Two-lane System Research Articles

Pedestrian flow dynamics in a lattice gas model coupled with an evolutionary game

This paper studies unidirectional pedestrian flow by using a lattice gas model with parallel update rules. Game theory is introduced to deal with conflicts that two or three pedestrians want to move into the same site. Pedestrians are either cooperators or defectors. The cooperators are gentle and the defectors are aggressive. Moreover, pedestrians could change their strategy. The fundamental diagram and the cooperator fraction at different system width W have been investigated in detail. It is found that a two-lane system exhibits a first-order phase transition while a multilane system does not. A microscopic mechanism behind the transition has been provided. Mean-field analysis is carried out to calculate the critical density of the transition as well as the probability of games at large value of W. The spatial distribution of pedestrians is investigated, which is found to be dependent (independent) on the initial cooperator fraction when W is small (large). Finally, the influence of the evolutionary game rule has been discussed.

Influence of lane change on stability analysis for two-lane traffic flow

This paper deals mainly with the influence of lane changing behaviours on the stability of two-lane traffic flow under a periodic boundary condition. Following the description of an optimal velocity model for two vehicle groups and the derivation of their stability conditions, the feedback signals, which involve information about vehicles from both lanes acting on the two-lane traffic system, are introduced into the optimal velocity model. The control signals play a role in alleviating the traffic jam only if the traffic state is in congestion, and their role will vanish if the traffic state is in the steady state. The numerical simulations show that lane changing behaviours can break the steady state of two-lane traffic flow and aggravate the traffic disturbance, but the control method would successfully suppress the traffic jam eventually, which implies that the conclusions obtained here have certain theoretical and practical significance.

Efficacies of roadway safety improvements across functional subclasses of rural two-lane highways

Introduction Highway crash occurrence is a leading cause of unnatural deaths, and highway agencies continually seek to identify engineering measures to reduce crashes and to assess the efficacy of such measures. Most past studies on the effectiveness of roadway improvements in terms of crash reduction considered all rural two-lane sections as a single category of roads. However, it may be hypothesized that the differences in the mobility and accessibility characteristics that are reflected in (and due to) the different design standards between different functional subclasses in the rural two-lane highway system can lead to differences in efficacies of safety improvements at these subclasses. This paper investigates the efficacy of roadway improvements, in terms of crash reduction, at the various subclasses of rural two-lane highways. Methods An empirical analysis of safety performance at each of the three subclasses of rural two-lane highways was carried out using the negative binomial modeling technique. For each subclass, crash prediction models were developed separately for the three levels of crash severity: property-damage only, injury, and fatal/injury. The crash factors that were considered include lane width, shoulder width, pavement surface friction, pavement condition, and horizontal and vertical alignments. After having developed the safety performance functions, the effectiveness (in terms of the extent of crash reduction, for different levels of crash severity) of highway safety enhancements at each highway subclass were determined using the theoretical concepts established in past literature. These enhancements include widening lanes, widening shoulders, enhancing pavement surface friction, and improving the vertical or horizontal alignment. Results and Conclusion The study found that there is empirical evidence to justify the decomposition of the family of rural two-lane roads into its constituent subclasses for purposes of analyzing the effectiveness of safety enhancement projects and thus to avoid underestimation or overestimation of benefits of safety improvements at this class of highways.

Strong Asymmetric Coupling of Two Parallel Exclusion Processes

This paper studies asymmetric strong coupling effect in two parallel exclusion processes, which is a generalization of previous works of Kolomeisky group (Pronina and Kolomeisky in Physica A 372:12, 2006; Tsekouras and Kolomeisky in J. Phys. A 41:465001, 2008). It is shown that with different configurations of hopping rates, the two-lane system exhibits diverse phase diagram and density profiles. Specifically, it shows how the phase diagram changes from having seven phases, via six phases, to three phases. Moreover, it shows that the phase diagram could have only one phase, which exhibits quadrilateral or triangular density profile. The vertical cluster mean-field approach is used to get the stationary-state bulk densities and phase diagrams. Extensively Monte Carlo simulations are carried out, and theoretical predictions are in excellent agreement with simulation results.

