Optimization of Emergency Transportation Organization of Holiday Tourism Traffic

The purpose of the optimization of holiday traffic emergency traffic organization is to solve the problem of serious traffic jams in holiday scenic spots. Based on the prediction of traffic volume and traffic mode division in the future years of the scenic spot, the traffic accident route is analyzed to provide theoretical support for the emergency traffic organization and planning of the scenic spot. This article takes the Shijiazhuang Jinta Bay scenic area as the research object, based on the traffic volume of the Jinta Bay tourist scenic area from 2009 to 2016, analyzes the traffic environment of the scenic area, predicts the traffic demand, and builds a one-way traffic organization double-layer optimization model. The simulated annealing algorithm is used to solve the model, an emergency transportation organization optimization plan is formulated, and the feasibility of the plan is verified through VISSIM simulation. The results of the study show that the one-way traffic organization method reduces the average vehicle delay by 32.2% and the average queue length by 14.5%. The one-way traffic organization based on branch diversion can more effectively solve the main road jamming and congestion caused by traffic accidents, prevent the occurrence of secondary accidents, and reduce the economic losses of scenic area managers. At the same time, the purpose of ensuring the tourist quality of tourists and the economic interests of scenic spot management departments is ensured.

Simulation-Based Evaluation of Variation in Left-Turn Paths in the Coordinated Intersection Management

Coordinated intersection management (CIM) has gained more attention with the advance of connected and autonomous vehicle technology. The optimization of passing schedules and conflict separation between conflicting vehicles are usually conducted based on the predefined travelling paths through the intersection area in the CIM. In real-world implementation, however, the diversity of turn paths exists due to multiple factors such as various vehicle sizes and automation control algorithms. The aim of this paper is to investigate how the variation in left-turn paths affects the feasibility and viability of optimal passing schedules, as well as the safety and efficiency of intersection operation. To do this, we start with identifying six typical left-turn paths to represent the variation. A scenario-based simulation is first conducted by using each of the paths as the nominal path. The optimal schedules and the corresponding alternative schedules are generated to calculate indicators for nominal performance, average performance, and robustness. The best path is selected in terms of schedule optimality and robustness. With schedules obtained by solving CIM models using the selected path, the left-turning CAVs are assumed to travel along one of the six paths randomly to simulate the path divergence. A surrogate safety measure, PET, is utilized to assess the safety of the intersection under CIM. The theoretical PET with the nominal path and the actual PET with the random path are calculated for each conflict event. Comparisons of two PET sets show the increase in conflict risk and vehicle delay. The conclusion can be drawn that the variation in left-turn paths causes the decline in safety level and travelling efficiency and should be considered in the CIM model to ensure safe and efficient implementation in the intersection.

Vehicle Delay Model Applied to Dynamic and Static Traffic Impact Analysis of Large Parking Lots

With the surge of motor vehicle ownership and land intensification, plenty of large parking lots emerge as the times demand. Although it solves the problem of insufficient parking spaces, it intensifies the interaction between dynamic and static traffic. This paper presented an impact assessment method for the interaction of dynamic and static traffic flow in parking lots. Firstly, the average vehicle delay was selected as the evaluation index. The delay effect caused by the interaction of dynamic and static traffic flow was determined according to the driving path of vehicles. Then, the average vehicle delay models of arrival vehicles, departure vehicles, and road vehicles in the parking lot were established. Finally, for the parameters difficult to determine directly in the delay model, this paper proposed a method to calibrate the model parameters by using the simulation experimental data on the VISSIM platform. The results showed that the errors of the three models are within the controllable range, and the delay model parameters had high reliability and feasibility. The delay models can provide a quantitative basis for the parking lot management department to formulate regulation strategies and realize more refined information guidance and navigation in the parking lot.

Research on a Task Offloading Strategy for the Internet of Vehicles Based on Reinforcement Learning

Today, vehicles are increasingly being connected to the Internet of Things, which enables them to obtain high-quality services. However, the numerous vehicular applications and time-varying network status make it challenging for onboard terminals to achieve efficient computing. Therefore, based on a three-stage model of local-edge clouds and reinforcement learning, we propose a task offloading algorithm for the Internet of Vehicles (IoV). First, we establish communication methods between vehicles and their cost functions. In addition, according to the real-time state of vehicles, we analyze their computing requirements and the price function. Finally, we propose an experience-driven offloading strategy based on multi-agent reinforcement learning. The simulation results show that the algorithm increases the probability of success for the task and achieves a balance between the task vehicle delay, expenditure, task vehicle utility and service vehicle utility under various constraints.

Vehicle Delay Estimation at Signalized Intersections Using Machine Learning Algorithms

Accurate determination of average vehicle delays is significant for effective management of a signalized intersection. The vehicle delays can be determined by field studies, however, this approach is costly and time consuming. Analytical methods which are commonly utilized to estimate delay cannot generate accurate estimates, especially in oversaturated traffic flow conditions. Delay estimation models based on artificial intelligence have been presented in the literature in recent years to estimate the delay more accurately. However, the number of artificial/heuristic intelligence techniques utilized for vehicle delay estimation is limited in the literature. In this study, estimation models are developed using four different machine learning methods—support vector regression (SVR), random forest (RF), k nearest neighbor (kNN), and extreme gradient boosting (XGBoost)—that have not previously been applied in the literature for vehicle delay estimation at signalized intersections. The models were tested with data collected from 12 signalized intersections located in Ankara, the capital of Turkey, and the performance of the models was revealed. The models were furthermore compared with successful delay models from the literature. The developed models, in particular the RF and XGBoost models, showed high performance in estimating the delay at signalized intersections under different traffic conditions. The results indicate that the delay estimation models based on the RF and XGBoost techniques can significantly contribute to both the literature and practice.

