Signal Coordination and Arterial Capacity in Oversaturated Conditions

2000 ◽  
Vol 1727 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Ghassan Abu-Lebdeh ◽  
Rahim Benekohal
Keyword(s):  
Queue Length ◽  
Processing Capability ◽  
Signal Coordination ◽  
Capacity Loss ◽  
Explicit Function ◽  
Queue Lengths ◽  
Input Variables ◽  
Intersection System ◽  
Critical Subsystems ◽  
Critical Subsystem

Models for estimation of the capacities of oversaturated arterials were developed. The input variables in these models are capacities of individual intersections, offsets, and vehicle queue lengths. Models for quantification of capacity loss due to blockage caused by downstream queues are also presented. The proposed models show that when arterial capacity is determined in oversaturated conditions, it is not sufficient to consider only the capacities of critical intersections; instead, the capacities of critical subsystems must be considered. A critical subsystem is any two intersections plus the link that joins them where traffic processing capability is the lowest. This traffic processing capability, or critical subsystem capacity, determines the arterial capacity. It is a function of the capacities of the respective intersections, the offset between them, and the queue length on the link joining them. It is shown that a critical subsystem is not unique in that it may change location over the course of the study period. To minimize capacity loss, it is shown that offsets must be an explicit function of queue lengths. The practical use of the models was demonstrated for an oversaturated two-intersection system. The results show that improper setting of offsets can lead to significant capacity loss. In extreme cases all capacity in a given cycle may be lost if the offsets are not set properly.

scholarly journals Queue Length Forecasting in Complex Manufacturing Job Shops

Forecasting ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 322-338
Author(s):  
Marvin Carl May ◽  
Alexander Albers ◽  
Marc David Fischer ◽  
Florian Mayerhofer ◽  
Louis Schäfer ◽  
...  
Keyword(s):  
Operations Management ◽  
Queue Length ◽  
Manufacturing Systems ◽  
Production Control ◽  
Data Sets ◽  
Job Shops ◽  
Static Data ◽  
Queue Lengths ◽  
Operational Excellence

Currently, manufacturing is characterized by increasing complexity both on the technical and organizational levels. Thus, more complex and intelligent production control methods are developed in order to remain competitive and achieve operational excellence. Operations management described early on the influence among target metrics, such as queuing times, queue length, and production speed. However, accurate predictions of queue lengths have long been overlooked as a means to better understanding manufacturing systems. In order to provide queue length forecasts, this paper introduced a methodology to identify queue lengths in retrospect based on transitional data, as well as a comparison of easy-to-deploy machine learning-based queue forecasting models. Forecasting, based on static data sets, as well as time series models can be shown to be successfully applied in an exemplary semiconductor case study. The main findings concluded that accurate queue length prediction, even with minimal available data, is feasible by applying a variety of techniques, which can enable further research and predictions.

A Kalman Filter-Based Queue Length Estimation Method with Low-Penetration Mobile Sensor Data at Signalized Intersections

2018 ◽  
Vol 2672 (45) ◽  
pp. 253-264 ◽  
Author(s):  
Juyuan Yin ◽  
Jian Sun ◽  
Keshuang Tang
Keyword(s):  
Kalman Filter ◽  
Queue Length ◽  
Estimation Method ◽  
Mobile Internet ◽  
Internet Technology ◽  
Sensor Data ◽  
Linear Regression Method ◽  
Mobile Sensor ◽  
Length Estimation ◽  
Queue Lengths

Queue length estimation is of great importance for signal performance measures and signal optimization. With the development of connected vehicle technology and mobile internet technology, using mobile sensor data instead of fixed detector data to estimate queue length has become a significant research topic. This study proposes a queue length estimation method using low-penetration mobile sensor data as the only input. The proposed method is based on the combination of Kalman Filtering and shockwave theory. The critical points are identified from raw spatiotemporal points and allocated to different cycles for subsequent estimation. To apply the Kalman Filter, a state-space model with two state variables and the system noise determined by queue-forming acceleration is established, which can characterize the stochastic property of queue forming. The Kalman Filter with joining points as measurement input recursively estimates real-time queue lengths; on the other hand, queue-discharging waves are estimated with a line fitted to leaving points. By calculating the crossing point of the queue-forming wave and the queue-discharging wave of a cycle, the maximum queue length is also estimated. A case study with DiDi mobile sensor data and ground truth maximum queue lengths at Huanggang-Fuzhong intersection, Shenzhen, China, shows that the mean absolute percentage error is only 11.2%. Moreover, the sensitivity analysis shows that the proposed estimation method achieves much better performance than the classical linear regression method, especially in extremely low penetration rates.

scholarly journals Quantitative Analysis of Queue Length of Falah Roundabout (UAE, Sharjah)

