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A modified optimal velocity with dynamical safety headway is introduced based on the optimal velocity car-following model. The dynamical safety headway relates to vehicle's velocity compared to the constant safety headway. To study the influence of dynamical safety headway on the car-following performance, theoretical analysis and numerical simulation of the optimal velocity car-following model with dynamical safety headway are carried out. With the stability analysis method in control theory, a linear stability condition is obtained for the new model. In addition, the car-following performances of traffic flow evolution rules, traffic capacity properties and vehicle starting features of the new model are exhibited through numerical simulation. The results show that the dynamical safety headway is more efficient than the constant safety headway in improving traffic stability, enhancing traffic capacity and shortening the vehicle starting time in the car-following process. It concludes that the dynamical safety headway is a better strategy compared to constant safety headway in real car-following control. [ABSTRACT FROM AUTHOR]

• A double flow controlled discrete-time two-lane traffic system with vehicle-to-infrastructure communication is proposed. • A stable condition of the traffic system is derived with lyapunov stability theorem and given by linear matrix inequality. • The double flow control scheme can suppress traffic congestion efficiently. • The relative flow is more effective than the delayed flow in stabilizing traffic flow. • The control scheme can lower energy consumption of the traffic system. Through vehicle-to-infrastructure communication, the road-side units could collect traffic information of a selected road section and send the refined traffic information to the vehicles on the road after information processing with edge computing servers. To study the impact of traffic information in different road sections on traffic flow, a double flow controlled two-lane traffic system considering vehicle-to-infrastructure communication is introduced in this paper. The new traffic system is analyzed with Lyapunov stability theorem and a sufficient stable condition is provided in linear matrix inequality. Through simulation, the traffic flow evolution properties and energy consumption rules under different control gains and lane changing parameters are exhibited. The results show that traffic congestion and energy consumption of the two-lane traffic system can be suppressed by taking the delayed flow control information, the relative flow control information, and lane changing effect into account. Also, the role of the control strategy on traffic flow is revealed microscopically through a two-lane car-following model by transforming the macroscopic traffic flow to vehicle's velocity. It further proved the stabilization effect of the control information on traffic flow. This research can provide some theoretical guidance for traffic control through vehicle-to-infrastructure information interaction. [ABSTRACT FROM AUTHOR]

Under the condition of vehicle-to-vehicle communication, different information transmission mechanisms may have different effects on the cooperative performance of road traffic. In this paper, a new car-following model with consideration of the iterative traffic information transmission mechanism of vehicle-to-vehicle communication is proposed. The influence of the iterative traffic information transmission mechanism on the cooperative car-following behavior has been revealed. It is proved that based on the iterative traffic information transmission of vehicle-to-vehicle communication, the information of the two nearest preceding vehicles ahead of the ego vehicle has the most obvious role in stabilizing traffic flow. Also, the information of the third or fourth vehicles in front of the ego vehicle has a certain stabilizing effect, but the traffic information of the fifth or further preceding vehicles in front of the ego vehicle has little effect in enhancing traffic stability. This result provides a reference vehicle number for the cooperative car-following performance under the iterative traffic information transmission mechanism of vehicle-to-vehicle communication. [ABSTRACT FROM AUTHOR]

A smart grid uses automation and information communication technologies to guarantee its integrity. The first step of smart grid construction is the deployment of an advanced metering infrastructure system, which can read meter data automatically and maximize energy efficiency. Messages are collected at hubs distributed throughout the smart grid and sent through limited network resources. The advanced metering infrastructure system comprises a meter data management system, concentrators, relay stations between a set of smart meters and the control center, and smart meters that can collect the information of thousands of users. Concerns regarding this system are the loading on the control center, the volume of data traffic, and the quantity of the data. This study analyzes various situations of data traffic, uses Poisson process, and proposed two schemes to reduce the transmission frequency and the total data volume. A concentrator is determined to reduce the transmission frequency and compress the data from smart meters to the control center, thereby reducing the total data volume. Furthermore, the proposed scheme can reduce the loading on the control center. [ABSTRACT FROM AUTHOR]

