Effect of Multi-Slowdown Sections on Traffic Flow

2012 ◽  
Vol 253-255 ◽  
pp. 1619-1622
Author(s):  
Yan Hong Fan ◽  
Hua Kuang ◽  
Guo Xin Zhang ◽  
Ling Jiang Kong ◽  
Xing Li Li
Keyword(s):  
Energy Consumption ◽  
Traffic Flow ◽  
Maximum Flow ◽  
Underlying Mechanism ◽  
Speed Limit ◽  
Fundamental Diagram ◽  
Mean Velocity ◽  
Traffic System ◽  
Flow Phase ◽  
Multi Phase

Based on the NS model, an extended cellular automaton model is proposed to simulate complex characteristics and energy consumption of traffic flow with some slowdown sections on a highway by considering the number, speed limit and distribution of slowdown sections. The simulation results show that the present model can exhibit a multi-phase coexistence phenomenon, i.e., the freely moving phase, the maximum flow phase and the jamming phase coexist in traffic system. The fundamental diagram shows that the number of slowdown section has no influence on the mean velocity and flow. However, energy consumption increases with increase of the number of slowdown section at low density. In addition, it can be found that the speed limit and distribution of different slowdown sections have an important effect on traffic flow and energy consumption, and the underlying mechanism is also analyzed.

Traffic accidents on a single-lane road with multi-slowdown sections

2014 ◽  
Vol 25 (09) ◽  
pp. 1450036 ◽  
Author(s):  
Xingli Li ◽  
Hua Kuang ◽  
Yanhong Fan ◽  
Guoxin Zhang
Keyword(s):  
Traffic Congestion ◽  
Traffic Accidents ◽  
Underlying Mechanism ◽  
Mean Flow ◽  
Fundamental Diagram ◽  
Mean Velocity ◽  
Car Accidents ◽  
Flow Phase ◽  
Normal Speed ◽  
The Mean

In this paper, an extended cellular automaton model is proposed to simulate the complex characteristics of traffic flow and the probability of the occurrence of traffic accidents by considering the modified conditions for determining whether traffic accidents happen and the effect of multi-slowdown sections on a highway. The simulation results show that the multi-slowdown sections can lead to multiphase coexistences (i.e. free flow phase, congestion phase and saturation phase) in traffic system. The fundamental diagram shows that the number of slowdown section does not influence the mean velocity and the mean flow under the periodic boundary condition, but the existence of slowdown sections can effectively reduce the occurrence of traffic accident. In particular, it is found that the probability of car accidents to occur is the largest at the joint of the normal-speed section and slowdown section, and the underlying mechanism is analyzed. In addition, to design the appropriate limited speed and reduce the differences between the normal speed and limited speed will alleviate traffic congestion and reduce the occurrence of traffic accidents obviously.

A new cellular automata traffic flow model considering asynchronous update of vehicle velocity

2020 ◽  
Vol 31 (12) ◽  
pp. 2050167
Author(s):  
Qi-Lang Li ◽  
Rui Jiang ◽  
Zhong-Jun Ding ◽  
Bing-Hong Wang
Keyword(s):  
Cellular Automata ◽  
Traffic Flow ◽  
Flow Model ◽  
Maximum Flow ◽  
Fundamental Diagram ◽  
Time Step ◽  
Traffic Flow Model ◽  
Traffic Jam ◽  
Vehicle Velocity ◽  
Flow Phase

This study examines the cellular automata traffic flow model, which considers the asynchronous update of vehicles’ velocities. Computer simulations are used to identify three typical phases: linear free flow phase, nonlinear moving phase and traffic jam phase. Compared to the original NaSch model, the system of the present model can reach the maximum flow when the vehicle density is higher. The influence of the delay probability and the maximum time step in which drivers intend to keep their current velocity on fundamental diagram is discussed.

A NEW CELLULAR AUTOMATON MODEL FOR TRAFFIC FLOW WITH DIFFERENT PROBABILITY FOR DRIVERS

2007 ◽  
Vol 18 (05) ◽  
pp. 773-782 ◽  
Author(s):  
H. B. ZHU ◽  
H. X. GE ◽  
S. Q. DAI
Keyword(s):  
Cellular Automaton ◽  
Traffic Flow ◽  
Metastable State ◽  
Maximum Flow ◽  
Traffic Model ◽  
Fundamental Diagram ◽  
Density Dependent ◽  
Spontaneous Formation ◽  
Traffic Jams ◽  
Ca Model

Based on the Nagel–Schreckenberg (NaSch) model of traffic flow, a new cellular automaton (CA) traffic model is proposed to simulate microscopic traffic flow. The probability p is a variable which contains a randomly selected term for each individual driver and a density-dependent term which is the same for all drivers. When the rational probability p is obtained, the larger value of maximum flow which is close to the observed data can be reached compared with that obtained from the NaSch model. The fundamental diagram obtained by simulation shows the ability of this modified CA model to capture the essential features of traffic flow, e.g., the spontaneous formation of traffic jams and appearance of the metastable state. These indicate that the presented model is more reasonable and realistic.

