Modification of Traffic Wave Theory and the Development of a New Stop-Wave Model

2012 ◽  
Vol 253-255 ◽  
pp. 1615-1618
Author(s):  
Yu Han Jia ◽  
Jian Ping Wu ◽  
Yi Man Du
Keyword(s):  
Wave Phenomenon ◽  
Wave Model ◽  
Wave Theory ◽  
Signalized Intersections ◽  
Microscopic Level ◽  
Peak Period ◽  
Traffic Flow Theory ◽  
Traffic State ◽  
Traffic Wave ◽  
Real Traffic

This paper studies the traffic wave phenomenon on the basis of traffic flow theory and finds that the classical theory disagreeing with the real traffic state. The existing theory is modified and a new traffic wave model is proposed based on the improved theory. The aim of the model is to better describe the stop-wave phenomenon in signalized intersections at a microscopic level. Then the model is calibrated and validated by data obtained from an intersection during morning-peak period. Results show this new model can represent the characteristics of traffic wave with a high accuracy and can demonstrate the improved traffic wave theory.

scholarly journals The Departure Characteristics of Traffic Flow at the Signalized Intersection

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Zhaowei Qu ◽  
Yan Xing ◽  
Hongyu Hu ◽  
Yuzhou Duan ◽  
Xianmin Song ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Wave Model ◽  
Wave Theory ◽  
Signalized Intersection ◽  
Departure Process ◽  
Dispersion Process ◽  
Spatiotemporal Model ◽  
Quantitative Calculation ◽  
Traffic Wave ◽  
Motion Characteristics

The motion characteristics of the leading vehicle and the following vehicles of the traffic flow at the typical urban intersections are qualitatively analyzed through the kinematical equation and the traffic wave theory. Then, the motion characteristic of the whole traffic flow during the dispersion process is also studied. Based on the spatiotemporal model of kinematics in the departure process and traffic wave model in the dispersion process proposed, the change of the leading vehicle of the departure process and the time of the following vehicles reaching to the stable speed as well as the relationship between the green time and the departure vehicle number at the intersection are acquired. Furthermore, according to the qualitative analysis and the quantitative calculation of the departure traffic flow at the signalized intersection, the dispersion characteristic of traffic flow at the signalized intersection was studied and analyzed, which provides reliable theoretical basis for traffic signal setting at the intersection.

scholarly journals Road Impedance Model Study under the Control of Intersection Signal

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yunlin Luo ◽  
Na Wang ◽  
Huaikun Xiang ◽  
Jinhu Wang
Keyword(s):  
Road Traffic ◽  
Wave Model ◽  
Wave Theory ◽  
Urban Traffic ◽  
Percentage Error ◽  
Route Guidance ◽  
Absolute Deviation ◽  
Impedance Model ◽  
Proposed Model ◽  
Traffic Wave

Road traffic impedance model is a difficult and critical point in urban traffic assignment and route guidance. The paper takes a signalized intersection as the research object. On the basis of traditional traffic wave theory including the implementation of traffic wave model and the analysis of vehicles’ gathering and dissipating, the road traffic impedance model is researched by determining the basic travel time and waiting delay time. Numerical example results have proved that the proposed model in this paper has received better calculation performance compared to existing model, especially in flat hours. The values of mean absolute percentage error (MAPE) and mean absolute deviation (MAD) are separately reduced by 3.78% and 2.62 s. It shows that the proposed model has feasibility and availability in road traffic impedance under intersection signal.

scholarly journals Research on the impact of ship traffic flow on the restricted channel segment of the middle Yangtze River based on traffic wave theory

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Ting Liu ◽  
Gabriel Lodewijks
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Flow Simulation ◽  
Wave Theory ◽  
Flow Density ◽  
List Type ◽  
Ship Traffic ◽  
Traffic Wave ◽  
The Impact ◽  
Channel Segment

Abstract Abstract On the basis of the influence of dry season on ship traffic flow, the gathering and dissipating process of ship traffic flow was researched with Greenshields linear flow—density relationship model, the intrinsic relationship between the ship traffic congestion state and traffic wave in the unclosed restricted channel segment was emphatically explored when the ship traffic flow in a tributary channel inflows, and the influence law of multiple traffic waves on the ship traffic flow characteristics in unclosed restricted segment is revealed. On this basis, the expressions of traffic wave speed and direction, dissipation time of queued ships and the number of ships affected were provided, and combined with Monte Carlo method, the ship traffic flow simulation model in the restricted channel segment was built. The simulation results show that in closed restricted channel segment the dissipation time of ships queued is mainly related to the ship traffic flow rate of segments A and C, and the total number of ships affected to the ship traffic flow rate of segment A. And in unclosed restricted channel segment, the dissipation time and the total number of ships affected are also determined by the meeting time of the traffic waves in addition to the ship traffic flow rate of segments. The research results can provide the theoretical support for further studying the ship traffic flow in unclosed restricted channel segment with multiple tributaries Article Highlights The inflow of tributaries' ship traffic flows has an obvious impact on the traffic conditions in the unenclosed restricted channel segment. The interaction and influence between multiple ship traffic waves and the mechanism of generating new traffic waves are explained. The expression of both dissipation time of queued ships and the total number of ships affected in the closed and unclosed restricted channel segment are given.

