Static Bottlenecks Research Articles

МОДЕЛИРОВАНИЕ ПАРАМЕТРОВ ДОРОЖНОГО ДВИЖЕНИЯ С УЧЕТОМ «УЗКИХ МЕСТ» В ТРАНСПОРТНЫХ ПОТОКАХ

The article examines a macromodel of traffic flow considering a static bottleneck in order to study the impact on traffic conditions. Analytical results show that the proposed model can qualitatively de-scribe the equilibrium flow and capacity reduction in the event of traffic congestion

Analyzing the effect of fixed and moving bottlenecks on traffic flow and car accidents in a two-lane cellular automaton model

Traffic bottleneck is considered as one of the major causes of the disturbance in traffic flow. The understanding the dynamics between vehicles and bottlenecks is crucial for enhancing traffic flow and ensuring road safety. This research examines a two-lane traffic cellular automaton model to understand the effects of static (e.g., lane reductions) and dynamic (e.g., slow-moving vehicles) bottlenecks on traffic flow and road safety. We found that at low vehicle densities, slow vehicles gravitate towards the open lane, while faster vehicles switch lanes to overtake, returning to their original lane post-bottleneck. At high densities, traffic flow near static bottlenecks ceases, independent of bottleneck length. Safety analysis shows that extended static bottlenecks reduce rear-end collision risk due to fewer lane changes and increased vehicle stationarity. At maximum density, gridlock nullifies the chance of such collisions. Our findings provide actionable insights for traffic planning focused on bottleneck management to improve road safety.

Slow nucleosome dynamics set the transcriptional speed limit and induce RNA polymerase II traffic jams and bursts.

Nucleosomes are recognized as key regulators of transcription. However, the relationship between slow nucleosome unwrapping dynamics and bulk transcriptional properties has not been thoroughly explored. Here, an agent-based model that we call the dynamic defect Totally Asymmetric Simple Exclusion Process (ddTASEP) was constructed to investigate the effects of nucleosome-induced pausing on transcriptional dynamics. Pausing due to slow nucleosome dynamics induced RNAPII convoy formation, which would cooperatively prevent nucleosome rebinding leading to bursts of transcription. The mean first passage time (MFPT) and the variance of first passage time (VFPT) were analytically expressed in terms of the nucleosome rate constants, allowing for the direct quantification of the effects of nucleosome-induced pausing on pioneering polymerase dynamics. The mean first passage elongation rate γ(hc, ho) is inversely proportional to the MFPT and can be considered to be a new axis of the ddTASEP phase diagram, orthogonal to the classical αβ-plane (where α and β are the initiation and termination rates). Subsequently, we showed that, for β = 1, there is a novel jamming transition in the αγ-plane that separates the ddTASEP dynamics into initiation-limited and nucleosome pausing-limited regions. We propose analytical estimates for the RNAPII density ρ, average elongation rate v, and transcription flux J and verified them numerically. We demonstrate that the intra-burst RNAPII waiting times tin follow the time-headway distribution of a max flux TASEP and that the average inter-burst interval [Formula: see text] correlates with the index of dispersion De. In the limit γ→0, the average burst size reaches a maximum set by the closing rate hc. When α≪1, the burst sizes are geometrically distributed, allowing large bursts even while the average burst size [Formula: see text] is small. Last, preliminary results on the relative effects of static and dynamic defects are presented to show that dynamic defects can induce equal or greater pausing than static bottle necks.

Effects of static bottlenecks on traffic flow in urban road network

Existing traffic flow models do not consider the effects of road static bottlenecks on traffic flow. In this paper, a modified macroscopic continuum model for traffic flow on urban road network with static bottlenecks is presented. The model takes into account the fluctuations of traffic flow considering static bottlenecks during the morning peak period. The model results show that existence of static road bottlenecks with various configurations cause traffic flow instabilities. This phenomenon lead into stop-and-go traffic flow conditions under the moderate density and reduction of the traffic system’s efficiency. Furthermore, results show that an increase in traffic density is accompanied by a significant decrease of speed which adversely influences performance of roadway and decrease the traffic system’s efficiency and thus resulting to the occurrence of congestions. The methodological aspects of the study and results will enable traffic engineers and planners to assess and improve existing urbanroad networks.
 Keywords: Traffic flow, Bottlenecks, stability, Stop-and-go traffic, System’s efficiency, Congestion.

