Vehicle Queue Research Articles

MODELLING OF EXPECTED TRAFFIC SMOOTHNESS IN URBAN TRANSPORTATION SYSTEMS FOR ITS SOLUTIONS

In urban networks, with dense traffic flows and a high risk of the disruption (even in the form of a short queue of vehicles) the probability of occurrence of such a situation (disruption and queue) is a better measure of the probabilistic description of the capacity constraints than the expected waiting time in the queue, because the probability takes into account the risk of delay in the traffic flow from the point of view of the person that plans a trip. The functions of expected smoothness of the traffic flows in the elementary nodes and the expected waiting time in the queue for different packages of ITS services have been presented in the mathematical forms.

Review, Experimental Evaluation and Policy Considerations of a Directional Time of Day Truck Restriction on Highways

The paper reviews several strategies of restricting or separating trucks from the regular traffic stream. Typical truck restriction policies focus on leftmost lanes restriction, which has been shown by several studies to have some advantages. However, those studies clearly show that vehicle queue lengths in the vicinity of critical merging areas increase significantly as the percentage of trucks increases. Therefore, this study examines a different policy—one which investigates traffic efficiency gained by restricting heavy truck traffic in one direction—in this case, westbound on Highway 1 in Israel—during afternoon peak hours. Similar policies of utilizing a specific vehicle category (e.g. passenger cars or trucks) in different daily time periods or physical separation of homogenous traffic of passenger cars in the inner lanes and mixed traffic in the outer lanes, were recommended in Italian motorways and in New Jersey Turnpike dual-dual freeways respectively.Highway 1 is a freeway connecting Jerusalem and Tel Aviv that passes by Ben-Gurion International Airport. The major objective of this study is to estimate the benefit of restricting truck traffic in the traffic stream according to three traffic-flow parameters: average travel time, total travel time, and average traffic speed. Analysis of the results, which consider the significant differences of 30-minute time period samples (“before-after” truck restriction), shows that prohibiting trucks in all lanes in one direction during the peak afternoon period of 16:00-18:00 improved all three traffic flow parameters by 8%-12%. Generally a steep grade from which truck traffic is banned is correlated with an improvement in traffic flow. In our case, Highway 1 road segments 1 and 2 and 4, which have steep grades (longitudinal grades), incorporated the most significant improvements in the traffic stream parameters examined.

Stochastic programming model for oversaturated intersection signal timing

In large cities, signalized intersections often become oversaturated in rush hours due to growing traffic demand. If not controlled properly, they may collectively result in serious congestion. How to schedule traffic signals for oversaturated intersections has thus received increasing interests in recent years. Among various factors that may influence control performance, uncertainty in traffic demand remains as an important one that needs to be further studied. In some recent works, e.g., Yin (2008) and Li (2011), robust optimization models have been utilized to address uncertainty in traffic demand and to design fixed-timed signal control for oversaturated intersections. In this paper, we propose a stochastic programming (SP) model to schedule adaptive signal timing plans that minimize the expected vehicle delay. Our numerical experiments show that the proposed SP model better describes the fluctuations of traffic flows and outperforms the deterministic linear programming (LP) model in total vehicle delay, total throughput, and vehicle queue lengths. Moreover, we compare the proposed SP model with the adaptive signal control model proposed in Lin et al. (2011) to provide insights on such improvements from green time utilization and queue balancing perspectives. Furthermore, we study the feasibility of the proposed SP model in practice, with an emphasis on the required sample sizes.

Simulation Analysis and Improvement of the Vehicle Queuing System on Intersections Based on MATLAB

In order to reduce the traffic congestion and to enhance the capacity of urban road intersections, this paper builds a model of the vehicle queuing system for the intersection by queuing theory Based on Monte Carlo algorithm, this paper carries out simulation and analysis of the vehicle queuing system in the intersection by MATLAB, analyses, the status of vehicle queue to reduce the vehicle queue waiting time, and explores methods to solve the problem of vehicle queues at intersections. The optimal design for vehicle operating conditions has also been implemented from the perspec- tive of the queuing theory, facilities planning, Ergonomics and the management system. The results show that the analysis and improvement to the existing access program of the intersection can effectively relieve the vehicles queuing problem and promote the social service intensity of urban transportation system.

