Intersection Delay Model Research Articles

Research on coordinated control optimization of adjacent intersections based on numerical solution

In order to improve the efficiency of traffic flow and reduce the delay of arterial intersections, a coordinated signal control method based on numerical solution is proposed. Firstly, considering the factors such as the shortest green time and saturation of a single intersection, the intersection delay model is established. Secondly, the traffic capacity of the trunk line is improved by optimizing the public cycle and the green ratio of each intersection. Finally, an optimization model with minimum delay as the optimization objective is constructed, and the signal coordination of arterial intersections is realized by taking Yancheng City as an example. The results show that the coordinated control model of adjacent intersections based on the numerical method can reduce the average vehicle delay of two-way vehicles, achieve the purpose of green wave coordinated control of road sections, and improve the road traffic capacity.

Intelligent vehicle control at signal‐free intersection under mixed connected environment

Conflict vehicle movements at intersections are one bottleneck of traffic mobility on urban networks. Recently, with the development of connected vehicles, regulating conflict movements by controlling individual vehicles to improve intersection performance has attracted a lot of research efforts. This study aims at developing an advanced vehicle control system with connected vehicles to reduce vehicle delays at intersections without the help of signals. An intersection delay model is proposed to predict the total vehicle delay at one intersection and to search for the optimal speed control actions to manage traffic under mixed connected and non-connected vehicle environment. The simulation experiments illustrate that the control system is able to reduce average vehicle delay by up to 95%, and the sensitivity analysis of vehicle demand and market penetrate rates of connected vehicles is also conducted to understand the benefits of the system at different traffic and connected vehicle environments.

Optimal Evacuation Strategy for Parking Lots Considering the Dynamic Background Traffic Flows.

An optimal evacuation strategy for parking lots can shorten evacuation times and reduce casualties and economic loss. However, the impact of dynamic background traffic flows in a road network on the evacuation plan is rarely taken into account in existing approaches. This research develops an optimal evacuation model with total evacuation time minimization by dividing the evacuation process in a parking lot into two periods. In the first period, a queuing theory is used to estimate the queuing time, and in the second period, a traffic flow equilibrium model and an intersection delay model are employed to simulate vehicles’ route choice. To deal with these models, a modified ant colony algorithm is developed. The results of a numerical example prove that the proposed method has an advantage in improving evacuation efficiency. The results also show that background traffic flows affect not only vehicles’ average queuing time in parking lots but also optimal evacuation route choice. Additionally, a sensitivity analysis indicates that the minimum threshold of headway time that allows vehicles out of a parking lot to merge into the background traffic flows on the roads connecting the exits has a great impact on average queuing time, average travel time, and total evacuation time.

A New Approach for Real-Time Traffic Delay Estimation Based on Cooperative Vehicle-Infrastructure Systems at the Signal Intersection

Confined by the real-time and accuracy of traditional traffic collecting parameters, the existing traffic delay estimation models are generally with poor performance in guiding practical applications. In the Cooperative Vehicle-Infrastructure System, the real-time entire space-time driving state information of a single intelligent vehicle provides new data supporting for road traffic status evaluation. Fully extracting the value of this kind of new data, this paper proposes a new real-time traffic delay estimation method based on the Webster signalized intersection delay model. Taking each intelligent vehicle as a benchmark point, the vehicle arriving/leaving characteristics of the signalized intersection are spatially interpolated by the stopping state of a small amount of benchmark vehicles. In order to obtain the critical queuing dissipation point, the linear fitting method is used to forecast the critical stopping time and further the Markov model is used to estimate the number of queuing vehicles at the critical stopping time. Based on the real-time vehicle queuing characteristics, a new traffic delay estimation model is built according to the Webster estimation mechanism. The case study shows that, compared with the traditional Webster model, the proposed method can effectively improve the traffic delay estimating accuracy.

Simulation of Signalized Intersection Model

Signalized intersection delay is an important evaluation index of the signalized intersection capacity and level of service. This paper presents a signalized intersection delay model for signalized intersection. The model uses time series and queuing theory. It discusses the operation characteristics of the process of arrival and leaving and optimizes the intersection signal timing and gets the best signal cycle time. A scientific model and a more complete analysis are founded in the paper. These methods have a good reference value to the relevant departments.

Research of Signalized Intersection Delay Problem by Time Series and Queuing Theory

Signalized intersection delay is an important evaluation index of the signalized intersection capacity and level of service. This paper presents a signalized intersection delay model for signalized intersection. The model uses time series and queuing theory. It discusses the operation characteristics of the process of arrival and leaving and optimizes the intersection signal timing and gets the best signal cycle time. A scientific model and a more complete analysis are founded in the paper. These methods have a good reference value to the relevant departments.

Research of Signalized Intersection Delay Model by Using Optimization Method

By using optimization method, this paper has set up vehicle delay models of signalized intersection which based on vehicle average delay minimum, each phase remain time equal and each phase remain time balance. By using a real intersection’s geometry and traffic flow data, this paper has also set up the phase time with the above models, studied the results and evaluated these models

Comparison of Delay on Arterials by Simulation and Highway Capacity Manual Computations

A comparison of delay on arterials was made using simulation and Highway Capacity Manual (HCM) computations. An extensive set of cases was defined over a range of flow rates, free-flow speeds, and signals per mile. Delay was calculated on the basis of the HCM computation for the specified signal progressions. The same cases were run using a specially revised version of the NETSIM microscopic simulation model. Detailed analysis showed that the discrepancies were traceable to the progression factor (PF). Corrections can be made (and are outlined) but must be done with care. There are a number of complex mechanisms at work. The primary result of this study may be clarifying the insufficiency in the current PF algorithm. The expectation that a single multiplicative factor could provide the needed correction to a long-link random-arrival steady-state delay model (that is, the existing HCM delay model), so that it could be a network-based model for delay estimation, appears to be simply unrealistic. For these and other reasons, research is focusing on the creation of a time-varying intersection delay model, building from basic principles.