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.

Contram: a traffic assignment model for predicting flows and queues during peak periods

Abstract: The report describes a computer-based traffic assignment and queueing model for use in the design of urban traffic management schemes. The model is called CONTRAM--CONtinuous TRaffic Assignment Model. CONTRAM requires data on time-varying flow demands (for example as occur in a "peak period"), and predicts the flows, delays and queues throughout a network of roads and junctions. The movement of traffic is modelled by grouping vehicles together to form "packets". Each packet is assigned to its minimum journey time route through the network, taking into account delays and queues at junctions. The report is divided into three parts. The first outlines the assumptions and structure of the model. The development of the model, sensitivity tests and validation work are described in the second part and examples to illustrate applications of the model are described in the third part. /Author/

Macroparticle traffic simulation model to investigate peak-period commuter decision dynamics.

Abstract: A special-purpose, macroscopic highway corridor traffic simulation model is presented. The model views traffic as discrete vehicle bunches or macroparticles that are moved according to local speeds defined by local concentrations, resulting in high computational efficiency. The model allows the investigation of commuter decision dynamics and their interrelation with timedependent congestion patterns. Two applications of the model are described illustrating its use (a) in conjunction with behavioral rules by which commuters respond to experienced congestion and (b) as part of an interactive experiment involving decision making by real commuters.

A new approach for modeling of Fundamental Diagrams

Abstract: According to the intra-vehicle interaction, a traffic flow can generally be divided into three homogeneous states (1) that of free driving, (2) that of bunched driving, and (3) that of standing. The parameter describing the state of free driving is the desired speed, for the state of bunching it is the intra-vehicle gaps (time headway) within the convoy and the mean speed of the convoy, and for the state of standing it is the maximum jam density. These are the most essential parameters which do not depend on the actual traffic situation. This paper introduces a new model which considers the Fundamental Diagram (equilibrium speed–flow–density relationship) as a function of the homogeneous states. All traffic situations in reality can be considered as combinations of the homogeneous states and therefore can be described by the essential parameters mentioned above. The non-congested (fluid) traffic is a combination (superposition) of the states of free driving and bunched driving, the congested (jam, stop, and go) traffic is a combination of the states of bunched driving (go) and standing (stop). The contribution of the traffic states within the differently congested traffic situations can then be easily obtained from the queuing and probability theory. As a result, Fundamental Diagram in all equilibrium traffic situations is derived as simple functions of the essential parameters. According to the new model the capacity of freeways and rural highways can be determined by measuring the essential parameters. This is much easier than measuring the capacity directly. Furthermore, the probabilities of the various traffic states can be obtained from the new model. This leads to new possibilities in real-time controlling and telematics. The new model is verified by comprehensive measurements carried out on freeways and rural highways in Germany.

Traffic jams induced by fluctuation of a leading car.

Abstract: We present a phase diagram of the different kinds of congested traffic triggered by fluctuation of a leading car in an open system without sources and sinks. Traffic states and density waves are investigated numerically by varying the amplitude of fluctuation using a car following model. The phase transitions among the free traffic, oscillatory congested traffic, and homogeneous congested traffic occur by fluctuation of a leading car. With increasing the amplitude of fluctuation, the transition between the free traffic and oscillatory traffic occurs at lower density and the transition between the homogeneous congested traffic and the oscillatory traffic occurs at higher density. The oscillatory congested traffic corresponds to the coexisting phase. Also, the moving localized clusters appear just above the transition lines.