scholarly journals A Division Method of Determining the Early-Warning Zone on an Expressway for Automated Vehicles

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jiawen Wang ◽  
Shaobo Li ◽  
Yining Lu ◽  
Lubang Wang
Keyword(s):  
Cellular Automaton ◽  
Early Warning ◽  
Cellular Automaton Model ◽  
Mixed Traffic ◽  
Automated Vehicles ◽  
Automated Driving ◽  
Traffic Incidents ◽  
Lane Changing ◽  
Automatic Driving ◽  
Urban Expressway

Using a cellular automaton model, this paper studied the evolution mechanism of traffic incidents affecting the capacity of urban expressway under the mixed traffic environment of manual driving and automatic driving. It showed that the length of the automated-driving early-warning zone could affect the capacity of expressway. Specifically, the early-warning zone is divided into an accelerate lane-changing area, a decelerate lane-changing area, and a forced lane-changing area. The areas vary according to the distance between the vehicle and the location of incident. Based on the study, this paper establishes a codirectional two-lane cellular automaton model. The analysis showed that the capacity of the urban expressway varies under different combinations of early-warning area length and division ratio of early-warning zone. In the case of two-lane reduction caused by traffic incidents, the capacity of the expressway is optimized when the length of early-warning zone is between 450 and 600 m, and the ratio of accelerate zone, decelerate zone, and forced zone to the length of early-warning zone is, respectively, 75%, 10%, and 15%. In addition, this study showed that the capacity will rise with the increase in automated vehicles.

scholarly journals Modeling urban expressway systems with ramps and accessory roads by cellular automaton model

2009 ◽  
Vol 58 (5) ◽  
pp. 3014
Author(s):  
Mei Chao-Qun ◽  
Huang Hai-Jun ◽  
Tang Tie-Qiao
Keyword(s):  
Cellular Automaton ◽  
Cellular Automaton Model ◽  
Urban Expressway

scholarly journals Will Automated Vehicles Negatively Impact Traffic Flow?

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
S. C. Calvert ◽  
W. J. Schakel ◽  
J. W. C. van Lint
Keyword(s):  
Traffic Flow ◽  
Gradual Transition ◽  
Mixed Traffic ◽  
Limited Data ◽  
Automated Vehicles ◽  
Automated Driving ◽  
Low Level ◽  
Negative Effect ◽  
Vehicle Automation ◽  
Capacity Drop

With low-level vehicle automation already available, there is a necessity to estimate its effects on traffic flow, especially if these could be negative. A long gradual transition will occur from manual driving to automated driving, in which many yet unknown traffic flow dynamics will be present. These effects have the potential to increasingly aid or cripple current road networks. In this contribution, we investigate these effects using an empirically calibrated and validated simulation experiment, backed up with findings from literature. We found that low-level automated vehicles in mixed traffic will initially have a small negative effect on traffic flow and road capacities. The experiment further showed that any improvement in traffic flow will only be seen at penetration rates above 70%. Also, the capacity drop appeared to be slightly higher with the presence of low-level automated vehicles. The experiment further investigated the effect of bottleneck severity and truck shares on traffic flow. Improvements to current traffic models are recommended and should include a greater detail and understanding of driver-vehicle interaction, both in conventional and in mixed traffic flow. Further research into behavioural shifts in driving is also recommended due to limited data and knowledge of these dynamics.

A REALISTIC TWO-LANE CELLULAR AUTOMATON MODEL FOR TRAFFIC FLOW

2004 ◽  
Vol 15 (03) ◽  
pp. 381-392 ◽  
Author(s):  
BIN JIA ◽  
RUI JIANG ◽  
QING-SONG WU
Keyword(s):  
Cellular Automaton ◽  
Homogeneous System ◽  
Cellular Automaton Model ◽  
Inhomogeneous System ◽  
Qualitative Properties ◽  
Fundamental Diagram ◽  
Lane Changing ◽  
Traffic System ◽  
Velocity Effect ◽  
Honk Effect

This paper extends a recently proposed single-lane cellular automaton model [Li et al., Phys. Rev. E64, 066128 (2001)], which considers the velocity effect of the preceding car, to two-lane traffic system. The traffic behaviors in both homogeneous system and inhomogeneous system are investigated. For homogeneous traffic, it is shown that the velocity effect enhances the maximum flux but does not change the qualitative properties of the fundamental diagram. Nevertheless, the qualitative changes of the lane changing frequency and congested pattern occur. In the inhomogeneous system, the honk effect is studied. It is found that the honk effect first strengthens then weakens with the increase of R, the ratio of slow cars to all cars.

