scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: This study proposes a video-based detecting and positioning method by analysing distribution characteristics of traffic states in a road segment using a fuzzy-identification method to detect and positioning non-recurrent traffic incidents.
Abstract: Non-recurrent traffic incidents (accidents, stalled vehicles and spilled loads) often bring about traffic congestion and even secondary accidents. Detecting and positioning them quickly and accurately has important significance for early warning, timely incident-disposal and speedy congestion-evacuation. This study proposes a video-based detecting and positioning method by analysing distribution characteristics of traffic states in a road segment. Each lane in the monitored segment is divided into a cluster of cells. Traffic parameters in each cell, including flow rate, average travel speed and average space occupancy, are obtained by detecting and tracking traffic objects (vehicles and spilled loads). On the basis of the parameters, traffic states in the cells are judged via a fuzzy-identification method. For each congested cell, a feature vector is constructed by taking its state together with states of its upstream and downstream neighbouring cells in the same lane. Then, a support vector machine classifier is trained to detect incident point. If a cell is judged to be corresponding to an incident point at least for two successive time periods, an incident is detected and its position is calculated based on the identity number of the cell. Experiments prove the efficiency and practicability of the proposed method.

40 citations

Journal ArticleDOI
TL;DR: The simulation shows that the road capacity of the modified ITS cellular automaton model is higher than the measured data on certain highway, further indicating the important role of ITS, enlarged traffic flow and suppressed traffic jam.
Abstract: A novel cellular automaton model for traffic flow on highway is proposed considering Intelligent Transportation System (ITS). Based on the Nagel-Schreckenberg model (NS for short), it includes effective gap and brake light. Moreover, a novel concept about the variable security gap is introduced. The simulation shows that the road capacity of the modified ITS cellular automaton model is higher than the measured data on certain highway, further indicating the important role of ITS,enlarged traffic flow and suppressed traffic jam. The mixed traffic flow related to two different vehicles' velocity is studied. The simulation shows even few slow vehicles will lead to drastic decrease of traffic flow, which demonstrates the necessity to implement strictly special fast lane.

40 citations

Journal Article
TL;DR: In this paper, a discontinuity in the equilibrium relationship between speed and density was found in freeway traffic flow data, supporting the dual-mode or two-regime theories of traffic flow.
Abstract: Analysis of freeway traffic flow data reveals a discontinuity in the equilibrium relationship between speed and density, supporting the dual-mode or two-regime theories of traffic flow. This work was done during the development of an appropriate equilibrium speed-density relationship for a dynamic macroscopic freeway simulation model, FREFLO. This context assisted in clarifying the distinction between equilibrium and nonequilibrium conditions in traffic data and as a consequence made the discontinuity in equilibrium conditions perfectly evident. Use of the new relationship greatly improved the quality of FREFLO model predictions. The corresponding discontinuity in the volume that can be maintained appears to have great sisgnificance for the design of freeway control systems.

40 citations

Proceedings ArticleDOI
10 Dec 2002
TL;DR: A macroscopic traffic model and an optimization problem are presented that allows the representation of all possible traffic conditions (congested as well as non-congested) and the objective of minimizing the number of vehicles in the overall system is stated.
Abstract: Signalized urban areas are considered in order to improve the performances of traffic systems by means of real-time actions having the purpose of varying the length of traffic lights phases with respect to predefined durations. In this connection, a macroscopic traffic model and an optimization problem are presented in this paper. The proposed model allows the representation of all possible traffic conditions (congested as well as non-congested). The optimization problem is stated with the objective of minimizing the number of vehicles in the overall system, over the whole optimization horizon, by suitably choosing the duration of the phases in each semaphoric cycle.

40 citations

01 Jan 2009
TL;DR: The genetic algorithm technology in the traffic control system and pedestrian crossing is applied to provide intelligent green interval responses based on dynamic traffic load inputs, thereby overcoming the inefficiencies of the conventional traffic controllers.
Abstract: Summary The increase in urban traffic has resulted in traffic congestions, long travel times and increase hazards to pedestrians due to inefficient traffic light controls. These scenarios necessitate the use of new methods in the design of traffic light control for vehicles and pedestrian crossings. In a conventional traffic light controller, the traffic lights change at constant cycle times which are clearly not optimal. The preset cycle time regardless of the dynamic traffic load only adds to the problem. It would be more feasible and sensible to pass more vehicles at the green interval if there are fewer vehicles waiting behind the red lights or vice versa. We apply the genetic algorithm technology in the traffic control system and pedestrian crossing to provide intelligent green interval responses based on dynamic traffic load inputs, thereby overcoming the inefficiencies of the conventional traffic controllers. We apply such technology to a four-way, two-lane junction based on two sets of parameters: vehicles and pedestrians queues behind a red light and number of vehicles and pedestrians that passes through a green light. The algorithms dynamically optimize the red and green times to control the flow of both the vehicles and the pedestrians. To represent a typical traffic flow system, we use the Cellular Automata for modeling vehicular motion behind the traffic lights. We developed an algorithm to model the situation of a four-way two-lane junction based on this technology. We compare the performance between the genetic algorithms controller and a conventional fixed time controller and the results show that the genetic algorithms controller performs better than the fixed-time controller.

40 citations


Network Information
Related Topics (5)
Traffic flow
25.3K papers, 390.8K citations
90% related
Complex network
20.1K papers, 717.5K citations
72% related
Heuristic (computer science)
28K papers, 596K citations
71% related
Queueing theory
21.4K papers, 438.8K citations
69% related
Heuristic
23.1K papers, 565.2K citations
69% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202314
202237
202120
202017
201919
201822