This paper put forward a new discrete-time lattice hydrodynamic model with a steady flow control strategy. The controlled discrete-time lattice hydrodynamic model is theoretically studied by the discrete-time Lyapunov stability theory, and a sufficient stable condition to suppress traffic congestion is given in the form of linear matrix inequality. Also, the traffic flow evolution rules under different conditions of control gain are exhibited through numerical simulation, and the stabilization effect of the steady flow control strategy on traffic flow is verified intuitively. [ABSTRACT FROM AUTHOR]

Purpose: In an intelligent transportation system (for short, ITS) environment, a vehicle's motion is affected by the information in a large scale. The purpose of this paper is to study the integration effect of multiple vehicles' delayed velocities on traffic flow. Design/methodology/approach: This paper constructed a new car-following model to study the integration effect of multiple vehicles' delayed velocities on traffic flow. The new model is analyzed by linear and nonlinear perturbation method theoretically and also verified by simulation. Findings: It is found out that the integration of preceding vehicles' delayed velocities affect the stability of traffic flow importantly, and three preceding vehicles' delayed velocities information should be considered in real traffic. Originality/value: The new car-following model by considering the integration effect of multiple vehicles' delayed velocities is firstly proposed in this paper. The research result shows that three preceding vehicles' delayed velocities information is the best choice to stabilizing traffic flow. [ABSTRACT FROM AUTHOR]

A novel traffic lattice hydrodynamic model considering the effect of density integration is proposed and analyzed in the paper. Via linear stability theory, linear stability condition of the new model is derived, which reveals an improvement of traffic stability by considering the integration of continuous historical density information. Moreover, the nonlinear properties of the extended model are revealed through nonlinear analysis. The propagating backwards kink–antikink waves are generated by deriving the mKdV equation near the critical point and verified by numerical simulation. All the results show that the density integration effect can suppress traffic congestion efficiently in traffic lattice hydrodynamic modeling. [ABSTRACT FROM AUTHOR]

In this paper, an extended car-following model accounting for cooperation driving system with vehicle’s velocity uncertainty is proposed based on the full velocity difference car-following model. To analyze the influence of vehicle’s velocity uncertainty on traffic evolution properties, the asymptotic and local stability conditions of the new car-following model are derived respectively by using the stability theory in control theory. Numerical simulation is carried out and it shows that the vehicle’s velocity uncertainty can impact vehicle starting process and the stability of traffic flow importantly. [ABSTRACT FROM AUTHOR]

Abstract A new traffic lattice hydrodynamic model with consideration of historical current integration effect is proposed in this paper and the influence of current integration effect on traffic flow is studied through linear and nonlinear analyses. The linear stability condition obtained by linear analysis reveals that the traffic stability can be enhanced by considering the impact of historical current integration effect. Also the nonlinear analysis shows that the traffic density wave in the unstable region near the critical point can be described by the kink–antikink solution of the mKdV equation. Finally, numerical simulation is carried out to verify the analytical results and it is proved that the historical current integration effect can improve the stability of traffic flow importantly. Highlights • A new lattice hydrodynamic model considering historical current integration is built. • Linear analysis reveals the stability condition of the new model. • Nonlinear analysis uncovers the density wave in the unstable region. • The historical current integration effect can enhance traffic stability efficiently. [ABSTRACT FROM AUTHOR]

In order to reveal the self-stabilization effect of the lattice's historical information on traffic flow, a new lattice hydrodynamic model with consideration of the considered lattice's historical flow is proposed. The impact of the lattice's historical flow on traffic stability is uncovered through theoretical analyses and numerical simulation. Through theoretical analyses, the linear stability condition of the new model is obtained, and the nonlinear mKdV equation is derived to describe traffic jamming transition of the new model near the critical point. From numerical simulation, the theoretical analyses are verified and it is shown that the traffic stability can be enhanced by considering the current lattice's self-information of its historical flow. [ABSTRACT FROM AUTHOR]

