Two-lane Model Research Articles

Two-lane mixed traffic flow model considering lane changing

Based on the analysis of the advantages and disadvantages of the existing car-following model and combined with the actual road conditions, an improvement scheme is proposed for the selected model. The improvement plan adds the consideration of the speed difference between the front and rear vehicles, and introduces the safe distance parameter of the most dangerous situation when the vehicle is braking. The comparison with the actual measurement results after simulation and conversion shows that the improved car following model is effective and the vehicle lane change rules are improved. The improvement of lane changing rules allows different lane changing rules to be obtained in different situations. The lane-changing rules are coupled with the improved car-following model to obtain a two-lane model based on different rules. The corresponding programming simulation is compared with the measured road results to verify the practicability of the model. The simulation result shows that the new model can still reproduce the road traffic flow under different lane changing rules. After the introduction of mixed traffic, the model can reproduce the maximum flow of the road within the error tolerance.

Two-lane totally asymmetric simple exclusion process with extended Langmuir kinetics.

Multilane totally asymmetric simple exclusion processes with interactions between the lanes have recently been investigated actively. This paper proposes a two-lane model with extended Langmuir kinetics on a periodic lattice. Both bidirectional and unidirectional flows are investigated. In our model, the hopping, attachment, and detachment rates vary depending on the state of the corresponding site in the other lane. We obtain a theoretical expression for the global density of the system in the steady state from three kinds of mean-field analyses [(1×1)-, (2×1)-, and (2×2)-cluster cases]. We verify that the (2×2)-cluster mean-field analysis reproduces the differences between the two directional flows and approximates well the results of computer simulations for some cases. We observe that (2×1)-cluster mean-field analyses are already good approximations of the simulation results for unidirectional flows; on the other hand, the accuracy of the approximations much improves by (2×2)-cluster one for bidirectional flows. We explain the phenomena in a qualitative manner by a simple analysis of correlations. We expect these findings to give informative suggestions for actual traffic systems.

Theoretical analysis and simulation of phase separation in a driven bidirectional two-lane system.

The two-lane driven system is a type of important model to research some transport systems, and also a powerful tool to investigate properties of nonequilibrium state systems. This paper presents a driven bidirectional two-lane model. The dynamic characteristics of the model with periodic boundary are investigated by Monte Carlo simulation, simple mean field, and cluster mean field methods, respectively. By simulations, phase separations are observed in the system with some values of model parameters. When the phase separation does not occur, cluster mean field results are in good agreement with simulation results. According to the cluster mean field analysis and simulations, a conjecture about the condition that the phase separation happens is proposed. Based on the conjecture, the phase boundary distinguishing phase separation state and homogeneous state is determined, and a corresponding phase diagram is drawn. The conjecture is validated through observing directly the spatiotemporal diagram and investigating the coarsening process of the system by simulation, and a possible mechanism causing the phase separation is also discussed. These outcomes maybe contribute to understand deeply transport systems including the congestion and efficiency of the transport, and enrich explorations of nonequilibrium state systems.

Two-lane lattice hydrodynamic model considering the empirical lane-changing rate

As a common behavior, lane changing has a significant influence on traffic flow. Lane changing is heavily dependent on the surrounding environment, so having a constant lane-changing rate in a traffic flow model would be unreasonable. Through an analysis of three empirical lane-changing datasets, we find that the lane-changing rate depends on traffic density. The structure of the lane-changing rate is similar to an optimization velocity function. We propose a new two-lane lattice model by modifying the lane-changing rate in the conservation equation. The linear stability of the new model and the effects of the parameters in the lane-changing rate on linear stability are analyzed through theory and simulation. Moreover, the new model and Nagatani's two-lane model are compared with actual observation results, which shows that the new model can better reproduce the observation results.

Modeling Mixed Bicycle Traffic Flow: A Comparative Study on the Cellular Automata Approach

Simulation, as a powerful tool for evaluating transportation systems, has been widely used in transportation planning, management, and operations. Most of the simulation models are focused on motorized vehicles, and the modeling of nonmotorized vehicles is ignored. The cellular automata (CA) model is a very important simulation approach and is widely used for motorized vehicle traffic. The Nagel-Schreckenberg (NS) CA model and the multivalue CA (M-CA) model are two categories of CA model that have been used in previous studies on bicycle traffic flow. This paper improves on these two CA models and also compares their characteristics. It introduces a two-lane NS CA model and M-CA model for both regular bicycles (RBs) and electric bicycles (EBs). In the research for this paper, many cases, featuring different values for the slowing down probability, lane-changing probability, and proportion of EBs, were simulated, while the fundamental diagrams and capacities of the proposed models were analyzed and compared between the two models. Field data were collected for the evaluation of the two models. The results show that the M-CA model exhibits more stable performance than the two-lane NS model and provides results that are closer to real bicycle traffic.

Correlation analysis of synchronization flow at a traffic bottleneck

In this paper, we study the correlation characteristics of synchronization flow in a two-lane model with the partial reduced lane based on the Kerner–Klenov–Wolf cellular automation model using the detrended fluctuation analysis (DFA). The local fundamental diagram and cross-correlation near the entry of the partial reduced lane have been analyzed in the periodic boundary condition. The typical two-dimensional scatter diagram in the local fundamental diagram and the noncorrelation of the cross-correlation between the local density and flow reveal characteristics of synchronization flow near the entry of the reduced lane. By the DFA, the synchronized flow at a traffic bottleneck exhibits the characteristics of long-range correlation. The results of investigation indicate that the injection rate, removal rate, and the location of the partial reduced lane have an obvious influence on the change of the scale exponent in the open boundary condition. Moreover, the length of the partial reduced lane has impact on the change of the scale exponent in the periodic boundary condition.

