Over the past decade, a number of manuals have been developed for rural road roundabouts in the Russian Federation. However, two- and three-lane roundabouts are designed and operated in cities of the ...Russian Federation do not yet have manuals that take into account the specific features of this urban intersections. The development of such do not yet have manuals involves defining all multi-lane roundabout characteristics which used in consistent calculations of capacity, traffic delays and queue length. The objective of the study is to develop a methodology of multi-lane roundabout capacity estimation. At this stage, a study was done to determine the values of critical headway and follow-up time for two-lane roundabouts. Research methodology. Video rings were received from the city of Bratsk, Petrozavodsk, Pskov. The headways measured between the front bumpers of cars, were recorded on each lane of the circular roadway. Accepted and rejected headways were highlighted, as well as the number of vehicles using each accepted headway. Critical headway and follow-up time were determined using linear regression models. Study Result. It was found that the values of critical headway and follow-up time of the left and right entry lanes have different values. These results proved the validity of capacity calculation methods based on a separate consideration of each of entry lane. Objectives for further research. Further research will focus on estimation of critical headway and follow-up time for three-lane roundabouts. It is also necessary to establish the influence of traffic volumes on the headway distribution on two- and three-lane circular carriage way. Consistent solving of mentioned above research tasks will allow to form an estimation methodology for all characteristics of multilane roundabouts. Key words: two-lane roundabouts, conflict points, critical headway, follow-up time, regression analysis.
Background: Traffic conflict points are the areas formed by conflict movements in the traffic flow. The numbers and distributions of different types of traffic conflict points are often used to ...evaluate access management designs and the safety performance of intersections. Customarily, determining the number of different types of traffic conflict points is based on the manual drawing method, which is troublesome and makes using computerized procedures for calculation of the number of traffic conflict points difficult.
Objective: The present work aims to quickly compute the number of traffic conflict points between vehicles at major-minor highway intersections.
Methods: The concept of "virtual lanes" is defined, and the virtual lane conversion method is proposed. Based on actual and virtual lanes, vehicular movements, and traffic control modes, a generalized method to determine the number of traffic conflict points between vehicles at major-minor highway intersections is developed.
Results: A procedure for determining the number of conflict points is presented. A similar HCM LOS-style form and computer software were designed to help calculate the number of conflict points.
Conclusions: Applications show that the method can efficiently and accurately determine the number of traffic conflict points between vehicles at major-minor highway intersections.
A case of what? Basic, Goran
Journal of comparative social work,
2013, Letnik:
8, Številka:
2
Journal Article
Recenzirano
Odprti dostop
“Collaboration” is generally portrayed as being beneficial to authorities, even if previous collaborative research shows that conflicts are common between authorities who are supposed to cooperate. ...What takes place when different actors in the collaboration meet in practice? And what is the best way to analyse this? In qualitative studies, it is often problematic to go from an exhaustive analysis of individual empirical instances to an overall picture of the context or phenomenon in which all instances taken together can be viewed as a case. Years of close engagement with the data may interfere with the analyst’s capacities and opportunities to contextualize a study more broadly and theoretically, and detailed knowledge about a range of situations in the field may make novel contextualizations difficult. This article discusses how to overcome such obstacles, using examples from a study about a “collaboration” project in Swedish youth care.
A method is introduced for computer modeling of traffic at a signalized intersection of urban roads treated as a random process. It is based on the use of statistical dependencies for temporal ...headways between subsequent vehicles. Methods for obtaining such dependences from monitoring data are considered. Examples of calculations for a T-junction are presented and analyzed.
The prerequisites for the use of automatic control methods for traffic light regulation of the intersection with constant monitoring of the local traffic flow are analyzed. A set of possible ...controlled indicators of local traffic is defined. The methodology and results of computer experiments to identify the most efficient methods of traffic regulation are presented.
In this paper, we propose a construction process that enables the transformation of an urban traffic network using a cellular automata lattice. An abstract network hierarchy is defined which allows ...us to describe the important properties of an urban traffic network layer by layer. The cellular automata lattice is extended with three additional types of cells that permit the modelling of conflict points at intersections. A supporting model of vehicle behaviour based on traffic cellular automata is also extended with rules that allow vehicles to move properly within the extended cellular automata lattice.
The method of controlling an intersection by jointly choosing a phase-wise traffic separation scheme and optimizing traffic light control at the required intensity of traffic flows along the ...directions of movement is being developed, taking into account the interaction of clusters on exit roads. The sequence of passage schemes on phases and temporal phase shifts for individual routes are optimized.
The work is devoted to the study of the problem of structural and parametric control of traffic flows within a fragment of an urban road network with regulated intersections, based on fixing the ...current state of traffic and historical data. The goal of the traffic control is the efficient and safe implementation of transport demand at the local level. The detailed structure of the road network is formally described, and the description of probabilistic dependencies characterizing the passage of traffic flows through a certain intersection from the standpoint of traffic control is given. On this basis, formulations and methods for solving specific control problems are proposed, and relationships between them are determined.
Intersection control by joint selection of a phase-wise traffic separation scheme and optimization of traffic light control at the required traffic flow (TF) intensity on each passage directions, ...including branching routes, is considered taking into account the probabilistic nature of the TFs. The formulations and methods for solving optimization problems using the model of TF on the road lane are presented.
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