Traffic lanes for vehicles of mass public passenger transport on city streets

Some of the basic measures of regulating public mass passenger transport in a city network are the introduction and management of traffic lanes reserved for the public transportation. These traffic lanes are important for several reasons: faster moving and shorter travelling time for the vehicles, reducing operating costs, improving the safety, increasing passenger comfort, maintaining of the timetable quality, etc. In most cities, an intensive use of the public transport is concentrated in the morning and the afternoon peak period. The state of the public transport system during these periods is reflected in the crowds inside the vehicles, long vehicle queues at intersections and at bus stops, which cause congestion on the streets and result in delays of public transport vehicles. This paper provides an overview of the current situation on an example in the city of Belgrade. The capacity and the quality of service for the street surfaces reserved for the public transportation vehicles were analysed on the aforementioned example.

Using the General Link Transmission Model in a Dynamic Traffic Assignment to Simulate Congestion on Urban Networks

This article presents two new models of Dynamic User Equilibrium that are particularly suited for ITS applications, where the evolution of vehicle flows and travel times must be simulated on large road networks, possibly in real-time. The key feature of the proposed models is the detail representation of the main congestion phenomena occurring at nodes of urban networks, such as vehicle queues and their spillback, as well as flow conflicts in mergins and diversions. Compared to the simple word of static assignment, where only the congestion along the arc is typically reproduced through a separable relation between vehicle flow and travel time, this type of DTA models are much more complex, as the above relation becomes non-separable, both in time and space.Traffic simulation is here attained through a macroscopic flow model, that extends the theory of kinematic waves to urban networks and non-linear fundamental diagrams: the General Link Transmission Model. The sub-models of the GLTM, namely the Node Intersection Model, the Forward Propagation Model of vehicles and the Backward Propagation Model of spaces, can be combined in two different ways to produce arc travel times starting from turn flows. The first approach is to consider short time intervals of a few seconds and process all nodes for each temporal layer in chronological order. The second approach allows to consider long time intervals of a few minutes and for each sub-model requires to process the whole temporal profile of involved variables. The two resulting DTA models are here analyzed and compared with the aim of identifying their possible use cases.A rigorous mathematical formulation is out of the scope of this paper, as well as a detailed explanation of the solution algorithm.The dynamic equilibrium is anyhow sought through a new method based on Gradient Projection, which is capable to solve both proposed models with any desired precision in a reasonable number of iterations. Its fast convergence is essential to show that the two proposed models for network congestion actually converge at equilibrium to nearly identical solutions in terms of arc flows and travel times, despite their two diametrical approaches wrt the dynamic nature of the problem, as shown in the numerical tests presented here.

Analysis of evolution mechanism of traffic energy dissipation by considering driver’s forecast effect

Starting from the full velocity difference model, an extended car-following model is proposed by considering the influence that in real traffic the driver’s forecast has an effect on car-following behavior of traffic flow. The mechanism how the stability and energy dissipation of traffic flow are in fluenced by the driver’s forecast effect is revealed by the application of the proposed new model. The linear stability condition of the new model is derived theoretically through linear stability theory. The phase diagram of linear stability condition is divided into two regions by each stability curve: the stable and unstable regions. And the corresponding stable region will be enlarged with the increase of driver’s forecast time, hence the traffic condition will be improved through considering driver’s forecast effect. By numerical simulation method, the space-time evolution relation between the velocity and headway of vehicles in car-following queue is investigated systematically under the influence of driver’s forecast. In the same time, the evolution mechanisms of the overall average energy dissipation of traffic flow and individual vehicle energy consumption with the addition of small disturbance are discussed explicitly under a periodic condition, and it is discovered that the overall average energy consumption in traffic flow and the energy dissipation of individual vehicle is accompanied by a complex critical phase transition process. Good agreement between the numerical simulation and the theoretical analysis show that by considering of driver’s forecast effect, not only the stability of traffic flow is enhanced obviously, but the energy consumption is reduced remarkably as we expect. Furthermore, it is verified that both the overall average energy consumption of the considered traffic flow and the energy consumption of an individual vehicle are reduced gradually along with the increase of driver’s forecast time. On the other hand, numerical simulation results verify that the shortcoming of negative speed appearing in the full velocity difference model with low reaction coefficient can be effectively avoided by increasing the driver’s forecast time in the improved model, which means that the dynamic characteristics of traffic flow can be described more precisely by the proposed model.