Application of Traffic-Wave Theory in Air Traffic Flow

Logistics ◽  
2009 ◽  
Author(s):  
Zhaoning Zhang ◽  
Xinhua Li ◽  
Lili Wang
Keyword(s):  
Traffic Flow ◽  
Wave Theory ◽  
Air Traffic ◽  
Air Traffic Flow ◽  
Traffic Wave

Assessing Climate Change in the North Atlantic Wave Regimes

2020 ◽  
Author(s):  
M. Bernardino ◽  
M. Gonçalves ◽  
C. Guedes Soares
Keyword(s):  
System Integration ◽  
Wave Model ◽  
Offshore Structures ◽  
Future Climate ◽  
Wave Direction ◽  
Peak Period ◽  
Significant Wave ◽  
The North ◽  
Wave Heights ◽  
Mean Wave Period

Abstract An improved understanding of the present and future marine climatology is necessary for numerous activities, such as operation of offshore structures, optimization of ship routes and the evaluation of wave energy resources. To produce global wave information, the WW3 wave model was forced with wind and ice-cover data from an RCP8.5 EC-Earth system integration for two 30-year time slices. The first covering the periods from 1980 to 2009 represents the present climate and the second, covering the periods from 2070–2099, represents the climate in the end of the 21st century. Descriptive statistics of wind and wave parameters are obtained for different 30-year time slices. Regarding wind, magnitude and direction will be used. For wave, significant wave height (of total sea and swell), mean wave period, peak period, mean wave direction and energy will be investigated. Changes from present to future climate are evaluated, regarding both mean and extreme events. Maps of the theses statistics are presented. The long-term monthly joint distribution of significant wave heights and peak periods is generated. Changes from present to future climate are assessed, comparing the statistics between time slices.

scholarly journals A Kinematic Wave Model of Glacier Surges

1972 ◽  
Vol 11 (61) ◽  
pp. 65-72
Author(s):  
Andrew C. Palmer
Keyword(s):  
Wave Model ◽  
Wave Theory ◽  
Kinematic Wave ◽  
Highway Traffic ◽  
External Disturbances ◽  
Ice Flow ◽  
Slowing Down ◽  
Kinematic Waves ◽  
Glacier Surges ◽  
Kinematic Wave Model

AbstractThe existing theory of kinematic waves on glaciers does not account for self-induced instability of the flow, or for surges which are not the result of external disturbances. Surges do however have much in common with kinematic waves. Unstable behaviour of glaciers can be explained by a straightforward modification of kinematic wave theory. In this modification the relation between the ice flow and the ice depth is not the same when the ice is accelerating as when it is slowing down. A similar effect has previously been shown to explain observed instabilities in the flow of highway traffic, a phenomenon which is otherwise adequately described by a simple kinematic wave theory.

scholarly journals The impact of wave physics in the CMEMS-IBI ocean system Part A: Wave forcing validation

2019 ◽  
Author(s):  
Romain Rainaud ◽  
Lotfi Aouf ◽  
Alice Dalphinet ◽  
Marcos Garcia Sotillo ◽  
Enrique Alvarez-Fanjul ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
Wave Spectrum ◽  
Circulation Model ◽  
Wave Model ◽  
Heat Fluxes ◽  
Wave System ◽  
Peak Period ◽  
Wave Forecast ◽  
High Frequency Waves ◽  
The Impact

Abstract. The Iberian Biscay Ireland (IBI) wave system has the challenge to improve wave forecast and the coupling with ocean circulation model dedicated to western european coast. The momentum and heat fluxes at the sea surface are strongly controlled by the waves and there is a need of using accurate sea state from wave model. This work describes the more recent version of the IBI wave system and highlight the performance of system in comparison with satellite altimeters and buoys wave data. The validation process has been performed for 1-year run of the wave model MFWAM with boundary conditions provided by the global wave system. The results show on the one hand a slightly improvement on significant wave height and peak period, and on the other hand a better surface stress for high wind conditions. This latter is a consequence of using a tail wave spectrum shaped as the Philipps wave spectrum for high frequency waves.