2018 ◽  
Vol 3 (4) ◽  
pp. 6
Author(s):  
Emran Al Otaibi ◽  
Mohammed Refaei ◽  
Nadia Nassif ◽  
Anas Naqawa
Keyword(s):  
Queue Length ◽  
Factors Affecting ◽  
True Value ◽  
Data Regression ◽  
Field Data Collection ◽  
Term Paper ◽  
The Will ◽  
Queue Lengths ◽  
Rule Method ◽  
A Minor

Roundabouts have faced a huge development in terms of designing and operation, the reason behind that is to get the most safe and functional design. The functionality is affected by different factors e.g. line width, diameter of the roundabout etc., when the capacity of the roundabout is fully utilized, queue length starts to form in the different approaches, which indicates of a minor or major issue that should be studied. This paper discusses the different factors affecting the queue length of an approach on the roundabout (Al Falah roundabout), after obtaining the data, regression analysis was done to provide a model that can be used for estimating the volume capacity ratio from queue lengths or vice versa. Two other methods were used to compare the obtained model (HCM 2010 Method and Two Minute Rule Method), in addition to a field data collection of the actual timing needed to pass that queue length, which was assigned as the true value of the models and comparing depending on it. Finally, the discussion of the term paper, will include the different concepts of advanced statistical analysis, the will (as expected) contain different types of distributions and the coloration between the keys of the roundabouts design, and will study the limitation and how it can be improved in future.

scholarly journals A Method for Queue Length Estimation in an Urban Street Network Based on Roll Time Occupancy Data

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Dongfang Ma ◽  
Dianhai Wang ◽  
Yiming Bie ◽  
Feng Sun ◽  
Sheng Jin
Keyword(s):  
Queue Length ◽  
Estimation Model ◽  
Link Length ◽  
Urban Street ◽  
City Street ◽  
Lane Width ◽  
Relation Model ◽  
Queue Lengths ◽  
Pass Through ◽  
The Relationship

A method estimating the queue length in city street networks was proposed using the data of roll time occupancy. The key idea of this paper is that when the queue length in front of the queue detector becomes longer, the speeds of the following vehicles to pass through the detector will become smaller, resulting in higher occupancy with constant traffic intensity. Considering the relationship between queue lengths and roll time occupancy affected by many factors, such as link length, lane width, lane number, and bus ratio, twelve different conditions were designed, and the traffic data under different conditions was obtained using VISSIM simulation. Based on the analysis of simulation data, an S-type logistic model was decided to develop for the relationship between queue lengths and roll time occupancy, and the fitting equations were obtained under the twelve simulation situations. The average model for the relationship between queue lengths and roll time occupancy was presented by successive multiple linear regression with the fitting equation parameters and simulation parameters, and the estimation model for queue length was presented through analyzing the equation of the average relation model.

Adequacy of TRANSYT-7F and Synchro models along a major arterial in Saudi Arabia

2009 ◽  
Vol 36 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Nedal T. Ratrout ◽  
Maen Abdullatif Abu Olba
Keyword(s):  
Saudi Arabia ◽  
Queue Length ◽  
Optimal Timing ◽  
Signal Timing ◽  
Calibration Process ◽  
Traffic Conditions ◽  
Platoon Dispersion ◽  
Queue Lengths ◽  
The City ◽  
Optimal Signal

The TRANSYT-7F and Synchro models are used in developing optimal timing plans in the city of Al-Khobar, Saudi Arabia. This paper evaluates the adequacy of both TRANSYT-7F and Synchro under local traffic conditions by comparing queue lengths observed along a major arterial in the study area with simulated queues. The models were then calibrated to produce simulated queue lengths which are as close as possible to the observed ones. A clear difference was found between queue lengths estimated by Synchro and TRANSYT-7F. A queue length calibration process was accomplished for TRANSYT-7F by using platoon dispersion factor values of 20 and 35 for through and left-turning traffic, respectively. Synchro calibration was unsatisfactory. The simulated queue lengths could not be calibrated in a meaningful way to resemble the observed queue lengths. Regardless of this, both models produced comparable optimal signal timing plans.

Strong Approximations of Irreducible Closed Queueing Networks

1997 ◽  
Vol 29 (2) ◽  
pp. 498-522 ◽  
Author(s):  
Hanqin Zhang
Keyword(s):  
Queueing Networks ◽  
Queue Length ◽  
Rates Of Convergence ◽  
Closed Queueing Networks ◽  
Brownian Motions ◽  
Strong Approximations ◽  
Queue Lengths

A sequence of irreducible closed queueing networks is considered in this paper. We obtain that the queue length processes can be approximated by reflected Brownian motions. Using these approximations, we get rates of convergence of the distributions of queue lengths.

