Some Surveys in Order to Static Traffic Light Coordination

Mechanics

International Journal for Scientific Research and Development, 2015

A coordination of vehicles flows is usually reached by a cyclic operation of traffic lights and by synchronizing these cycles. During the past decades metro cities grows rapidly with industrialization, urbanization. This leads to the development of cities and a nation as well. Traffic jams, congestion becomes a major problem these days due to increase in number of vehicles. To cater these problems many approaches has been put forward to reduce the delays, congestion, stops and reduce the fuel consumption also. Particularly there is large fluctuations in number of vehicles arriving at green times which are too short or too long. In these paper attempt has been made to study various intersections so as to minimize the delays, stops and reduce fuel consumption to make a safe and healthy environment to some extend.

Vibroengineering PROCEDIA

In this paper, using discrete model of traffic flow the dynamics of traffic flow against traffic lights controlled road section points was analyzed. In the article is determined what is going on with the traffic flows when period of traffic lights switching was chosen. For the results, road points at different distances from traffic light-controlled road points were chosen. The flow, velocity and density dynamics of traffic flows are determined at different points before the traffic lights. Fundamental diagrams to determine the dependence of traffic flow and density are developed.

2013

Traffic signal timing is one of the interesting subjects that have been considered by transportation engineers and researchers. In spite of many technological and innovative solutions, fixed time controlling approach is still applying widely in the world. Signal timings are pre-defined in fixed time control and many programs can be applied for time of day. But in some cases, these programs can be insufficient for the demands occurred by variations in traffic flows. Assigned signal timings can be more or less than that of the timings required. Thus, vehicle delays can increase because of these irregular assignments. In this study, cyclic vehicle queue profile is considered for rearrangement of signal timings at isolated intersections. Observations were made at sample intersections in Denizli, Turkey. 5 isolated intersections were considered and cyclic based observations were made for peak and off-peak periods. Traffic compositions were taken into account in the observations, cyclic traffic flow profile and remaining number of vehicles for each cycle was determined. Based on these observations, average remaining queue, average discharging time of queue, remaining phase time were measured. Present cycle times were modified depending on remaining phase times and new cycle times were calculated. The average delay times of the traffic flows for new cycle times were calculated with Akcelik delay formula. In addition, they were compared to that of existing cycle time. The results showed that at least 30% improvements can be obtained by rearrangement of signal timings considering cyclic vehicle queue profile.

The paper introduces a new concept of the hierarchical regulator of the traffic flows. This regulator has two control levels: (i) the local control of micro-regions, and (ii) the coordination of whole traffic region consisting of several micro-regions. Its aim is to derive such a signal setting of the traffic lights that is optimal for the actual traffic conditions. State space model of micro-region is based on using maximum utilization of available information from all measured traffic variables and it estimates lengths of queues formed on arms of junctions with traffic lights. The queues are calculated according to the hydrodynamic analogy and their values are corrected by Kalman filtering in case of defects or measurement inadequacy. The model for the coordination is derived analogically. The control variables are relative green signals of all junctions included. Both models and all variable restrictions are linear and this fact allows us (on condition of linear criterion) to use the linear programming as the optimization tool. For this reason, the criterion is the minimization of the sum of the weighted queue lengths. The model and control strategy efficiency is demonstrated by several experiments.

International Journal of Computer Theory and Engineering, 2014

The purpose of this paper is to develop a computational model to study vehicle flow on urban roads. The model presents a study undertaken at a two-way intersection where vehicle flow is controlled by traffic lights operating according to fixed intervals of times. This model is computationally simulated using Matlab/Simulink. Several simulations were processed and in practice the model proved to be stable and reliable. It is expected that the results will contribute to the creation of a stochastic predictive model to anticipate situations that lead to traffic jams.

Indian Journal of Science and Technology, 2015

Background: Traffic management is an important tool of Intelligent Transportation System. The design of system for controlling the urban traffic dynamically provides not only the safety for pedestrians and motorists, but also saves the time and money. Method: In this paper, we describe a novel approach to manage the traffic light after measuring the accurate density with image mosaicking technique. Findings: This approach of measuring traffic density eliminates the use of conventional sensors which are sensitive to environmental changes. Even a single camera is not capable of measuring density accurately as gap between vehicles is important consideration. A single camera projection cannot capture the entire area between vehicles. So in this approach multiple cameras have been used to improve the accuracy of traffic measurement. The image mosaicking algorithm has been applied to measure one of the macro traffic flow parameter such as traffic density. The efficacy of proposed method has been evaluated, using MATLAB, AimSun and LabVIEW Software. Improvements: The result of extensive simulation indicates that this approach provides better performance in terms of increase the average moving time and decreases the average waiting time for traffic.

This paper presents a solution on the optimization of traffic lights cycle depending on the timeframe by developing a mathematical model. Based on the analysis and processing of data obtained from a traffic lights intersection with intense traffic in Sibiu, was developed a mathematical model that allows an algorithmic approach to programming sequences for ensuring a smooth traffic. The article also includes a section in which we synthesized examples of useful software in the analysis of urban traffic. The optimizing of the traffic light cycle in urban intersections, depending on the timeframe and implicitly, on the traffic volume, we consider that will increase the quality of traffic management, leading to a sustainable traffic, leading to time gain for those involved in the traffic of such intersections and also to a more efficient management of noise and gas emissions pollution from these intersections.

Self-Organization: Applied Multi-Agent Systems, 2008