Download or read book Integrating Adaptive Queue responsive Traffic Signal Control with Dynamic Traffic Assignment written by Lee-Fang Chow and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT (con't) : Improvements to DTA methods include formulating the dynamic user-optimal route choice model as a variational inequality (VI) model, calculating the expected travel time on each link using a simulation model, applying a relaxation algorithm to produce an equivalent optimization formulation of the VI model, and developing a solution algorithm which can be implemented using existing traffic software. There is not much hope for developing exact solution algorithms to solve these two models simultaneously because of the computational complexity of the non-linear programs. Therefore, a heuristic procedure involving an iterative optimization assignment is used to solve the combined models. A computerized procedure was developed to implement the solution procedures and a numerical example of a traffic network was prepared to test the program. An accepted traffic simulation model, CORSIM 5.1, was used to validate the results for both static and dynamic optimizations. The test results showed that dynamic traffic assignment with adaptive traffic-responsive signal settings reduced the network-wide delays by nearly 15%.

Download or read book Integration of Dynamic Traffic Assignment with Real Time Traffic Adaptive Control written by Nathan H. Gartner and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integration of Adaptive Traffic Control and Traffic Assignment written by Alexander Paz Cruz and published by . This book was released on 2002 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimal Integrated Dynamic Traffic Assignment and Signal Control for Evacuation of Large Traffic Networks with Varying Threat Levels written by Neema Nassir and published by . This book was released on 2013 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research contributes to the state of the art and state of the practice in solving a very important and computationally challenging problem in the areas of urban transportation systems, operations research, disaster management, and public policy. Being a very active topic of research during the past few decades, the problem of developing an efficient and practical strategy for evacuation of real-sized urban traffic networks in case of disasters from different causes, quickly enough to be employed in immediate disaster management scenarios, has been identified as one of the most challenging and yet vital problems by many researchers. More specifically, this research develops fast methods to find the optimal integrated strategy for traffic routing and traffic signal control to evacuate real-sized urban networks in the most efficient manner. In this research a solution framework is proposed, developed and tested which is capable of solving these problems in very short computational time. An efficient relaxation-based decomposition method is proposed, implemented for two evacuation integrated routing and signal control model formulations, proven to be optimal for both formulations, and verified to reduce the computational complexity of the optimal integrated routing and signal control problem. The efficiency of the proposed decomposition method is gained by reducing the integrated optimal routing and signal control problem into a relaxed optimal routing problem. This has been achieved through an insight into intersection flows in the optimal routing solution: in at least one of the optimal solutions of the routing problem, each street during each time interval only carries vehicles in at most one direction. This property, being essential to the proposed decomposition method, is called "unidirectionality" in this dissertation. The conditions under which this property exists in the optimal evacuation routing solution are identified, and the existence of unidirectionality is proven for: (1) the common Single-Destination System-Optimal Dynamic Traffic Assignment (SD-SODTA) problem, with the objective to minimize the total time spent in the threat area; and, (2) for the single-destination evacuation problem with varying threat levels, with traffic models that have no spatial queue propagation. The proposed decomposition method has been implemented in compliance with two widely-accepted traffic flow models, the Cell Transmission Model (CTM) and the Point Queue (PQ) model. In each case, the decomposition method finds the optimal solution for the integrated routing and signal control problem. Both traffic models have been coded and applied to a realistic real-size evacuation scenario with promising results. One important feature that is explored is the incorporation of evacuation safety aspects in the optimization model. An index of the threat level is associated with each link that reflects the adverse effects of traveling in a given threat zone on the safety and health of evacuees during the process of evacuation. The optimization problem is then formulated to minimize the total exposure of evacuees to the threat. A hypothetical large-scale chlorine gas spill in a high populated urban area (downtown Tucson, Arizona) has been modeled for testing the evacuation models where the network has varying threat levels. In addition to the proposed decomposition method, an efficient network-flow solution algorithm is also proposed to find the optimal routing of traffic in networks with several threat zones, where the threat levels may be non-uniform across different zones. The proposed method can be categorized in the class of "negative cycle canceling" algorithms for solving minimum cost flow problems. The unique feature in the proposed algorithm is introducing a multi-source shortest path calculation which enables the efficient detection and cancellation of negative cycles. The proposed method is proven to find the optimal solution, and it is also applied to and verified for a mid-size test network scenario.

Download or read book Integrated Anticipatory Control of Road Networks written by Henk Taale and published by . This book was released on 2008 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Feedback Control Theory for Dynamic Traffic Assignment written by Pushkin Kachroo and published by Springer. This book was released on 2018-05-16 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book develops a methodology for designing feedback control laws for dynamic traffic assignment (DTA) exploiting the introduction of new sensing and information-dissemination technologies to facilitate the introduction of real-time traffic management in intelligent transportation systems. Three methods of modeling the traffic system are discussed: partial differential equations representing a distributed-parameter setting; continuous-time ordinary differential equations (ODEs) representing a continuous-time lumped-parameter setting; and discreet-time ODEs representing a discrete-time lumped-parameter setting. Feedback control formulations for reaching road-user-equilibrium are presented for each setting and advantages and disadvantage of using each are addressed. The closed-loop methods described are proposed expressly to avoid the counter-productive shifting of bottlenecks from one route to another because of driver over-reaction to routing information. The second edition of Feedback Control Theory for Dynamic Traffic Assignment has been thoroughly updated with completely new chapters: a review of the DTA problem and emphasizing real-time-feedback-based problems; an up-to-date presentation of pertinent traffic-flow theory; and a treatment of the mathematical solution to the traffic dynamics. Techinques accounting for the importance of entropy are further new inclusions at various points in the text. Researchers working in traffic control will find the theoretical material presented a sound basis for further research; the continual reference to applications will help professionals working in highway administration and engineering with the increasingly important task of maintaining and smoothing traffic flow; the extensive use of end-of-chapter exercises will help the graduate student and those new to the field to extend their knowledge.