Front tracking transition system model with controlled moving bottlenecks and probabilistic traffic breakdowns

Cell-based approximations of PDE traffic models are widely used for traffic prediction and control. However, in order to represent the traffic state with good resolution, cell-based models often require a short cell length, which results in a very large number of states. We propose a new transition system traffic model, based on the front tracking method for solving the LWR PDE model. Assuming piecewise-linear flux function and piecewise-constant initial conditions, this model gives an exact solution. Furthermore, it is easier to extend, has fewer states and, although its dynamics are intrinsically hybrid, is faster to simulate than an equivalent cell-based approximation. The model is extended to enable handling moving bottlenecks as well as probabilistic traffic breakdowns and capacity drops at static bottlenecks. A control strategy that utilizes controlled moving bottlenecks for bottleneck decongestion is described and tested in simulation. It is shown that we are able to keep the static bottleneck in free flow by creating controlled moving bottlenecks at specific instances along on the road, and using them to regulate the incoming traffic flow.

Recurrent and non-recurrent bottleneck analysis based on traffic state rank distribution

ABSTRACTRoad network bottleneck would shift around according to the demand or supply, and therefore behaves differently from static bottlenecks such as on–off ramp and lane drop. The identification of dynamic bottlenecks is crucial for management and control. Traditional methods use direct measurements. Such methods may be biased and can only analyze the recurrent or non-recurrent bottleneck, not both. This research uses rank measurement based on speed to identify bottlenecks. The underlying idea is that bottleneck links or areas have relatively lower rank, and neighboring links covered by the same congestion event should behave similarly with respect to the rank distribution. The identification procedure is implemented by three steps: firstly, the rank distribution is fit using Gaussian Mixture Model (GMM), and then the Kullback–Leibler (KL) divergence is employed to measure the similarity between adjacent links; at last, the bottleneck areas are clustered. Using rank information would enhance the bottleneck identification performance.

Interference of two codirectional exclusion processes in the presence of a static bottleneck: A biologically motivated model.

We develop a two-species exclusion process with a distinct pair of entry and exit sites for each species of rigid rods. The relatively slower forward stepping of the rods in an extended bottleneck region, located in between the two entry sites, controls the extent of interference of the codirectional flow of the two species of rods. The relative positions of the sites of entry of the two species of rods with respect to the location of the bottleneck are motivated by a biological phenomenon. However, the primary focus of the study here is to explore the effects of the interference of the flow of the two species of rods on their spatiotemporal organization and the regulations of this interference by the extended bottleneck. By a combination of mean-field theory and computer simulation, we calculate the flux of both species of rods and their density profiles as well as the composite phase diagrams of the system. If the bottleneck is sufficiently stringent, then some of the phases become practically unrealizable, although not ruled out on the basis of any fundamental physical principle. Moreover, the extent of suppression of flow of the downstream entrants by the flow of the upstream entrants can also be regulated by the strength of the bottleneck. We speculate on the possible implications of the results in the context of the biological phenomenon that motivated the formulation of the theoretical model.

Phase diagram of a continuum traffic flow model with a static bottleneck

The phase transitions are investigated in a continuum speed-gradient model with a static bottleneck under open boundary conditions. The bottleneck situation has been studied using two different approaches—explicit and implicit. The phase diagrams showing different traffic states are presented. The effect of strength of bottleneck has been analyzed, and it is found that the strength parameter has no qualitative effect in the explicit case while has considerable effect in the implicit case. Furthermore, the results of both the approaches are compared, and the consistency between them is discussed.

An extended macro model for traffic flow with consideration of multi static bottlenecks

In this paper, we propose a macro model with consideration of multi static bottlenecks to study the impacts of multi static bottlenecks on traffic flow. The numerical results show that the influences are related to the number of static bottlenecks, the distance between two adjacent static bottlenecks and the initial density.

A Macro Model for Traffic Flow with Consideration of Static Bottleneck

In this paper, we develop a macro model for traffic flow with consideration of static bottleneck to explore the impacts of static bottleneck on traffic flow. The analytical and numerical results show that the proposed model can qualitatively describe the equilibrium flux, uniform flow and small perturbation under the action of a static bottleneck.

Geometry of a centrosymmetric electric charge

The gravitational description given for an electric charge on the basis of exact solution of the Einstein-Maxwell equations eliminates Coulomb divergence. The internal pulsating semiconfined world formed by neutral dust is smoothly joined with parallel Reissner-Nordstrem vacuum worlds via two static bottlenecks. The charge, rest mass, and electric field are expressed in terms of space curvatures. The internal and external parameters of the maximon, electron, and the universe form a power series.