To reveal the impact of the current vehicle's interruption information on traffic flow, a new car-following model with consideration of the current vehicle's interruption is proposed and the influence of the current vehicle's interruption on traffic stability is investigated through theoretical analysis and numerical simulation. By linear analysis, the linear stability condition of the new model is obtained and the negative influence of the current vehicle's interruption on traffic stability is shown in the headway-sensitivity space. Through nonlinear analysis, the modified Korteweg-de Vries (mKdV) equation of the new model near the critical point is derived and it can be used to describe the propagating behavior of the traffic density wave. Finally, numerical simulation confirms the analytical results, which shows that the current vehicle's interruption information can destabilize traffic flow and should be considered in real traffic. [ABSTRACT FROM AUTHOR]

In this paper, a new lattice hydrodynamic model with consideration of the density difference of a lattice’s current density and its anticipative density is proposed. The influence of lattice’s self-anticipative density on traffic stability is revealed through linear stability theory and it shows that lattice’s self-anticipative density can improve the stability of traffic flow. To describe the phase transition of traffic flow, the mKdV equation near the critical point is derived by using nonlinear analysis method. The propagating behavior of density wave in the unstable region can be described by the kink–antikink soliton of the mKdV equation. Numerical simulation validates the analytical results, which shows that traffic jam can be suppressed efficiently by considering lattice’s self-anticipative density in the modified lattice hydrodynamic model. [ABSTRACT FROM AUTHOR]

In order to reveal the influence of driver’s individual behavior on traffic flow more accurately, a new car-following model is proposed with consideration of multiple drives’ desired velocities. The stability criterion of the new model is derived through linear stability theory and the results show that the current driver’s desired velocity can stabilize traffic flow but the preceding driver’s desired velocity can damage traffic stability. Through nonlinear analysis, the traffic jamming transition characteristics near the critical point can be described by the kink–antikink soliton of the mKdV equation. Numerical simulation confirms the analytical results, which shows that the multiple drivers’ desired velocities play an important role in traffic evolution. [ABSTRACT FROM AUTHOR]

In this paper, a new car-following model is proposed by considering driver's desired velocity according to Transportation Cyber Physical Systems. The effect of driver's desired velocity on traffic flow has been investigated through linear stability theory and nonlinear reductive perturbation method. The linear stability condition shows that driver's desired velocity effect can enlarge the stable region of traffic flow. From nonlinear analysis, the Burgers equation and mKdV equation are derived to describe the evolution properties of traffic density waves in the stable and unstable regions respectively. Numerical simulation is carried out to verify the analytical results, which reveals that traffic congestion can be suppressed efficiently by taking driver's desired velocity effect into account. [ABSTRACT FROM AUTHOR]

A new lattice model is proposed by taking the average density difference effect into account for two-lane traffic system according to Transportation Cyber-physical Systems. The influence of average density difference effect on the stability of traffic flow is investigated through linear stability theory and nonlinear reductive perturbation method. The linear analysis results reveal that the unstable region would be reduced by considering the average density difference effect. The nonlinear kink-antikink soliton solution derived from the mKdV equation is analyzed to describe the properties of traffic jamming transition near the critical point. Numerical simulations confirm the analytical results showing that traffic jam can be suppressed efficiently by considering the average density difference effect for two-lane traffic system. [ABSTRACT FROM AUTHOR]

A new lattice hydrodynamic model for two-lane traffic system is proposed with consideration of drivers’ timid or aggressive characteristics. The effect of drivers’ timid or aggressive characteristics on the stability of traffic flow is studied via linear analysis theory and nonlinear reductive perturbation method. The linear analysis results show that the stable region for aggressive drivers is much larger than that for timid drivers, which means that aggressive drivers are much more prompt than timid drivers in stabilizing traffic flow. Moreover, we derive the mKdV equation near the critical point and obtain its kink–antikink soliton solution to describe the feature of traffic jamming transition. The good agreement between numerical simulations and analytical results reveals that drivers’ characteristics have an important role in the stability of traffic flow and traffic jamming transition in two-lane traffic system. [ABSTRACT FROM AUTHOR]