Rhythmic Control of Automated Traffic—Part I: Concept and Properties at Isolated Intersections

Leveraging the accuracy and consistency of vehicle motion control enabled by the connected and automated vehicle technology, we propose the rhythmic control (RC) scheme that allows vehicles to pass through an intersection in a conflict-free manner with a preset rhythm. The rhythm enables vehicles to proceed at a constant speed without any stop. The RC is capable of breaking the limitation that right-of-way can only be allocated to nonconflicting movements at a time. It significantly improves the performance of intersection control for automated traffic. Moreover, the RC with a predetermined rhythm does not require intensive computational efforts to dynamically control vehicles, which may possibly lead to frequent accelerations or decelerations. Assuming stationary vehicle arrivals, we conduct a theoretical investigation to show that RC can considerably increase intersection capacity and reduce vehicle delay. Finally, the performance of RC is tested in the simulations with both stationary and nonstationary vehicle arrivals at both symmetric and asymmetric intersections.

Analysis of traffic density onthree-way junction in Jalan Sukabangun 2 using Vissim simulations model

VISSIM is a Simulations model which means a city traffic simulation model. VISSIM is a simulation software used by professionals to create simulations from dynamic traffic scenarios before making real plans. This research was conducted to determine how traffic performance and traffic performance optimization at the junctions between the existing conditions and the Vissim program caused by congestion. An effective method for overcoming non-jammed junctions can be made using the VISSIM method. This study was conducted at THREE-WAY JUNCTION in Jl. Sukabangun 2 (South) - Jl. R.A Abusamah (West) - Jl. Sukabangun 2 (Utara) - Jl. BeringinSukabangun 2 (East). In this study, three variations were used, namely the traffic light method, the method of forbidden turning right, and the method of dividing the road and turning signs. The results of PTV Vissim simulation showed that the traffic light method has a quite high queue length, namely 79m compared to the existing condition of 63m, for the vehicle delay in this method is 98.954s. On the method of forbidden turning right from the direction of Jl. BeringinSukabangun 2 (East) has a low queue length of 0.287m compared to the existing condition of 63m. The vehicle delay in this method is 13.307s. The method of dividing the road and turning signs, the queue length is quite low at 1.147m compared to the existing condition of 63m. The vehicle delay in this method is 30,169s. The results of the simulation revealed that the most effective method at THREE-WAY JUNCTION in jalanSukabangun 2 is method of forbidden turning right, dividing the roads and turning signs.

Sensitivity of Rodel Roundabout Delay Estimates to Input Parameters

Modern roundabouts are developed to increase the traffic capacity and decrease the traffic delay. They are popular around the world and are becoming common in Canada and the United States. A great design of a roundabout is to achieve the minimum delay. According to the research papers regarding the delay at roundabouts, it is expected the vehicle delay, the stop ratio at various traffic volumes, and the level of saturation of roundabouts are smaller than the amount of similar parameters on un-signalized intersections. The purpose of this thesis is clarification and measurement of the geometric parameters through the RODEL software to depict their influence on the sensitivity of roundabout delay. This study has been done through creation and analysis of numerous tables and graphs for various traffic volumes and peak periods. Furthermore, the required accuracy of each parameter in estimating delay of a planned roundabout is determined. The outcome of this analysis indicates the effects of the geometric parameters on the roundabout delay. While the Half Width, Entry Width, and Flare Length have the greatest influence on the delay, the Entry Radius, Entry Angle (PHI), and Inscribed Circle Diameter have the least influence.

Sensitivity of Rodel Roundabout Delay Estimates to Input Parameters

Modern roundabouts are developed to increase the traffic capacity and decrease the traffic delay. They are popular around the world and are becoming common in Canada and the United States. A great design of a roundabout is to achieve the minimum delay. According to the research papers regarding the delay at roundabouts, it is expected the vehicle delay, the stop ratio at various traffic volumes, and the level of saturation of roundabouts are smaller than the amount of similar parameters on un-signalized intersections. The purpose of this thesis is clarification and measurement of the geometric parameters through the RODEL software to depict their influence on the sensitivity of roundabout delay. This study has been done through creation and analysis of numerous tables and graphs for various traffic volumes and peak periods. Furthermore, the required accuracy of each parameter in estimating delay of a planned roundabout is determined. The outcome of this analysis indicates the effects of the geometric parameters on the roundabout delay. While the Half Width, Entry Width, and Flare Length have the greatest influence on the delay, the Entry Radius, Entry Angle (PHI), and Inscribed Circle Diameter have the least influence.

Urban Traffic Signals Timing at Four-Phase Signalized Intersection Based on Optimized Two-Stage Fuzzy Control Scheme

This paper proposes a signal timing scheme through a two-stage fuzzy logic controller. The controller first determines the signal phase and then adjusts the green time. At the first stage, the adaptive membership function of vehicle arrival rate is improved to adapt to the changing traffic flow. In addition to arrival rate and queue vehicles, a specific phase order rule is considered to avoid disordered phase selection in fuzzy control. At the second stage, the green time detection module decides whether to extend the current green time or switch phases every few seconds and the vehicle arrival rate is not required as the input to controller in real-time detection. Differential evolution algorithm with low space complexity and fast convergence is applied to optimize the fuzzy rules for avoiding artificial uncertainty. Simulation experiments are designed to compare traditional fuzzy controller, fixed-time controller, and fuzzy controller without flow prediction. Results show that the current proposed method in this paper can reduce vehicle delay significantly.