Improved mean field analysis of spontaneous symmetry breaking in a bidirectional two-lane system with narrow entrances

This Letter presents an improved mean field analysis of a bidirectional two-lane asymmetric exclusion process with narrow entrances, which exhibits spontaneous symmetry breaking. The method takes into account the correlation of the vertical cluster at system boundaries, which shows better agreement with simulations than the simple mean field method.

Numerical study of urban traffic flow with dedicated bus lane and intermittent bus lane

Based on the cellular automaton traffic flow model and the concept of public transport priority, a two-lane traffic model with an intermittent bus lane is proposed and the properties of urban traffic flow are studied. The cases of traffic with a dedicated bus lane (DBL), an intermittent bus lane (IBL) and an ordinary two-lane traffic are simulated, and comparisons in the form of the fundamental diagrams and the velocity–density profiles are made between them. It is shown that the DBL has the advantage of freeing buses from traffic interference and also has the disadvantage of disrupting traffic, the IBL is more efficient in improving the bus flow than ordinary two-lane traffic and maintaining the car flow at a higher level at the same time than the DBL, while the ordinary two-lane traffic suppresses public transportation and is not advantageous in easing urban traffic congestion. Also it is indicated that the DBL is only appropriate for low traffic flow in a two-lane traffic system, and this limitation can be partly overcome by opening the bus lane to general traffic intermittently when the bus lane is not in use by buses.

A study on the effects of the transit parking time on traffic flow based on cellular automata theory

This paper mainly deals with the effects of transit stops on vehicle speeds and conversion lane numbers in a mixed traffic lane. Based on thorough research of traffic flow and cellular automata theory, it calibrates the cellular length and the running speed. Also, a cellular automata model for mixed traffic flow on a two-lane system under a periodic boundary condition is presented herewith, which also takes into consideration the harbour-shaped transit stop as well. By means of computer simulation, the article also studies the effects of bus parking time on the traffic volume, the transit speed and the fast lane speed at the same time. The results demonstrate that, with the increase of the bus parking time, the traffic volume of the transit stop and the transit speed decrease while the fast lane speed increases. This result could help calculate the transit delay correctly and make arrangements for transit routes reasonably and scientifically.

Pavement Rehabilitation Project Ranking Approach Using Probabilistic Long-Term Performance Indicators

A probabilistic performance-based approach for generating a priority ranking of pavement rehabilitation project candidates is presented. The deployed probabilistic approach uses a discrete-time Markovian model to predict pavement conditions at the network level. The expected future distress rating associated with a particular pavement project is determined as the mean of a compound uniform probability density function derived from the corresponding future state probabilities. The expected future distress ratings for a particular pavement project are then used to construct the corresponding performance curve. The generated performance curves form the basis for developing an effective mechanism for prioritizing potential rehabilitation projects. A priority ranking system is presented with two alternatives. The first priority ranking alternative requires a fixed analysis period wherein project candidates are evaluated by using three different long-term performance indicators derived from the corresponding performance curves. The deployed performance indicators include the area under the performance curve, the average distress rating, and the terminal distress rating. The second priority ranking alternative requires a fixed terminal distress rating for the pavement network under consideration. The time required for each project to reach the terminal distress rating is determined as the rehabilitation scheduling time, which is used to establish project priority ranking. Pavement rehabilitation project candidates are then scheduled according to their priority rankings and available budget. The developed probabilistic approach is demonstrated by considering a project sample from the two-lane highway system in Ohio.

Cellular automaton model for mixing traffic in two-lane system with period boundary condition

Based on the analysis of the existing classical cellular automaton model of traffic flow, considering the characteristic of part of expressways without differences between running lane and passing lane, we demarcated the parameters such as length of the cellar automaton, operation speed, random slow mechanism and the max speed etc, set up the vehicle's generating function and vehicle changing lane regulation, and established Cellular Automaton (CA) model for mixing traffic in two-lane system with period boundary condition. Then we analyzed the relation among three parameters of traffic flow through computer simulation, and the impact of the occupation rate of large-scale freight vehicles on traffic flow. We compared the space-time evolution figure with density changing under the same occupation of large-scale vehicles. The result shows that the occupation rate of large-scale freight vehicles has little influence on the speed of mixed traffic flow in the situation that the expressways have no differences between running ways and passing ways. The stochastic deceleration probability of the vehicle plays an important role in the motion state of mixed traffic flow.