OPTIMIZATION OF TRAFFIC LIGHTS AT CROSSROADS

2003 ◽  
Vol 14 (05) ◽  
pp. 539-548 ◽  
Author(s):  
DING-WEI HUANG ◽  
WEI-NENG HUANG
Keyword(s):  
Traffic Flow ◽  
Probabilistic Models ◽  
Urban Traffic ◽  
Speed Limit ◽  
Stochastic Noise ◽  
Traffic Light ◽  
Fundamental Diagram ◽  
Traffic Lights ◽  
Signal Period ◽  
Two Parameters

We study the influence of traffic lights on the traffic flow in cities. The urban traffic is simulated in the cellular automata framework. Both the deterministic and probabilistic models are discussed. The effects of speed limit and stochastic noise are analyzed. The operation of a traffic light is characterized by two parameters: signal period and phase allocation. With two traffic lights on road, one more parameter is prescribed: synchronization shift. The results of tuning these parameters are presented in the fundamental diagram. We examine the traffic flow and discuss the choice of optimized setting in different density regions.

scholarly journals Impact of Road Bends on Traffic Flow in a Single-Lane Traffic System

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zeng Junwei ◽  
Qian Yongsheng ◽  
Xu Dejie ◽  
Jia Zhilong ◽  
Huang Zhidan
Keyword(s):  
Traffic Flow ◽  
Peak Flow ◽  
Inhibitory Effect ◽  
Arc Length ◽  
Traffic Flows ◽  
Bend Radius ◽  
Fundamental Diagram ◽  
Traffic System ◽  
Inhibition Effect ◽  
Road Friction

Taking the characteristics of road bends as a research object, this work proposes the cellular model (CA) with road bends based on the NaSch model, with which the traffic flow is examined under different conditions, such as bend radius, bend arc length, and road friction coefficiency. The simulation results show that, with the increase of the bend radius, the peak flow will be continuously increased, and the fundamental diagram will become more similar to that of the classic NaSch model; the smaller the bend radius is, the easier it is for the occurrence of blockage; for different bend lengths, all the corresponding traffic flows show that the phenomenon of go-and-stop and the bends exert slight inhibitory effect on traffic flow; under the same bend radius, the inhibition effect of the bends on the traffic flow will be weakened with the increase of the friction coefficiency.

scholarly journals Statistical forecasting of high-way traffic jam at a bottleneck

2012 ◽  
Vol 9 (1) ◽  
Author(s):  
Igor Grabec ◽  
Franc Švegl
Keyword(s):  
Mathematical Model ◽  
Traffic Flow ◽  
Continuity Equation ◽  
Numerical Treatment ◽  
Input Flow ◽  
Fundamental Diagram ◽  
Mean Velocity ◽  
Traffic Jam ◽  
The Mean ◽  
Bottleneck Capacity

Maintenance works on high-ways usually require installation of bottlenecks that disturb traffic. The article presents a new mathematical model for analysis and forecasting of traffic jam evolution in front of a bottleneck. The model is comprised of two partial differential equations for the mean velocity and density of cars. The first equation describes relaxation of velocity to its equilibrium value determined by a new fundamental diagram. The second is the continuity equation and describes adaptation of the density to the input traffic flow that is forecast statistically. Numerical treatment of the model yields distributions of traffic variables that exhibit characteristic properties of jam evolution. The performance of the method is demonstrated by forecasting the jam that would develop during rush-hour if a bottleneck were installed on a high-way close to Ljubljana. Beside the model a new method is presented for approximate prediction of jam length based upon input flow and bottleneck capacity that is specified by the fundamental diagram. The corresponding computer programs represent a new tool by which experts can analyze properties of bottlenecks in order to optimize them.

Energy Consumption in Traffic Flow with a Slowdown Section

2012 ◽  
Vol 524-527 ◽  
pp. 3093-3096 ◽  
Author(s):  
Yan Hong Fan ◽  
Hua Kuang ◽  
Guo Xin Zhang ◽  
Ling Jiang Kong
Keyword(s):  
Energy Consumption ◽  
Traffic Flow ◽  
Traffic Control ◽  
Speed Limit ◽  
Stochastic Noise ◽  
Important Conclusion ◽  
Vehicle Accidents ◽  
Energy Consumption Analysis ◽  
Reduce Energy Consumption ◽  
Simulation Results

Based on the Nagel-Schreckenberg model, an extended cellular automaton model is proposed to simulate the characteristics of the energy consumption in traffic flow with a slowdown section by considering the stochastic noise, the length and speed limit of the slowdown section. The simulation results show that the energy consumption is determined by the length Ls of the slowdown section as well as the speed limit Vs of the slowdown section. The smaller Vs and the larger Ls can effectively alleviate energy consumption. Through vehicle accidents and energy consumption analysis, an important conclusion is drawn that Vs =1 may be an optimum design to drive safely and reduce energy consumption from traffic control. Furthermore, the stochastic braking probability P has also an important effect on energy consumption.