Real-Time Traffic Signal Control Based on Kalman Filtering Theory

Aiming at the problem that individual control of urban traffic lights and stable signal timing. This paper proposed a real timing control method of traffic lights which based on Kalman filter. This method use Kalman filter to predict the next time traffic flows and then update the signal timing. By field researching the traffic flow of intersection in peak hour and predicting the traffic flow. Then update the signal timing. Meanwhile using the VISSIM to simulate the intersection. The result of the simulation shows that the length of vehicle queue decreased significantly and the number of stops dropped. The efficiency of access has been greatly improved.

车道占用对城市道路通行能力的影响分析

文章分析了车道占用对城市交通能力的影响，在实验视频数据基础上建立方差分析模型和基于微分方程的多元回归模型，并对结果进行定性分析和定量计算。首先，通过观察案例视频得到与道路通行能力相关的数据，通过MATLAB插值拟合；其次，建立方差分析模型，进而探究了不同车道被占用对城市道路通行能力的影响差异。然后通过微分模型，给出了排队长度和事故横截面的实际通行能力、事故持续时间及路段上游车流量之间的关系；最后，将模型结果和实际结合，计算出实际事故持续时间。 This paper analyzes the line occupation effects on traffic capacity, and establishes ANOVA model and multiple regression model built on differential equations based on the video data, and do qualitative analysis and quantitative calculations for results. Firstly, the data which was associated with road capacity was obtained by observing the video; then through MATLAB, inter-polation fitting was done. Secondly, it established variance analysis model, and then explored the impact of different occupied lanes on traffic capacity. Then by using the differential model, the re-lationship among vehicle queue length, traffic capacity, traffic accident time and traffic flow was obtained. In the end, combining the theory of model with practice, the duration of the actual acci-dent was calculated.

交通事故对路段通行能力影响作用分析

本文针对交通事故占用的不同车道，从道路横截面的车流量、车辆排队长度研究交通事故对城市道路通行能力的影响。通过从视频中截取事故道路横断面的车流量、路段上游车流量、路段车辆排队长度等数据，分析交通事故持续期间路段通行能力的变化过程，并分析当事故占用不同车道时，通行能力变化的差异及原因。 The effects of traffic accident on road traffic capacity have been researched from some aspects in-cluding different lanes occupied, traffic flow of the road cross section and the length of vehicle queue. Some data after traffic accident has happened, such as the traffic flow from the upper section of accidence, have been collected to analyze the variation process of road capacity. Moreover, the difference and reasons of road capacity varying have been further studied when the different lanes have been occupied in the process of accident treatment.

Research on Strategy Intelligent Control of Traffic Signal

In order to make the traffic flow smoothly through the intersection, to minimize the delay time, must ensure that the control decision of the traffic signal is real-time and accuracy. Aiming at the existing problems of the traditional timing control method, analysis of traffic signal control parameters, performance indicators, put forward the fuzzy inference is applied to the traffic signal control system, puts forward an intelligent traffic signal control system based on fuzzy control; the vehicle queue length, inlet flow rate, green extension as the control parameters and simulation the results show that the proposed control method can effectively improve the traffic congestion, improve the vehicle capacity.

Intersection Group Dynamic Subdivision and Coordination at Intraregional Boundaries in Sudden Disaster

This paper aims at the traffic flow agglomeration effect characteristics and rapid evacuation requirement in sudden disaster; operation time of intraregional boundaries traffic signal coordination was presented firstly. Then intraregional boundaries intersection group dynamic subdivision and consolidation method based on relative similarity degree and similarity coefficient of adjacent intersections was put forward. As to make the traffic control strategy adapt to traffic condition of different intraregional boundaries intersection groups, this paper proposes an intraregional boundaries traffic signal coordination and optimization technology based on organic computing theory. Finally, this paper uses Delphi 7.0, MapX, and Oracle developing a software package, combined with Paramics V6 Simulator to validate the methods of this paper. The result shows that it can obviously improve disaster affected regional traffic signal control efficiency which reduces average traffic delay by 30–35%, decreases vehicle queue by more than 20% and reduces evacuation time more than 13.06%.