Analysis of the influence of occupation rate of public transit vehicles on mixing traffic flow in a two-lane system

Based on the existing classical cellular automaton model of traffic flow, a cellular automaton traffic model with different-maximum-speed vehicles mixed on a single lane is proposed, in which public transit and harbour-shaped bus stops are taken into consideration. Parameters such as length of cellular automaton, operation speed and random slow mechanism are re-demarcated. A harbour-shaped bus stop is set up and the vehicle changing lane regulation is changed. Through computer simulation, the influence of occupation rate of public transit vehicles on mixed traffic flow and traffic capacity is analysed. The results show that a public transport system can ease urban traffic congestion but creates new jams at the same time, and that the influence of occupation rate of public transit vehicles on traffic capacity is considerable. To develop urban traffic, attention should be paid to the occupation rate of public transit vehicles and traffic development in a haphazard way should be strictly avoided.

Slow dynamics in a driven two-lane particle system

We study a two-lane model of two species of particles that perform biased diffusion. Extensive numerical simulations show that when bias q is strong enough, oppositely drifting particles form some clusters that block each other. Coarsening of such clusters is very slow and their size increases logarithmically in time. For smaller q, particles collapse essentially on a single cluster whose size seems to diverge at a certain value of q=qc. Simulations show that despite slow coarsening, the model has rather large power-law cooling-rate effects. It makes its dynamics different from glassy systems but similar to some three-dimensional Ising-type models (gonihedric models).

The effects of decelerating lane in the off-ramp system

In this paper,we study the effects of decelerating lane in the off-ramp system of freeway. Based on the NaSch model of traffic flow, a model of two-lane system with off-ramp is established. From the numerical simulations, we obtain the fundamental diagrams of traffic flow under different parameters. Moreover, we compare the road including decelerating lane with the road without it.

TRAFFIC DYNAMICS IN A TWO-LANE MIXED TRAFFIC SYSTEM: EFFECT OF FOUR LANE CHANGING REGULATIONS

This paper investigates traffic dynamics of two-lane mixed traffic flow system composed of cars and buses, which are characterized by different lengths and different maximum velocities. Four lane changing regulations are studied, which reveals effect of lane changing ban, symmetric and asymmetric lane changing rules on traffic flow characteristics (flow rate, carry capability, lane changing frequency, and lane usage). We expect that our results could be useful for traffic management.

Study on the traffic behavior of on-ramp system with two-lane main road under signal controlling

In this paper we investigate the two-lane main road on-ramp system with signal-controlling using the cellular automata traffic flow model. The traffic signal is setup at the merging part between the main road and the on-ramp so that it can control the vehicles of both roads. We simulate the effect of traffic signal on vehicle flows of main road and on-ramp, and the traffic capacity and average velocity at the merging part are discussed. Through the analysis of the phase diagram, it can be found that the on-ramp system with two-lane main road can embody more complicated and realistic traffic flow characteristics than the on-ramp system with single-lane main road. Compared with the model introduced by Jiang Rui ［Jiang R 2003 J. Phys. A 36 11713］, the simulation results indicate that the state of traffic flow is improved obviously and the capacity of the on ramp system has increased.

TRAFFIC BEHAVIOR IN A TWO-LANE SYSTEM CONSISTING OF A MIXTURE OF BUSES AND CARS

In this paper, a two-lane traffic system consisting of a mixture of buses and cars is studied. The buses stop at each bus stop to pick up passengers and are not allowed to change lane. The cars may change lane when hindered by preceding vehicles. Our simulations show that with a fixed number of buses, four states of the traffic system are identified. The spatial-temporal plots of the four traffic states, and the trajectories of buses at different densities are presented. A gradual transition instead of sharp phase transition from bunching state to homogeneous state of the buses is found. Next, we study the system behavior at different number of bus stops, and an optimal number of stops is suggested. Finally, the influence of bus stops on the fundamental diagram is studied.

