Dynamic congested traffic states of lattice hydrodynamic model with an on-ramp and its immediate upstream off-ramp

2018 ◽  
Vol 32 (29) ◽  
pp. 1850325 ◽  
Author(s):  
Tao Wang ◽  
Jing Zhang ◽  
Shubin Li ◽  
Haoming Du ◽  
Ge Gao

This paper investigates the features of congested traffic flow near the combination of off-ramp and on-ramp. Firstly, the stochastic off-ramp and on-ramp are designed. Then, a two-lane lattice hydrodynamic traffic flow model coupled with a combination bottleneck is proposed to reproduce the empirical phenomena. In the simulation, the asymmetric-lane change rules were adopted, and many congested traffic flow patterns were observed near the combination bottlenecks, such as homogeneous synchronized traffic (HST), moving localized cluster (MLC), triggered stop-and-go traffic (TSG), oscillating congested traffic (OCT), pinned localized cluster (PLC), and homogeneous congested traffic (HCT). The obtained simulation results suggest that the proposed model is good and can produce the observed congestion spatiotemporal traffic patterns well.

2019 ◽  
Vol 9 (14) ◽  
pp. 2848 ◽  
Author(s):  
Zawar H. Khan ◽  
Waheed Imran ◽  
Sajid Azeem ◽  
Khurram S. Khattak ◽  
T. Aaron Gulliver ◽  
...  

A new macroscopic traffic flow model is proposed, which considers driver presumption based on driver reaction and traffic stimuli. The Payne–Whitham (PW) model characterizes the traffic flow based on a velocity constant C 0 which results in unrealistic density and velocity behavior. Conversely, the proposed model characterizes traffic behavior with velocities based on the distance headway. The performance of the proposed and PW models is evaluated over a 300 m circular road for an inactive bottleneck. The results obtained show that the traffic behavior with the proposed model is more realistic.


2003 ◽  
Vol 1852 (1) ◽  
pp. 209-219 ◽  
Author(s):  
Stéphane Chanut ◽  
Christine Buisson

A new first-order traffic flow model is introduced that takes into account the fact that various types of vehicles use the roads simultaneously, particularly cars and trucks. The main improvement this model has to offer is that vehicles are differentiated not only by their lengths but also by their speeds in a free-flow regime. Indeed, trucks on European roads are characterized by a lower speed than that of cars. A system of hyperbolic conservation equations is defined. In this system the flux function giving the flow of heavy and light vehicles depends on total and partial densities. This problem is partly solved in the Riemann case in order to establish a Godunov discretization. Some model output is shown stressing that speed differences between the two types of vehicles and congestion propagation are sufficiently reproduced. The limits of the proposed model are highlighted, and potential avenues of research in this domain are suggested.


Author(s):  
Behrang Asadi ◽  
Chen Zhang ◽  
Ardalan Vahidi

A vehicle’s untimely arrival at a local traffic wave with lots of stops and goes increases its fuel use. This paper proposes predictive planning of the vehicle velocity for reducing the velocity transients in upcoming traffic waves. Macroscopic evolution of traffic pattern along the vehicle route is first estimated by combining a traffic flow model. The fuel optimal velocity trajectory is calculated by solving an optimal control problem with the spatiotemporally varying constraint imposed by the traffic. Preliminary simulation results indicate the potential for improvement in fuel economy with a little compromise on travel time.


2012 ◽  
Vol 241-244 ◽  
pp. 2072-2075
Author(s):  
Jing Shan Pan ◽  
Li Dong Zhang

Traffic overflow has great negative impact on normal traffic flow. Improper time setting and offset, even more right turn input traffic flow can cause this extreme phenomenon. In order to discover the intrinsic factor and relationship between overflow and signal setting, traffic flow incoming, we build the traffic flow model. This model takes two adjacent crosses as example, and to count the remained traffic flow queue length in given time interval. The simulation results prove our model’s feasibility. Our model well helps us to understand the overflow characteristics and to find the effective solution to conquer it in the future.


2002 ◽  
Vol 1802 (1) ◽  
pp. 214-224
Author(s):  
Huajing Shi ◽  
Athanasios K. Ziliaskopoulos

A microscopic traffic flow model based on the constant-time-headway policy and McRuer’s man-machine crossover model was designed. Automatic control theory concepts were employed in the model formulation. The constant-time-headway policy was used to generate the command model of a human driver’s decision for vehicle acceleration or deceleration. This command is the input signal fed into the driver-vehicle dynamics suggested by the crossover model. The proposed model was mathematically formulated, designed, implemented, and numerically simulated. The stability properties and validity of the proposed model were analyzed on the basis of the simulation results. It was demonstrated that the proposed model can reproduce well-known traffic phenomena such as shock waves, intersection starting and stopping waves, and loop structures of flow-density and speed-density plots.


2017 ◽  
Vol 31 (09) ◽  
pp. 1750090 ◽  
Author(s):  
Yongfu Li ◽  
Wenbo Chen ◽  
Srinivas Peeta ◽  
Xiaozheng He ◽  
Taixiong Zheng ◽  
...  

This study proposes a new microscopic traffic flow model based on the spring-mass system theory. In particular, considering the similarity between the acceleration or deceleration behavior in traffic flow and the scaling properties of a spring, a car-following (CF) model is proposed based on the fundamental physical law of the spring-mass system. Stability of the proposed model is analyzed using the perturbation method to obtain the stability condition. Numerical experiments are performed through simulation. The results demonstrate the proposed model can capture the characteristic of propagation backwards of disturbance in traffic flow. In addition, the findings of this study provide insights in modeling traffic flow from the mechanical system theory perspective.


2009 ◽  
Vol 20 (10) ◽  
pp. 1537-1546 ◽  
Author(s):  
TIE-QIAO TANG ◽  
YAN LI ◽  
HAI-JUN HUANG

Taxi will come to one complete halt during the boarding/alighting period and might produce stop-and-go without passengers, so it often produces traffic interruption on the single-lane system. Tang et al. pointed out that the traffic flow model [Chin. Phys.18, 975 (2009)] can be used to directly describe various micro phenomena resulted by traffic interruption on the single-lane system, if we properly define the traffic interruption probability, so in this paper we adopt this model to study the micro phenomena resulted by taxi on the single-lane system. The numerical results show that this model can describe the effects that taxi has on the trails of each vehicle's motion and the evolutions of the flow and the density on the single-lane system, but that these effects are relevant to the initial conditions of the whole system.


2015 ◽  
Vol 26 (03) ◽  
pp. 1550032 ◽  
Author(s):  
Qi-Lang Li ◽  
Rui Jiang ◽  
Zhong-Jun Ding ◽  
Jie Min ◽  
Bing-Hong Wang

This paper studies the effect of vehicles' changing lanes in the original Biham–Middleton–Levine traffic flow model. According to local vehicular information, the dynamics allows for vehicles changing their rows or columns. Simulation results show that the intermediate stable phase identified in the original model can be observed and maintained in a wide range of the vehicle density in our model. Some new kinds of space configurations have been first presented and discussed. One also notes that the geometric structure of such intermediate stable phases is highly regular for square and rectangular aspect rations.


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