The probability of large queue lengths and waiting times in a heterogeneous multiserver queue II: Positive recurrence and logarithmic limits

1995 ◽  
Vol 27 (2) ◽  
pp. 567-583 ◽  
Author(s):  
John S. Sadowsky
Keyword(s):  
Waiting Time ◽  
Queue Length ◽  
Waiting Times ◽  
General Setting ◽  
Batch Arrival ◽  
Positive Recurrence ◽  
Waiting Time Distributions ◽  
Harris Recurrence ◽  
Stationary Queue Length ◽  
Queue Lengths

We continue our investigation of the batch arrival-heterogeneous multiserver queue begun in Part I. In a general setting we prove the positive Harris recurrence of the system, and with no additional conditions we prove logarithmic tail limits for the stationary queue length and waiting time distributions.

Queues with time-dependent arrival rates. III — A mild rush hour

1968 ◽  
Vol 5 (3) ◽  
pp. 591-606 ◽  
Author(s):  
G. F. Newell
Keyword(s):  
Queueing Theory ◽  
Queue Length ◽  
Arrival Rate ◽  
Time Dependent ◽  
Service Rate ◽  
Diffusion Approximations ◽  
Dimensionless Form ◽  
Queue Lengths ◽  
The Mean ◽  
Mean Queue Length

The arrival rate of customers to a service facility is assumed to have the form λ(t) = λ(0) — βt2 for some constant β. Diffusion approximations show that for λ(0) sufficiently close to the service rate μ, the mean queue length at time 0 is proportional to β–1/5. A dimensionless form of the diffusion equation is evaluated numerically from which queue lengths can be evaluated as a function of time for all λ(0) and β. Particular attention is given to those situations in which neither deterministic queueing theory nor equilibrium stochastic queueing theory apply.

scholarly journals Investingating the Effect of Signal Coordination on Delay Time: Case Study Mazer-e-Sharif, Afghanistan

2019 ◽  
Vol 2 (3) ◽  
pp. 1152-1166
Author(s):  
Hakan Aslan ◽  
Suhrab Ahadi
Keyword(s):  
Delay Time ◽  
Service Level ◽  
Geometric Design ◽  
Signal Coordination ◽  
Traffic Characteristics ◽  
Delay Times ◽  
Total Vehicle ◽  
Coordination System ◽  
Queue Lengths

In this study; delay times and queue length parameters were analysed for the new structure obtained by revising the current geometric situation and signalling system at two intersections in an important city of Afghanistan, Mezar-i-Sheriff, using two different VISSIM and SIDRA softwares. In addition to present and improved geometry scenarios, the traffic characteristics of the current and future cases to improve the service level of the network by reducing delay time and queue lengths through signal coordination were also investigated. According to the analytical findings of the study, it was found that if the coordination is carried out between the first and the second intersection of Marmul Street before the improved geometric design, the total vehicle delays for the system decreased by up to 3.36 percent. After improving the geometric design, total vehicle delays for the system decreased by up to 8.85 percent. When the current and the improved situation are compared, it was seen that, in the improved case, the delays in the total vehicle delays for the pre-coordination and after coordination system (network) decreased 51.78 and 54.51 percent, respectively.

scholarly journals Modelling of Queue Length in Freeway Work Zones – Case Study Karaj-Tehran Freeway

2021 ◽  
Vol 33 (1) ◽  
pp. 49-59
Author(s):  
Mojtaba Mousazadeh Gilandeh ◽  
Sari Sharif Ali ◽  
Mohammad Javad Goodarzi ◽  
Nahid Amini ◽  
Hassan Latifi
Keyword(s):  
Flow Rate ◽  
Queue Length ◽  
Abrupt Change ◽  
Heavy Vehicles ◽  
Work Zones ◽  
Maintenance And Rehabilitation ◽  
Abrupt Changes ◽  
Queue Lengths ◽  
Freeway Work Zones

In this study, the traffic parameters were collected from three work zones in Iran in order to evaluate the queue length in the work zones. The work zones were observed at peak and non-peak hours. The results showed that abrupt changes in Freeway Free Speed (FFS) and arrival flow rate caused shockwaves and created a bottleneck in that section of the freeway. In addition, acceleration reduction, abrupt change in the shockwave speed, abrupt change in the arrival flow rate and increase in the percentage of heavy vehicles have led to extreme queue lengths and delay. It has been found that using daily traffic data for scheduling the maintenance and rehabilitation projects could diminish the queue length and delay. Also, by determining the bypass for heavy vehicles, the delay can be significantly reduced; by more than three times. Finally, three models have been presented for estimating the queue length in freeway work zones. Moreover, the procedure shown for creating a queue length model can be used for similar freeways.

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