Urban Platooning Combined with Dynamic Traffic Lights

The traffic light coordination is often considered as a measure to improve traffic speed reducing car emission per meter. Although the dynamic approach has been widely developed in theory and application, static approach can be still useful in many design problems. Often design is made by static approaches and is also verified with dynamic models. The static approach study, in this paper, starts from flow profiles of vehicle platoons departing from a traffic light. Several past studies have concerned on the definition of flow profiles and in this paper it considers the collecting data modeling using the approach of cyclic flow profiles (TRANSYT TRRL) who gives the arrival distribution of flow platoons as a function of the distance from the first intersection through a recurrent computing. So it can know the car number in late for the green phase at the second light and then decide to increase the second green time according to the access waiting time or, conversely, reduce the green...

is paper addresses the problem of studying the impacts of the strategic formation of platoons in automated mobility-ondemand (AMoD) systems in future cities. Forming platoons has the potential to improve traffic efficiency, resulting in reduced travel times and energy consumption. However, in the platoon formation phase, coordinating the vehicles at formation locations for forming a platoon may delay travelers. In order to assess these effects, an agent-based model has been developed to simulate an urban AMoD system in which vehicles travel between service points transporting passengers either forming or not forming platoons. A simulation study was performed on the road network of the city of e Hague, Netherlands, to assess the impact on traveling and energy usage by the strategic formation of platoons. Results show that forming platoons could save up to 9.6% of the system-wide energy consumption for the most efficient car model. However, this effect can vary significantly with the vehicle types and strategies used to form platoons. Findings suggest that, on average, forming platoons reduces the travel times for travelers even if they experience delays while waiting for a platoon to be formed. However, delays lead to longer travel times for the travelers with the platoon leaders, similar to what people experience while traveling in highly congested networks when platoon formation does not happen. Moreover, the platoon delay increases as the volume of AMoD requests decreases; in the case of an AMoD system serving only 20% of the commuter trips (by private cars in the case-study city), the average platoon delays experienced by these trips increase by 25%. We conclude that it is beneficial to form platoons to achieve energy and travel efficiency goals when the volume of AMoD requests is high.

Sensors

The advent of the autonomous car is paving the road to the realization of ideas that will help optimize traffic flows, increase safety and reduce fuel consumption, among other advantages. We present one proposal to bring together Virtual Traffics Lights (VTLs) and platooning in urban scenarios, leaning on vehicle-to-vehicle (V2V) communication protocols that turn intersections into virtual containers of data. Newly-introduced protocols for the combined management of VTLs and platoons are validated by simulation, comparing a range of routing protocols for the vehicular networks with the baseline given by common deployments of traditional traffic lights ruled by state-of-the-art policies. The simulation results show that the combination of VTLs and platoons can achieve significant reductions in travel times and fuel consumption, provided that proper algorithms are used to handle the V2V communications.

16th International IEEE Conference on Intelligent Transportation Systems (ITSC 2013), 2013

The major benefits of driving vehicles in controlled close formations such as platoons are that of increasing traffic fluidity and reducing air pollution. While Vehicle-toVehicle (V2V) communications is requisite for platooning stability, the existing radio communications technologies (e.g., the IEEE 802.11p) suffer from poor performance in highly dense road scenarios, which are exactly to be created by platooning. This paper studies the applicability of visible light communications (VLC) system for information exchange between the platoon members. A complete VLC model is built enabling precise calculations of Bit-Error-Rate (BER) affected by inter-vehicle distance, background noise, incidence angle and receiver electrical bandwidth. Based on our analytical model, the optical parameters suiting platooning application are defined. Finally, a SIMULINK model is developed to study the performances of a platooning longitudinal and lateral control, where VLC is used for V2V information exchange. Our study demonstrates the feasibility of VLC-based platooning control even in the presence of optical noise at significant levels and up to a certain road curvature.

Self-Organization: Applied Multi-Agent Systems, 2008

Transportation Research Board 88th …, 2009

Queues at controlled intersections play an important role in the performance of urban networks, as they are determinant of the delay that drivers experience, and the level of service of road networks. These queues have upper bounds, which, once exceeded, cause extra delays also to other links and other traffic streams. Often this effect is neglected in practice, or it is calculated as a deterministic phenomenon. In this paper we describe the queue length probabilities at each moment in time for closely-spaced pre-timed traffic lights, using a probabilistic approach. Special attention goes to the influence of the upstream signal settings on the downstream arrival pattern and the influence of the downstream queue, which can block the upstream intersection by exceeding the available space. Based on this model, a case study is used to illustrate the performance of bad coordination of signals. We show that if two signals are not well coordinated and if insufficient green is assigned to the downstream direction spillback will be likely to occur, causing extra delay in the system.