COMBINED CELLULAR AUTOMATON MODEL FOR MIXED TRAFFIC FLOW WITH NON-MOTORIZED VEHICLES

2010 ◽  
Vol 21 (12) ◽  
pp. 1443-1455 ◽  
Author(s):  
DONG-FAN XIE ◽  
ZI-YOU GAO ◽  
XIAO-MEI ZHAO
Keyword(s):  
Cellular Automaton ◽  
Flux Density ◽  
Traffic Flow ◽  
Critical Density ◽  
Cellular Automaton Model ◽  
Mixed Traffic ◽  
Density Region ◽  
Mixed Traffic Flow ◽  
Maximum Flux ◽  
Large Density

To depict the mixed traffic flow consisting of motorized (m-) and non-motorized (nm-) vehicles, a new cellular automaton model is proposed by combining the NaSch model and the BCA model, and some rules are also introduced to depict the interaction between m-vehicles and nm-vehicles. By numerical simulations, the flux-density relations are investigated in detail. It can be found that the flux-density curves of m-vehicle flow can be classified into two types, corresponding to small and large density regions of nm-vehicles, respectively. In small density region of nm-vehicles, the maximum flux as well as the critical density decreases with the increase of nm-vehicle density. Similar characteristics can also be found in large density region of nm-vehicles. However, compared with the former case, the maximum flux is much lower, the phase transition from free flow to congested flow becomes continuous and thus the corresponding critical points are non-existent. The flux-density curves of nm-vehicle flow can also be classified into two types. And interestingly, the maximum flux and the corresponding density decrease first and keep constant later as the density of m-vehicle increases. Finally, the total transport capacity of the system is investigated. The results show that the maximum capacity can be reached at appropriate proportions for m-vehicles and nm-vehicles, which induces a controlling method to promote the capacity of mixed traffic flow.

SYNCHRONIZED FLOW AND PHASE SEPARATION IN A TWO-LANE CELLULAR AUTOMATON MODEL

2007 ◽  
Vol 18 (02) ◽  
pp. 267-279 ◽  
Author(s):  
YAO-MING YUAN ◽  
RUI JIANG ◽  
QING-SONG WU ◽  
RUILI WANG
Keyword(s):  
Phase Separation ◽  
Cellular Automaton ◽  
Cellular Automaton Model ◽  
The Other ◽  
Free Flow ◽  
Density Range ◽  
Fundamental Diagram ◽  
Empirical Observation ◽  
Lane Changing ◽  
Rule Set

This paper extends a cellular automaton model, named modified comfortable driving (MCD) model, to a two-lane roadway. A symmetric lane-changing rule set has been proposed (Set I). The fundamental diagram, the lane-changing frequency and space-time plots are presented. It is found that for the two-lane model, there exists a density range in which phase separation between synchronized flow and wide-moving jams on one lane, and between light synchronized flow and heavy synchronized flow on the other lane, can be maintained for quite long periods of time. In this density range, (i) the outflow from jams is synchronized flow; (ii) wide moving jams are sparse. These are consistent with the empirical observation. We also investigate a slightly different lane-changing rule Set II in which stopped vehicles are not allowed to change lane. It is shown that in this case, the phase separation, between free flow and wide moving jams on one lane and between free flow and heavy synchronized flow on the other lane, can be maintained for sufficiently long periods of time. Consequently, the flux is enhanced comparing to that of rule Set I.

Study on Simulation Model of the Cellular Automaton for Passive Lane-Changing Based on the Avoidance of the Prospective Following Vehicle

2011 ◽  
Vol 268-270 ◽  
pp. 1627-1632
Author(s):  
Jing Bian ◽  
Hong Zhuang ◽  
Wei Li
Keyword(s):  
Simulation Model ◽  
Cellular Automaton ◽  
Traffic Flow ◽  
Traffic Simulation ◽  
Hybrid Vehicles ◽  
Cellular Automaton Model ◽  
Lane Changing ◽  
Cellular Automation ◽  
Simulation Results ◽  
Cellular Automation Model

It is the key fact for the accuracy of traffic simulation that the cellular automation model of traffic flow could simulate the real hybrid traffic flow. This article shows the method to improve cellular automaton model about two-lane hybrid vehicles based on passive lane-changing, to propose the avoidance rules about the prospective following vehicle, and to suggest the cellular automaton model and evolution rules based on the prospective following vehicle’s avoider. The simulation results show that the erroneous judgment rate for changing lane is the important facts for the state of two-lane hybrid traffic flow, and the accuracy of the simulation is improved in this article.

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