Global Optimization for Transport Network Expansion and Signal Setting

This paper proposes a model to address an urban transport planning problem involving combined network design and signal setting in a saturated network. Conventional transport planning models usually deal with the network design problem and signal setting problem separately. However, the fact that network capacity design and capacity allocation determined by network signal setting combine to govern the transport network performance requires the optimal transport planning to consider the two problems simultaneously. In this study, a combined network capacity expansion and signal setting model with consideration of vehicle queuing on approaching legs of intersection is developed to consider their mutual interactions so that best transport network performance can be guaranteed. We formulate the model as a bilevel program and design an approximated global optimization solution method based on mixed-integer linearization approach to solve the problem, which is inherently nnonlinear and nonconvex. Numerical experiments are conducted to demonstrate the model application and the efficiency of solution algorithm.

Airport Curbside and Parking Area Operations at BIA – Analysis of User Behavior

Airport curbside, where travelers and their baggage enter and exit the terminal, and the designated parking area are important components in airport land-side facilities. Passengers expect safe and efficient roadway operations even as volumes increase, but the design and capacity of .the curbside are often constrained by the terminal building and the proximity of on-airport land-side infrastructure. The operating characteristics of airport terminal curbside differ significantly from those of most other roadways due to several reasons such as vehicle dwell time, maneuver vehicles to and from adjacent lane, variation in demand etc. The capacity of a curbside roadway is defined both by the number of vehicles that can be accommodated while stopping to pick up or drop off passengers and the number that can be accommodated while traveling past the curbside in the through lanes. Therefore a study of operations at curbside and parking area is important to identify issues related to existing and future demand levels. The main focus of the paper is on the evaluation of vehicle operations and passenger behavior at the BIA terminal access roadway, weaving segment, arrival and departure curbside roadways and terminal car park. Analysis of vehicular traffic, travel mode choices, and curbside roadway vehicle queues, vehicle dwelling times, passenger occupancy time at curbs and passenger processing and walking times will provide useful information for developing plans for operational improvements as well as for future expansions. Using the available data, the demand and the capacity at these facilities are evaluated to estimate the existing level of service. In addition, measures were identified to improve the operational efficiency of these facilities and design improvements are proposed to ensure good operational efficiency for the forecast future demand. ENGINEER, Vol. 47, No. 04, pp. 43-51, 2014

City Occupancy and Road Capacity Model

In this paper, we study the impact of city driveway occupancy on the urban road traffic capacity. Through the analysis of the scene of an accident case, we gained the vehicle statistics within a cross section in unit time and then did calculation and simulation. The work is concluded as a reasonable model of vehicle queue relationship evaluation.First, on the base of the definition of traffic capacity, statistics of the cars in the cross section before the accident, during the accident and after the accident have been respectively acquired in unit time (1 min). Then we employ Matlab to do the interpolation fitting, drawing the change of actual capacity of the road from the beginning time of an accident to the time when traffic resumes. The work comes to a conclusion that the change of the capacity at the cross section has a pattern of periodic fluctuation.

OPTIMALISASI KAPASITAS GERBANG TOL SEMANGGI I DAN SEMANGGI II TERHADAP PANJANG ANTRIAN KENDARAAN

Research on optimization of the capacity of toll gate semanggi 1 and 2 to long queues of vehicles is done by the queue theory approach and the capacity of the toll gate. Calculation of additional substation on the optimal number of toll gate semanggi 1 and 2 uses multiserver queuing theory. To address the causes of the most dominant variable in the long queue of vehicles is done by statistical tests. Increasing the number of substations which is done must be adjusted by the number of long queues of vehicles that are allowed by the minister for state owned company is 5 vehicles. The research methodology used is to conduct a survey of service time, the volume of vehicular traffic, the caused of the long queues of vehicles and open-close timing of toll gate semanggi 1. Based on the analysis obtained by calculating the optimal number of substations, based on normal conditions, changes in payment mechanisms and arrangements open and close toll gates semanggi 1 variable causes the most dominant long queue which is dated within one month of the service time of the transaction, a large nominal payment to the substation as well as the date of service time in 1 month and non-normal behavior of users jointly affect the service time of transactions. The result is the calculation of the optimal number of substations based on the change in payment mechanism at toll gate semanggi 1 with 3 main substations, while the toll gate semanggi 2 with 4 main substations. The optimum number of substations based on normal conditions at toll gate semanggi 1 are 4 main substations, while the toll gate semanggi 2 are 2 main substations and 2 tandem substations, while the number of substations based on the optimal open-close system at toll gate semanggi 1, at toll gate clover 1 is 4 main substations, while at toll gate semanggi 2 by 4 main substations. The timing for the opening and closing of toll gate semanggi 1 is 11 minutes for closing time, and 49 minutes for every hour of time in the open condition.
 Key words: optimization, toll gate capacity, queuing vehicles