The velocity difference control signal for two-lane car-following model

Based on single-lane traffic model, a two-lane traffic model is presented considering the velocity difference control signal. The stability condition of the model is obtained by the control theory. The delayed feedback control signal is added to the two-lane model, and the corresponding stability condition is derived again. The numerical simulations show that as the stability conditions are satisfied, the small disturbance will not amplify with and without control signal. In the meantime, the stability is strengthened as the control signal is considered. So the control signal would suppress the traffic disturbance successfully.

The Application of Cellular Automata in Traffic Flow Management and the Present Situation

Review the research process and results of cellular automaton used for traffic flow, and against the theory based on cellular automata model established lane, two-lane model, multi-lane traffic network model and discuss the model. Then introduced the research status and development trends of various models. Finally, prospect the future of the cellular automata used to traffic flow managements development trend and research direction, and provide a reference for building traffic management mode suit to the characteristics of the transportation.

Anomalous coarsening in disordered exclusion processes

We study coarsening phenomena in three different simple exclusion processes with quenched disordered jump rates. For a totally asymmetric process, an earlier phenomenological description is improved, yielding ξ(t) ∼ t/(lnt)2 for the time dependence of the length scale, which is found to be in agreement with results of Monte Carlo simulations. For a partially asymmetric process, the logarithmically slow coarsening predicted by a phenomenological theory is confirmed by Monte Carlo simulations and numerical mean-field calculations. Finally, coarsening in a bidirectional, two-lane model with random lane-change rates is studied. Here, Monte Carlo simulations indicate an unusual dependence of the dynamical exponent on the density of particles.

Spontaneous symmetry breaking in a two-lane model for bidirectional overtakingtraffic

Firstly, we consider a unidirectional flux of vehicles, each of which is characterized by its ‘natural’ velocityv drawn from adistribution P(v). The traffic flow is modeled as a collection of straight ‘world lines’ in thetime–space plane, with overtaking events represented by a fixed queuing timeτ imposed on the overtaking vehicle. This geometrical model exhibits platoon formation andallows, among many other things, for the calculation of the effective average velocity of a vehicle of natural velocityv. Secondly, we extend the model to two opposite lanes, A and B. We argue that the queuing timeτ in one lane is determined by the traffic density in the opposite lane. On the basis ofreasonable additional assumptions we establish a set of equations that couple the two lanesand can be solved numerically. It appears that above a critical value of the control parameter the symmetry between the lanes is spontaneously broken: there is a slow lane where longplatoons form behind the slowest vehicles, and a fast lane where overtaking iseasy due to the wide spacing between the platoons in the opposite direction. Avariant of the model is studied in which the spatial vehicle density rather than the flux is the control parameter. Unequal fluxes and in the two lanes are also considered. The symmetry breaking phenomenon exhibited bythis model, even though no doubt hard to observe in pure form in real-life traffic,nevertheless indicates a tendency of such traffic.

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).

Traffic mixing in deterministic two-lane model of Hurricane evacuation

We study the mixing of vehicles on a two-lane highway in Hurricane evacuation. We present the deterministic model of two-lane traffic in which vehicles change the lane by a deterministic rule. We investigate the typical traffic induced by a slow vehicle on the first lane under the open boundary. The escape time of vehicles is determined by their order. The vehicular order changes by traffic mixing. The traffic mixing depends highly on the sensitivity. For high sensitivity, the escape time depends on the initial order of vehicles. For low sensitivity, the lane changing occurs irregularly by stop- and go-waves and vehicles then evacuate irregularly without keeping their initial order.

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

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.

Synchronization of kinks in the two-lane totally asymmetric simple exclusion process with open boundary conditions

We study the motion of kinks in a two-lane model of the totally asymmetric simple exclusion process with open boundaries. We analytically study the motion of the kinks by a decoupling approximation. In terms of the decoupling approximation, we find that the positions of the kinks become synchronized, though the difference in the number of particles between lanes remains non-zero when the rate of lane change is asymmetric. The validity of this result is confirmed for small asymmetric cases through the Monte Carlo simulation.

Honk effect in the two-lane cellular automaton model for traffic flow

In real traffic, when a vehicle is hindered by its preceding vehicle and simultaneously it cannot change lane, it may honk the horn. As a result, the driver of the preceding vehicle may change lane to make way for it. However, this effect has seldom been investigated before. In this paper, we take this issue into account by proposing a new symmetric two-lane cellular automaton model. It is shown that the honk has almost no effect in the homogeneous traffic whereas it enhances the flux in the intermediate density regime for the heterogeneous traffic. We suggest that this is because the occurrence probability and the lifetime of the plug are suppressed due to the introduction of the honk. Finally, we argue that the honk behavior is not encouraged in the asymmetric two-lane model.

TWO-LANE TRAFFIC WITH PLACES OF OBSTRUCTION TO TRAFFIC

As the Nagel–Schreckenberg model (NaSch model) became known as a realistic approach to describe traffic flow on single-lane streets, this model was extended to two-lane traffic by several groups. On the base of our two-lane model, we will now investigate the impact of a place of obstruction, e.g., because of road works, on partial fractions, densities and mean velocities.