EFFECTS OF LANGMUIR KINETICS ON TWO-LANE TOTALLY ASYMMETRIC EXCLUSION PROCESSES OF MOLECULAR MOTOR TRAFFIC

In this paper, we study a two-lane totally asymmetric simple exclusion process (TASEP) coupled with random attachment and detachment of particles (Langmuir kinetics) in both lanes under open boundary conditions. Our model can describe the directed motion of molecular motors, attachment and detachment of motors, and free inter-lane transition of motors between filaments. In this paper, we focus on some finite-size effects of the system because normally the sizes of most real systems are finite and small (e.g., size ≤ 10 000). A special finite-size effect of the two-lane system has been observed, which is that the density wall moves left first and then move towards the right with the increase of the lane-changing rate. We called it the jumping effect. We find that increasing attachment and detachment rates will weaken the jumping effect. We also confirmed that when the size of the two-lane system is large enough, the jumping effect disappears, and the two-lane system has a similar density profile to a single-lane TASEP coupled with Langmuir kinetics. Increasing lane-changing rates has little effect on density profiles after the density reaches maximum. Also, lane-changing rate has no effect on density profiles of a two-lane TASEP coupled with Langmuir kinetics at a large attachment/detachment rate and/or a large system size. Mean-field approximation is presented and it agrees with our Monte Carlo simulations.

Spontaneous symmetry breaking in a two-lane system with parallel update

This paper studies a two-lane totally asymmetric simple exclusion processes (TASEP) with narrow entrances under parallel update. Particles move on two parallel lanes in the opposite directions without lane changing. The narrow entrances are modelled in this way: the entry of a particle is not allowed if the exit site of the other lane is occupied (see also Pronina and Kolomeisky 2007 J. Phys. A: Math. Theor. 40 2275). We mainly focus on the case where particles hop deterministically in the bulk. The phase diagram, bulk density and particle currents are analysed using mean-field approximation. It is shown that there are two symmetry breaking phases, and one of them (i.e., asymmetric low density/low-density phase) occupies only a line in the phase diagram. A multi-stable phenomenon is also observed. Monte Carlo simulations are carried out and the simulation results deviate from the mean-field prediction, because correlations are not considered in mean-field calculation. A seesaw phase is reproduced when α = 1. The results are also compared with that obtained from the two-lane system with random update. Finally, preliminary simulation results where particles hop with the rate q < 1 in the bulk are reported and it is shown that the introduction of stochastic hopping changes the phase diagram structure.

The effect of restricted velocity in the two-lane on-ramp system

Usually there are multi-lane on the main road of the on-ramp system. The drivers may decelerate for more safety when they are near the on-ramp. In addition, the car velocity may be restricted according to the traffic regulation. In this paper, we study phenomenon using the cellular automata traffic flow model. We find that: (i) the phase diagram of the two-lane on-ramp system appears a new region, in which the traffic of the on-ramp reaches maximum flow. (ii) The introduction of restricted velocity region will decrease capacity of the on-ramp, but reduce the drastic velocity fluctuation near the on-ramp.

Ideal and disordered two-lane traffic models

We introduce a simple lattice-based exclusion model which can be considered as a crude representation of traffic on a two-lane motorway. The model is a two-lane generalization of the asymmetric simple exclusion process which is known to reproduce some of the features of single-lane traffic such as shocks and jams. A mean-field analysis for the steady state of the pure two-lane system is supported by Monte Carlo simulations. We then discuss the effect of quenched bond disorder on the current–density relation and draw comparisons with the disordered single-lane case.

A cellular automaton model for mixing traffic in two-lane system

Based on the Nagel-Schrekenberg(NS) model,we present a mixing traffic flow model for a two-lane traffic system. In this model,the stochastic noise P in NS model is replaced by accelerating probability Pa and braking probabil ity Pd. The fundamental diagrams of the mixing traffic under differen t conditi ons are given by the numerical simulations. We found that the lane-changing prob ability,the mixing rate and acceleration, the braking probability have a great i nfluence on the mixing traffic flow. The slow cars have a decisive action on the mixing traffic.