Jam formation with line changing at two tollgates on a highway

We present the stochastic model for queueing at two tollgates with line changing of vehicles to take into account fluctuating inflow and outflow. We study the jam formation and its transition in front of two tollgates on a highway. The line changing between two queues of vehicles has an important effect on the jam formation. The jams are classified into three kinds: (a) localized jam, (b) line-changing jam, and (c) growing jam. The jamming transitions among different jams occur at two stages with increasing inflow rate. At the first transition point, the jamming transition from the localized jam to the line-changing jam occurs. When the inflow rate is higher than the sum of outflow rates at two tollgates, two jams continue to grow and diverge with time. At the second transition point, the jamming transition from the line-changing jam to the growing jam occurs. The dependence of the transition points on the choice probability is clarified.

Methods for estimating vehicle queues at a marine terminal: A computational comparison

Abstract A long queue of vehicles at the gate of a marine terminal is a common traffic phenomenon in a port-city, which sometimes causes problems in urban traffic. In order to be able to solve this issue, we firstly need accurate models to estimate such a vehicle queue length. In this paper, we compare the existing methods in a case study, and evaluate their advantages and disadvantages. Particularly, we develop a simulation-based regression model, using the micro traffic simulation software PARAMIC. In simulation, it is found that the queue transient process follows a natural logarithm curve. Then, based on these curves, we develop a queue length estimation model. In the numerical experiment, the proposed model exhibits better estimation accuracy than the other existing methods

Context Aware Dynamic Traffic Signal Optimization

Conventional urban traffic control systems have been based on historical traffic data. Later advancements made use of detectors, which enabled the gathering of real time traffic data, in order to reorganize and calibrate traffic signalization programs. Further evolvement provided the ability to forecast traffic conditions, in order to develop traffic signalization programs and strategies precomputed and applied at the most appropriate time frame for the optimal control of the current traffic conditions. We, propose the next generation of traffic control systems based on principles of Artificial Intelligence and Context Awareness. Most of the existing algorithms use average waiting time or length of the queue to assess an algorithms performance. However, a low average waiting time may come at the cost of delaying other vehicles indefinitely. In our algorithm, besides the vehicle queue, we use fairness also as an important performance metric to assess an algorithms performance.

A Real-Time Transit Signal Priority Control Model Considering Stochastic Bus Arrival Time

Transit signal priority (TSP) strategy gives transit vehicles preferential treatments to move through an intersection with minimum delay. To produce a good TSP timing, advance planning with enough look-ahead time is the key. This,however, means added uncertainty about bus arrival time at stop bar. In this paper, we proposed a stochastic mixed-integer nonlinear program (SMINP) model as the core component of a real-time TSP control system. The model adopts a novel approach to capture the impacts of the priority operation to other traffic by using the deviations of the phase split times from the optimal background split times. In addition, the model explicitly accounts for the randomness of the bus' arrival time by considering the bus stop dwell time and the delay caused by standing vehicle queues. The SMINP is implemented in a simulation evaluation platform developed using a combination of a microscopic traffic simulator and a commercial optimization solver. Comparison analyses were performed to compare the proposed control model with the state-of-the-practice TSP system [i.e., ring-barrier controller (RBC)-TSP]. The results showed the SMINP has yielded asmuch as 30% improvement of bus delay compared with RBC-TSP in a single-bus case. In a multiple-bus case, SMINP handles the bus priority request much more effectively under congested traffic conditions.