Arabian Journal for Science and Engineering, 2018

Vehicles generally move in the form of platoons after discharging from the stop line of signalized intersection. While moving toward the downstream signal, due to the interaction between moving vehicles, road geometry, traffic composition and their speed difference, platoons get dispersed. Dispersion of platoon influences signal coordination , arrival pattern, turning maneuver at upstream signal. Moreover, while designing the intersection under mixed traffic scenario, platoon dispersion is important to create a link between traffic signals. Therefore, the present study is taken up with the objective of estimating the platoon dispersion distance after crossing the stop line. A model is developed based on the simulated data sets. VISSIM, a micro-simulation software, is used to replicate the field traffic conditions. To ensure the applicability of the model in the existing mixed traffic conditions, two different methods were used. Firstly, data were collected from two sites and used for validating the performance of the model. The results indicated a good match (maximum 9% error) between the field-observed and model-estimated platoon dispersion distance. Secondly, the traffic scenario alike the two study sites was created in VISSIM and the simulated and field-observed data sets were compared to check how accurately VISSIM can replicate the existing mixed traffic conditions. It is observed that VISSIM had replicated the field conditions with a maximum error of 10%. Therefore, the output of the study indicates that the proposed model may be used to estimate the platoon dispersion distance with reasonably high accuracy under mixed traffic conditions.

… and Computers in …, 2009

The paper describes an optimization procedure to synchronize traffic signals along an urban road artery. The solution procedure applies first a genetic algorithm and then a hill climbing algorithm for local adjustments. The fitness function is evaluated by means of a traffic model that simulates platoon progression along the links, their combination and possible queuing at nodes. The potential benefits of the synchronization procedure have been assessed by simulating a real urban artery through the micro-simulation model Transmodeler.

Journal of Computational Science, 2020

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International Journal of Networked and Distributed Computing, 2020

The increase in vehicle numbers has resulted in the growth of traffic jams in cities and highways, thereby raising various issues on fuel consumption, environmental pollution, and traffic safety [1]. Platooning is an Intelligent Transport System (ITS) [2] application which has emerged as a promising solution for the traffic management in highways. The main idea of vehicle platooning suggests that a set of vehicles travel together while maintaining a small distance between each other. This can lead to an increase in traffic capacity and then an improved traffic management and a reduced travel time. Moreover, the comfort and the safety of passengers are enhanced since the scenarios of extreme acceleration or deceleration are eliminated and the platoon vehicles are considered as a single unit. Furthermore, the emission performance and the fuel economy are significantly improved. A vehicle platoon (also called "convoy") can be seen as a group of vehicles that travel in close coordination through a headway control mechanism. These vehicles maintain a short spacing between them and a relative velocity. The vehicle in the front position, called leader, represents the trajectory and velocity reference. It controls all the following vehicles in the platoon. Each vehicle of the platoon receives orders from the leader that may be communicated either directly or by the preceding vehicle. As platooning system is a critical system, safety is an important issue. However, safety is exposed to several challenges if the system does not achieve its goal without any disturbance. For instance, it is important to ensure that vehicles do not get too close and react within a certain time frame during emergencies. Then, platooning systems need to be validated to ensure a reliable behaviour. For that, it is necessary to clearly define validation strategies (formal verification, simulation, etc.) as this has already been used in critical fields like healthcare [3] and avionics [4]. That is why, we make emphasis in this paper on the works that deal with validation methods and techniques for platooning systems. 1.2. Related Surveys and Scope of the Paper There are several useful surveys which have been conducted to deal with some aspects related to platooning algorithms. In Kavathekar and Chen [5], the authors introduce several existing algorithms which focus on vehicle platooning. Besides, they detail some methodologies for obstacle detection and collision avoidance. Furthermore, they are interested in inter-vehicle communication techniques which allow vehicles to share some information such as the velocity, acceleration and detected obstacles. In the same context, the survey of Jia et al. [6] provides a valuable insight about platoon-based vehicular systems. The main issues related to these systems are analysed such as the platoon management and the communication inter-and intra-platoon. The study of Kulla et al. [7] presents a survey in which they introduce a classification of vehicular communication methods which aim to control vehicles. Moreover, the authors introduce the different platooning operations which can take place to enhance the driving efficiency and increase safety.