Reconstruction of Ocean Surfaces From Randomly Distributed Measurements Using a Grid-Based Method

2021 ◽  
Author(s):  
Nicolas Desmars ◽  
Moritz Hartmann ◽  
Jasper Behrendt ◽  
Marco Klein ◽  
Norbert Hoffmann
Keyword(s):  
Wave Model ◽  
Wave Theory ◽  
Linear Wave ◽  
Surface Dynamics ◽  
Wave Measurements ◽  
Model Parameterization ◽  
Grid Points ◽  
High Flexibility ◽  
Similar Accuracy ◽  
Grid Based

Abstract In view of deterministic ocean wave prediction, we introduce and investigate a new method to reconstruct ocean surfaces based on randomly distributed wave measurements. Instead of looking for the optimal parameters of a wave model through the minimization of a cost function, our approach directly solves the free surface dynamics — coupled with an interpolation operator — for the quantities of interest (i.e., surface elevation and velocity potential) at grid points that are used to compute the relevant operators. This method allows a high flexibility in terms of desired accuracy and ensures the physical consistency of the solution. Using the linear wave theory and unidirectional wave fields, we validate the applicability of the proposed method. In particular, we show that our grid-based method is able to reach similar accuracy than the wave-model parameterization method at a reasonable cost.

A Methodology to Simulate Floating Offshore Operations Using a Design Wave Theory

2005 ◽  
Vol 128 (4) ◽  
pp. 304-313 ◽  
Author(s):  
Lee O’Neill ◽  
Emmanuel Fakas ◽  
Mark Cassidy
Keyword(s):  
Oil And Gas ◽  
Wave Model ◽  
Wave Theory ◽  
Contact Forces ◽  
Efficient Manner ◽  
North West ◽  
The North ◽  
Large Numbers ◽  
Cost Efficient ◽  
Offshore Operations

Numerical techniques are extensively used to predict vessel motions and associated contact forces for offshore operations such as lift and floatover deck installations. The accuracy of such predictions however is highly dependent on the comprehensive modeling of sea state conditions, which is often limited by computational power and time constraints. A time-efficient methodology, suitable for modeling large numbers of installation sea states, is developed to alleviate this problem. The methodology is based on the Constrained New Wave model which has been previously used to overcome similar problems. However this has only been for individual, extreme storm conditions. The accuracy, time-efficiency, and practicality of the revised methodology is demonstrated by means of direct comparison of simulation results obtained for a floatover deck installation on the North West Shelf of Australia. The ability to perform a large number of simulations in a time and cost efficient manner is of paramount importance in assessing the system limitations to varying installation conditions, a case that has always been challenging to designers during the development of oil and gas projects. Such flexibility improves confidence in the overall system, necessary for the accurate assessment of the commercial viability of marginal developments.

scholarly journals Wave run-up on embayed beaches. Study case: Itapocorói Bay, Southern Brazil

2017 ◽  
Vol 65 (2) ◽  
pp. 187-200 ◽  
Author(s):  
Guilherme Vieira da Silva ◽  
Paula Gomes da Silva ◽  
Rafael Sangoi Araujo ◽  
Antonio Henrique da Fontoura Klein ◽  
Elírio E. Toldo Jr.
Keyword(s):  
Wave Height ◽  
Wave Model ◽  
Swash Zone ◽  
Southern Brazil ◽  
Wave Direction ◽  
Linear Processes ◽  
Similarity Parameter ◽  
Peak Period ◽  
The Mean ◽  
Run Up

ABSTRACT This paper presents a new approach for estimating run-up on embayed beaches based on a study of the microtidal coast of Itapocorói Bay, Southern Brazil using the surf similarity parameter and wave height at break location. The four step methodology involved: 1) direct wave measurement (34 days), wave run-up measurement (19 days at 7 points within the bay), measurement of bathymetry and beach topography in the entire bay; 2) tests on available formulae to calculate wave run-up; 3) use of the SWAN spectral wave model to simulate wave parameters at breaking at each wave run-up measurement point and; 4) development of a new formula/approach to assess wave run-up on embayed beaches (in both exposed and protected areas). During the experiments the significant wave height varied from 0.5 m to 3.01 m, the mean wave period from 2.79 s to 7.76 s (the peak period varied between 2.95 s and 17.18 s), the mean wave direction from 72.5° to 141.9° (the peak direction varied from 39.2° to 169.8°) and the beach slope (tan β) from 0.041 to 0.201. The proposed formula is in good agreement with measured data for different wave conditions and varying degrees of protection. The analysis demonstrates that although R² varies from 0.52 to 0.75, the wave run-up distribution over the measurements agreed well with the proposed model, as shown by quantile-quantile analysis (R²=0.98 to 0.99). The errors observed in individual cases may be related to errors of measurements, modeling and to non-linear processes in the swash zone, such as infragavity waves.

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