In recent years, the influence of drivers' behaviors on traffic flow has attracted considerable attention according to Transportation Cyber Physical Systems. In this paper, an extended car-following model is presented by considering drivers' timid or aggressive characteristics. The impact of drivers' timid or aggressive characteristics on the stability of traffic flow has been analyzed through linear stability theory and nonlinear reductive perturbation method. Numerical simulation shows that the propagating behavior of traffic density waves near the critical point can be described by the kink-antikink soliton of the mKdV equation. The good agreement between the numerical simulation and the analytical results shows that drivers' characteristics play an important role in traffic jamming transition. [ABSTRACT FROM AUTHOR]

A discrete-time car-following model with consideration of stable velocity control strategy is introduced and analyzed in this paper. By using the discrete-time Lyapunov stability theorem, a sufficient stable condition of the new model is derived and given in the form of linear matrix inequality. Through numerical simulation, the traffic flow evolution rules of the new model with stable velocity control strategy or not are exhibited. The results show that the unstable traffic flow is consistent to the stop-and-go density wave in real traffic. Also, traffic congestion of the new model with stable velocity control strategy can be suppressed comparing to the case without control. It is revealed that the stable velocity control strategy should be considered in real traffic to enhancing traffic stability. • A discrete-time car-following model with stable velocity control strategy is introduced. • A sufficient stable condition of the new model is derived with discrete-time Lyapunov stability theorem. • The stable velocity control strategy can suppress traffic congestion significantly. [ABSTRACT FROM AUTHOR]

A new double velocity controlled discrete-time cooperative driving system with varying time-delay is introduced in this paper on the basis of the car-following theory. The influence of the varying time-delayed information and the double velocity control method on traffic flow has been studied through theoretical analysis and numerical simulation. The theoretical analysis is conducted with the discrete-time Lyapunov stability theorem and a sufficient condition to suppress traffic congestion is given by linear matrix inequality. Through simulation, the traffic flow evolution characteristics under different varying time-delay and control signals are shown more intuitively. The results reveal that the level of traffic congestion can be aggravated if the traffic information is not obtained timely. Also it is shown that the double velocity control method can effectively reduce traffic congestion with respect to varying time-delay. • A time-delayed discrete-time traffic model with double velocity control is proposed. • The new model is analyzed with the discrete-time Lyapunov stability theorem. • Time-delayed traffic information can aggravate traffic unstable level. • The double velocity control method can effectively reduce traffic congestion. [ABSTRACT FROM AUTHOR]

A discrete-time lattice hydrodynamic model with time-delay and delay-independent traffic flux control signal is introduced. The new model is analyzed with the discrete-time Lyapunov stability theorem and a sufficient stable condition of the model is presented in the form of linear matrix inequality. Through numerical simulation, the traffic flow evolution rules under different conditions of time-delay and control gain are demonstrated and compared. All the results show that the traffic system with time-delay can easily evolve into traffic congestion comparing to the traffic system without time-delay. Also the discrete-time traffic flux control signal can improve the stable level of traffic flow. • A discrete-time traffic model with time-delay and control signal is presented. • The new model is analyzed with discrete-time Lyapunov stability theorem. • A sufficient stable condition is given in linear matrix inequality. • The control signal can improve traffic stability with respect to time-delay. [ABSTRACT FROM AUTHOR]

