and a local model. The global model is based on the global combustion chamber charge properties including temperature, pressure, and oxygen/fuel content. The local model is developed to account for temporal and spatial variations in properties of separated spray zones such as local temperature, oxidizer, and fuel concentrations obtained by a quasi-dimensional multizone fuel spray model. These variations are integrated in time to predict the ignition delay. Often ignition delay models are recalibrated for a specific fuel but in this study, the global ignition delay model includes the Cetane number to capture ignition delay of various fuels. The local model uses Cetane number and local stoichiometric oxygen to fuel molar ratio. The model is therefore capable of predicting spray ignition delays for a set of fuels with a single calibration. Experimental dataset of spray ignition delay in a constant volume chamber is used for model development and calibration. The models show a good accuracy for the predicted ignition delay of four different fuels: JP8, DF2, n-heptane, and n-dodecane. The investigation revealed that the most accurate form of the models is from a calibration done for each individual fuel with only a slight decrease in accuracy when a single calibration is done for all fuels. The single calibration case is the more desirable outcome as it leads to general models that cover all the fuels. Of the two proposed models, the local model has a slightly better accuracy compared to the global model. Results for both models demonstrate the improvements that can be obtained for the ignition delay model when additional fuel-specific properties are included in the spray ignition model. Other alternative fuels like synthetic oxygenated fuels were included in the investigation. These fuels behave differently such that the Cetane number does not provide the same explanation for the trend in ignition delay. Though of lower accuracy, the new models do improve the predictive capability when compared with existing types of ignition delay models applied to this kind of fuels.

Validation of Generalized Delay Model for Oversaturated Conditions

1997 ◽  
Vol 1572 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Roelof J. Engelbrecht ◽  
Daniel B. Fambro ◽  
Nagui M. Rouphail ◽  
Aladdin A. Barkawi
Keyword(s):  
Simulation Model ◽  
Close Agreement ◽  
Signalized Intersections ◽  
Delay Model ◽  
Traffic Operations ◽  
Microscopic Simulation ◽  
Highway Capacity ◽  
Traffic Demand ◽  
Highway Capacity Manual ◽  
The U.S

With today’s ever-increasing traffic demand, more and more signalized intersections are experiencing congestion for longer periods of time. To better quantify oversaturated conditions, it is necessary to accurately estimate oversaturation delay. The generalized delay model, proposed for inclusion in the next update of the U.S. Highway Capacity Manual (HCM), is introduced here. The generalized delay model differs from the model in the 1994 edition of the HCM as it is sensitive to the duration of the analysis period and is not restricted to degrees of saturation less than 1.2. The TRAF-NETSIM microscopic simulation model was used to verify the generalized delay equation for oversaturated conditions. A simulation model was used, because it is extremely difficult to measure oversaturated delay in the field. The study was designed to cover as much of the domain of oversaturated traffic operations as possible. The variability in simulated delays was investigated, and an equation was developed to predict the standard deviation of oversaturated delay estimates. It was found that delays estimated by the proposed generalized delay model are in close agreement with those simulated by TRAF-NETSIM. On average, simulated delays are overestimated slightly, but the error is small compared with actual delays. The proposed generalized delay model is expected to provide a good estimate of actual oversaturation delays that occur in the field.

scholarly journals The Credibility Revolution in Empirical Economics: How Better Research Design is Taking the Con out of Econometrics

2010 ◽  
Vol 24 (2) ◽  
pp. 3-30 ◽  
Author(s):  
Joshua D Angrist ◽  
Jörn-Steffen Pischke
Keyword(s):  
Sensitivity Analysis ◽  
Research Design ◽  
Empirical Work ◽  
Random Assignment ◽  
Key Factors ◽  
Empirical Microeconomics ◽  
Empirical Economics ◽  
Research Designs ◽  
Good Research

Since Edward Leamer's memorable 1983 paper, “Let's Take the Con out of Econometrics,” empirical microeconomics has experienced a credibility revolution. While Leamer's suggested remedy, sensitivity analysis, has played a role in this, we argue that the primary engine driving improvement has been a focus on the quality of empirical research designs. The advantages of a good research design are perhaps most easily apparent in research using random assignment. We begin with an overview of Leamer's 1983 critique and his proposed remedies. We then turn to the key factors we see contributing to improved empirical work, including the availability of more and better data, along with advances in theoretical econometric understanding, but especially the fact that research design has moved front and center in much of empirical micro. We offer a brief digression into macroeconomics and industrial organization, where progress—by our lights—is less dramatic, although there is work in both fields that we find encouraging. Finally, we discuss the view that the design pendulum has swung too far. Critics of design-driven studies argue that in pursuit of clean and credible research designs, researchers seek good answers instead of good questions. We briefly respond to this concern, which worries us little.

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