Traffic wave

About: Traffic wave is a research topic. Over the lifetime, 2106 publications have been published within this topic receiving 62117 citations. The topic is also known as: phantom traffic jam & ghost jams.

System and method for radio wave based vehicle-to-vehicle spreading of road traffic information

Abstract: The present invention relates to a system and a method for radio wave based vehicle-to-vehicle spreading of road traffic information, wherein each of the vehicles (101-104) is provided with a radio transmitter, a radio receiver, a location positioning device and a message forwarding timer. The method comprises the steps of recognizing, by a first vehicle (101), a road traffic event occurred on a section of a road (105) on which said first vehicle is travelling; generating, by said first vehicle, a piece of road traffic information relating to the road traffic event; generating, by said first vehicle, a first road trajectory description information including at least data for the identification of said road section; generating, by said first vehicle, a first message containing at least a unique identifier for said message, said piece of road traffic information, the location of the vehicle sending the first message, said location being determined by its location positioning device, and said first road trajectory description information; transmitting, by said first vehicle, said first message by radio message spreading; receiving, by at least one second vehicle (102,103,104).

Cyber-physical systems: A framework for dynamic traffic light control at road intersections

Abstract: Traffic control at road intersections is based on traffic lights (TLs). The control mechanism typically used for traffic lights operates based on a periodic schedule to change the light (red/yellow/green). In many cases, a different schedule is used in late night/early morning hours. This fixed control mechanism does not adequately account for changing traffic conditions, and is unaware of/unresponsive to congestion. In this work, we propose a framework for dynamic traffic light control at intersections. The framework relies on a simple sensor network to collect traffic data and includes novel protocols for traffic flow control to handle congestion and facilitate flow. We show that our proposed algorithms have low overhead and are practical to employ in live traffic flow scenarios. Through extensive simulations, we demonstrate the benefits of our framework in optimizing traffic flow metrics, such as traffic throughput, average vehicle waiting time, and vehicle waiting line length.

Modeling and simulating traffic congestion propagation in connected vehicles driven by temporal and spatial preference

Abstract: Differing from the traditional traffic, connected vehicles enable information sharing between vehicles at vicinity to facilitate cooperative path planning, which may positively affect the congestion propagation process. In this paper, we propose to modeling and simulating traffic congestion propagation in such new situation where the path planning is driven by a temporal or spatial preference with aims at investigating the effects of various factors on traffic congestion, e.g. traffic light, mobility pattern, traffic density and communication radius. Simulations show that the traffic congestion is indeed affected by the concerned factors; however, the traffic congestion fails to be mitigated persistently as the communication radius increases beyond a certain threshold. The result is helpful for understanding the traffic congestion propagation in connected vehicles.

An Exact Graph Structure for Dynamic Traffic Assignment: Formulation, Properties, and Computational Experience

Abstract: The objective of this paper is to present an exact graph structure for dynamic traffic assignment (DTA), thereby providing a clear theoretical bridge between dynamic traffic assignment and graph theory. An exact graph-based formulation (GBF) with origins in the cell transmission model (CTM) is presented for the single destination DTA problem. The “cell” concept is formalized and projected in graph theoretic terms, leading to the graph theoretic cell transmission model (GTCTM). The fundamental difference with the CTM and existing DTA formulations (linear, minimum cost flow sub-structure) is in the modeling of backward propagating traffic waves, which is extensively discussed. The system optimal (SO) and the user equilibrium (UE) traffic assignment objectives are modeled on the same graph structure with modified weights. Properties of the corresponding graph are recognized: (i) the GBF is acyclic, and (ii) every edge-disjoint path is also a node-disjoint path. The existence of a solution and the property of uniqueness are analyzed using the GTCTM basis. Experimental results indicate significant benefits in computational time; it is the direct outcome of reducing the complexity of a linear formulation to minimum cost flow.

Fundamental diagram in traffic flow of mixed vehicles on multi-lane highway

Abstract: We study the fundamental diagram for traffic flow of vehicular mixture on a multi-lane highway. We present the car-following model of multi-lane traffic in which slow and fast vehicles flow with changing lanes. We investigate the traffic states of the vehicular mixture under the periodic boundary. Two values of the current appear at a density and two current curves are obtained. Vehicles move with changing lanes in the traffic state of high current, while vehicles move without changing lanes in the traffic state of low current. They depend on the density, the fraction of slow vehicles, and the initial condition. In the high-current curve, the jamming transition between the free flow and the jammed state occurs at a low density. The fundamental diagrams (current–density diagrams) are shown for the single-lane, two-lane, three-lane, and four-lane traffics.