Under the vehicle-to-vehicle communication environment, different kinds and different ranges of traffic information could be obtained and used for the coordinated operation of road traffic system. To reveal the influence of multiple preceding vehicles' continuous self-delayed velocities information on traffic flow, an extended car-following model by considering multiple preceding vehicles' continuous self-delayed velocities is put forward. Further, the performance of the new model is studied by linear and nonlinear analyses, and also by simulation experiment. The results show that multiple preceding vehicles' continuous self-delayed velocities information affects the stability of traffic flow importantly. • A car-following model by considering multiple vehicles' information is proposed. • The unstable traffic flow is consistent with the solution of the mKdV equation. • The multiple vehicles' self-delayed velocities affects traffic stability importantly. [ABSTRACT FROM AUTHOR]

The influence of the continuous delayed optimal flow on traffic stability is studied based on a new traffic lattice hydrodynamic model in this paper. Linear analysis derives the model's linear stable condition and it shows that the stability of traffic flow is enhanced by considering the continuous delayed optimal flow. Also the feature of the unstable traffic flow is uncovered by the solution of the mKdV equation with nonlinear analysis. Finally, numerical simulation is carried out to intuitively show the stabilization effect of the continuous delayed optimal flow on traffic flow and the continuous delayed optimal flow should be considered in traffic theory. • A new macro traffic model considering the continuous delayed optimal flow is studied. • The unstable traffic flow can be described by the solution of the mKdV equation. • The continuous delayed optimal flow can improve traffic stability efficiently. [ABSTRACT FROM AUTHOR]

A new car-following model is proposed in this paper to study the interval integration effect of vehicle's self-delayed velocity information on traffic flow. The stability condition of the new model is derived through linear analysis, and the result shows that the traffic stability can be improved when a longer interval of vehicle's self-delayed velocity information is taken into account. Also it is revealed that the traffic information in the time interval which is far from the present time is more positive in stabilizing traffic flow comparing to the traffic information in the time interval which is close to the present time. Through nonlinear analysis, the mKdV equation is derived to describe the propagation properties of density wave in the unstable region. Finally, the theoretical results are confirmed by numerical simulation. • A new car-following model is proposed by considering vehicle's self-delayed velocity. • The model's properties are studied by theoretical analyses and simulation. • The vehicle's self-delayed velocity can enhance the stability of traffic flow. [ABSTRACT FROM AUTHOR]

A modified macro traffic lattice hydrodynamic model is proposed by considering the continuous self-delayed traffic flux information on traffic stability. Via linear stability theory, the influence of the continuous self-delayed traffic flux on traffic stability is derived. It reveals that the stable region in the density-sensitivity space can be enlarged by taking the continuous self-delayed traffic flux into account. Furthermore, the nonlinear feature of density wave in the unstable region is studied and it is consistent with the kink-antikink solution of the mKdV equation. Also numerical simulation is conducted to further verify the analytical results and it is shown that the continuous self-delayed traffic flux information can improve the stable level of traffic flow significantly. • A new traffic model considering the continuous self-delayed traffic flux is proposed. • The linear stability criterion of the new model is derived through linear analysis. • The mKdV equation is obtained to describe traffic density wave. • The continuous self-delayed traffic flux can reduce traffic jam efficiently. [ABSTRACT FROM AUTHOR]

This paper proposed a new macro lattice hydrodynamic model by considering the time-varying delayed information of the preceding lattice' traffic flux. The influence of time-varying delayed traffic flux on traffic flow is studied by Lyapunov stability theory and the stable condition is given in terms of linear matrix inequality. Also numerical simulations for traffic flow with time-varying delay or not are conducted to explicitly show the impact of time-varying delayed traffic flux on traffic stability. The results demonstrate that the time-varying delayed traffic flux can weaken the stability of traffic flow and the traffic flow is more likely to develop into congestion with time-varying delayed information. • A new lattice hydrodynamic model with time-varying delay is proposed. • The new model is analyzed by Lyapunov stability theory. • A stable condition of the model is given by linear matrix inequality. • Time-varying delayed traffic flux can weaken the stability of traffic flow. [ABSTRACT FROM AUTHOR]