No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
An effective and widely-applied redesign for traffic circle
Abstract
In this paper, we propose an effective redesign for traffic circle for the sake of extensive use. Three evaluation indexes are used to classify the category of district where a traffic circle belongs to. With the help of the most essential evaluation index, through calculating from two differently improved methods which are distinguished by whether use traffic lights or not, an optimal proposal can be obtained after comparing the outcomes. In addition, correspondingly implemental arrangements can be set up for concrete traffic construction. Our experimental results show that the achievement of this redesign is significantly widely-applied.
... Traffic circles has been reported to be useful in controlling traffic and relaxing the traffic pressure [1][2][3][4][5]. A growing number of mathematic methods to estimate the capacity of the traffic circle the circle have been introduced, such as Erlang distribution [6] [8]and automatic control theory [7]. ...
In this paper we use queuing theory to analysis the incoming traffic, developed an effective way to control the traffic of a circle by using stop signs and yield signs,and calculated the traffic capacity and average waiting time of this method. Then, we use signals to control the traffic and improve the original method by a analysis the ways the car can pass through the circle crossing. Taking into account of the traffic flow in the different time of a day, we got the light's signal period to adapt to the features of the traffic flow.
The goal of the paper is to test the performance of Q-learning for adaptive traffic signal control. For Q-learning algorithm, the state is total delay of the intersection, and the action is phase green time change. The relationship between phase green time change and action space is discussed. The performance between Q-learning and fixed cycle signal setting for isolated intersection is compared. The computation results show that Q-learning for traffic signal control can achieve lesser delay for variable traffic condition.
The paper compares the results of extensive measurements of the capacity of nonpriority traffic streams at major/minor junctions and roundabouts with the predictions of models based on gap-acceptance theory. There are significant differences in the form of the relation between the capacity and the traffic flows in the priority streams. The simple gap-acceptance models are poor predictors of the capacity in the United Kingdom, for they seriously overpredict at low values of priority flow and underpredict at high values. At the lower values the gap-acceptance predictions can only be made to agree with the results of the empirical measurements by introducing a dependence of the “move-up” times on the value of the flows in the priority streams. The discrepancies at the higher values of priority flow are probably due to gap-forcing and priority reversal, both of which are commonly observed in the United Kingdom, but whose occurrence may vary from one country to another as a result of differences in driver behavior, legal sanctions, and enforcement policies. Several gap-acceptance models of roundabout capacities are compared and are found to be mutually inconsistent.
The paper presents the application of the group traffic control
methodology to signal controlled roundabouts. This methodology is based
on the group model of traffic in street network. There are three types
of elements in the model: groups of vehicles, road segments and control
signals. Interactions among vehicle groups and the influence of signal
or road on their movement are described by the set of seven elementary
transformations. In this framework the optimal cycle time and offsets
are derived for four-arm roundabout excluding the blocking back effect
from circulating carriageway. The new method was proved to be very
efficient in stops, delay and capacity on two roundabouts in
Poznan
When the circulatory roadway of a roundabout has more than two lanes, the vehicles' weaving and merging cause large traffic and safety problems. In this paper, a new method of traffic-signal control for modern roundabouts is proposed to solve problems by eliminating the conflict points and weaving sections at a roundabout with different traffic-flow rates on each approach, which normally appear in the real world. A second stop line is set exclusively for the left-turn traffic on the circulatory roadway. It is beside the first stop line on the approach. Traffic signals are installed before each stop line to eliminate the conflicts between the traffic flows on the approaches and the left-turn traffic flows on the circulatory roadway. Left-turn vehicles on the circulatory roadway will stop before red signals to avoid weaving. Equations are derived to compute the signal cycle length and the green time for each traffic flow, considering the limited queue on the circulatory roadway. Capacity and delay are also formulated to evaluate the roundabout's performance. This traffic-signal control has a successful application of a roundabout in Xiamen, China, to solve the very serious traffic-congestion problem. The signal-timing scheme was computed with the proposed equations, as well as the capacity and delay. Pictures taken before and after the improvement show the operation. After the improvement, the roundabout capacity increases 72.1% and the average delay of each vehicle decreases by 20 s.
An analysis of road junctions without traffic lights
- Yu Zhi-Qing
Traffic management and control
- Yang Pei-Kun
- Wu Bing
Gao Hai-long, A study of the model construction for roundabout's capacity
- Xiang Qiao-Jun
- Wang Wei
- Chen Bing
- Chang Yu-Lin
Design of roundabout at road intersection
- Wang Yang-Zhen