scholarly journals Traffic flow rate on Kigali roads: a case of national roads (RN1 and RN3)

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Jacqueline Nyirajana ◽  
Akinwale Oladotun Coker ◽  
Folake Olubunmi Akintayo
Keyword(s):  
Traffic Flow ◽  
Flow Rate ◽  
Critical Density ◽  
Maximum Flow ◽  
Carbon Dioxide Production ◽  
Flow State ◽  
Fundamental Diagram ◽  
Essential Facility ◽  
Time Scheduling ◽  
Road Planning

Traffic flow study plays a key important in various functionalities of cities all over the world. The study of traffic flow is also viewed as an essential facility of the country when it wants to establish traffic operations patterns in the progress of road planning. Blockages are accountable for a sequence of harmful effects such as loss of time, scheduling difficulties, carbon dioxide production, and risks of accidents as well as external expenses. Besides, inadequate transportation facilities and increased traffic volume hamper urban development, especially in developing nations. The objective of the study was to assess the traffic flow state in two selected national roads of Kigali city. The traffic data were collected from 5 am to 8 pm on two National Roads (RN1 and RN3).  The relationship between density and flow rate was analyzed using the fundamental diagram of traffic flow. It was found that the peak hours were from 6 am to 8 am and 5 pm to 8 pm. The highest number of vehicles counted were motorcycles due to shortcuts taken to reduce travel time. The results on RN3 revealed a proportion increase of traffic flow and density in the free-flow regime from 0 to maximum flow of 3346.6 veh/h correspondent to a critical density of 114.9 veh/km. However, in the congested zone regime, there was a decrease in traffic flow and an increase in density. It was found that the curve of flow versus density tended to increase on-road RN1. This study proposed the promotion of public transport and e-commerce as strategies to mitigate the congestion. Also, further research may be carried out on all roads of Kigali city, to provide the level of congestion useful for traffic deviation accordingly.

Field Theory for Some Traffic Phenomena and Fundamental Diagram

2021 ◽  
pp. 036119812110064
Author(s):  
Daiheng Ni
Keyword(s):  
Field Theory ◽  
Traffic Flow ◽  
Causal Effect ◽  
Microscopic Approach ◽  
Fundamental Diagram ◽  
Longitudinal Control ◽  
Effect Analysis ◽  
Vehicle Trajectories ◽  
Vehicle Motion ◽  
Cross Reference

A fundamental diagram consists of a scatter of traffic flow data sampled at a specific location and aggregated from vehicle trajectories. These trajectories, if presented equivalently, constitute a microscopic version of the (conventional) fundamental diagram. The cross-reference between vehicle trajectories and the microscopic fundamental diagram provides details of vehicle motion dynamics which allow causal-effect analysis on some traffic phenomena and further reveal the microscopic basis of the conventional fundamental diagram. This observation inspires theoretical modeling by a microscopic approach to address traffic phenomena and the conventional fundamental diagram. Derived from the field theory of traffic flow, the longitudinal control model is capable of serving the purpose without the modifications or exceptions used by other approaches.

scholarly journals Exploring the Distribution of Traffic Flow for Shared Human and Autonomous Vehicle Roads

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3425
Author(s):  
Huanping Li ◽  
Jian Wang ◽  
Guopeng Bai ◽  
Xiaowei Hu
Keyword(s):  
Traffic Flow ◽  
Autonomous Vehicles ◽  
Flow Model ◽  
Road Traffic ◽  
Autonomous Vehicle ◽  
Transformation Model ◽  
Hydrodynamic Theory ◽  
Traffic Flow Model ◽  
Traffic System ◽  
The Stability

In order to explore the changes that autonomous vehicles would bring to the current traffic system, we analyze the car-following behavior of different traffic scenarios based on an anti-collision theory and establish a traffic flow model with an arbitrary proportion (p) of autonomous vehicles. Using calculus and difference methods, a speed transformation model is established which could make the autonomous/human-driven vehicles maintain synchronized speed changes. Based on multi-hydrodynamic theory, a mixed traffic flow model capable of numerical calculation is established to predict the changes in traffic flow under different proportions of autonomous vehicles, then obtain the redistribution characteristics of traffic flow. Results show that the reaction time of autonomous vehicles has a decisive influence on traffic capacity; the q-k curve for mixed human/autonomous traffic remains in the region between the q-k curves for 100% human and 100% autonomous traffic; the participation of autonomous vehicles won’t bring essential changes to road traffic parameters; the speed-following transformation model minimizes the safety distance and provides a reference for the bottom program design of autonomous vehicles. In general, the research could not only optimize the stability of transportation system operation but also save road resources.

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