Download or read book Integrated Control of Mixed Traffic Networks Using Model Predictive Control written by Monique Berg and published by . This book was released on 2010 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integration of Predictive Routing Information with Dynamic Traffic Signal Control written by Richard Charles Staats and published by . This book was released on 1994 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamic Traffic Routing and Adaptive Signal Control in a Connected Vehicles Environment written by Huajun Chai and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation aims to study effective and efficient ways for both travelers and transportation authorities to consider the actions of the other side when they make their corresponding travel or management decisions, such that certain common goals, such as mitigating congestion, reducing cost in travel expenses and improving the overall reliability of the transportation system can be achieved. A novel dynamic traffic routing (DTR) with an adaptive signal control framework is developed to utilize the fast developing wireless communication technologies that makes V2X (Vehicle To Everything) possible. The hyper-path based dynamic traffic routing method takes stochasticity of link travel time into consideration, which ensures robust and reliable routing decisions. In addition, online travel time updating is incorporated into the DTR model. The online updating presented in this dissertation uses both historical information (a priori knowledge) and new information, thanks to the V2X system, to form a posteriori knowledge about the link travel time. Various distributed traffic signal control methods are proposed and tested with the DTR model to cope with the different levels of the traffic demand. The joint dynamic traffic routing and adaptive signal control model developed in this dissertation performs well in most cases. However, the underlying logic of DTR does not guarantee to prevent deadlock from happening. To address this issue, following the study of dynamic traffic routing and adaptive signal control, I formulate a deadlock avoidance model under dynamic user equilibrium with queue spillback. In the proposed model, travelers' route choice is governed by a simple "DLA (DeadLock Avoidance) Routing" rule which is proved to generate deadlock free routing result. Potential deadlocks during the optimization of the model are detected with an algorithm modified based on Floyd Warshall Algorithm. The algorithm then assigns a deadlock potential value to each potential deadlock. The model minimizes this potential, and meanwhile tries to maintain the total travel time in the network at a reasonably low level. Many transportation applications can potentially take advantage of the research results in this dissertation. We explored one interesting and important application scenario-the parking search problem in the final chapter of this dissertation.

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multi agent Look ahead Traffic adaptive Control written by Ronald Theodoor Katwijk and published by . This book was released on 2008 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Demand responsive Decentralized Urban Traffic Control written by Nathan H. Gartner and published by . This book was released on 1982 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Multimodal Traffic Signal Control written by Hesham Rakha and published by . This book was released on 2019 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptive Traffic Signal Control Using Deep Reinforcement Learning for Network Traffic Incidents written by Tianxin Li (M.S. in Engineering) and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic signal control is an essential aspect of urban mobility that significantly impacts the efficiency and safety of transportation networks. Traditional traffic signal control systems rely on fixed-time or actuated signal timings, which may not adapt to the dynamic traffic demands and congestion patterns. Therefore, researchers and practitioners have increasingly turned to reinforcement learning (RL) techniques as a promising approach to improve the performance of traffic signal control. This dissertation investigates the application of RL algorithms to traffic signal control, aiming to optimize traffic flow and reduce congestion. The study develops a simulation model of a signalized intersection and trains RL agents to learn how to adjust signal timings based on real-time traffic conditions. The RL agents are designed to learn from experience and adapt to changing traffic patterns, thereby improving the efficiency of traffic flow, even for scenarios in which traffic incidents occur in the network. In this dissertation, the potential benefits of using RL algorithms to optimize traffic signal control in scenarios with and without traffic incidents were explored. To achieve this, an incident generation module was developed using the open-source traffic signal performance simulation framework that relies on the SUMO software. This module includes emergency response vehicles to mimic the realistic impact of traffic incidents and generates incidents randomly in the network. By exposing the RL agent to this environment, it can learn from the experience and optimize traffic signal control to reduce system delay. The study began with a single intersection scenario, where the DQN algorithm was modeled to form the RL agent traffic signal controller. To improve the training process and model performance, experience replay and target network were implemented to solve the limitations of DQN. Hyperparameter tuning was conducted to find the best parameter combination for the training process, and the results showed that DQN outperformed other controllers in terms of the system-wise and intersection-wise queue distribution and vehicle delay. The study was then extended to a small corridor with 2 intersections and a grid network (2x2 intersection), and the incident generation module was used to expose the RL agent to different traffic scenarios. Again, hyperparameter tuning was conducted, and the DQN model outperformed other controllers in terms of reducing congestion and improving the system performance. The robustness of the DQN performance was also tested with different demands, and the microsimulation results showed that the DQN performance was consistent. Overall, this study highlights the potential of RL algorithms to optimize traffic signal control in scenarios with and without traffic incidents. The incident generation module developed in this study provides a realistic environment for the RL agent to learn and adapt, leading to improved system performance and reduced congestion. In addition, hyperparameter tuning is essential to lay down a solid foundation for the RL training process

Download or read book Adaptive Traffic Signal Control Using Approximate Dynamic Programming written by Chen Cai and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integration of Dynamic Traffic Control and Assignment written by Owen Jianwen Chen and published by . This book was released on 1998 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptive Traffic Control Systems written by Aleksandar Stevanovic and published by Transportation Research Board National Research. This book was released on 2010 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 403: Adaptive Traffic Control Systems: Domestic and Foreign State of Practice explores the state of practice of adaptive traffic control systems (ATCSs), also known as real-time traffic control systems, which adjust, in real time, signal timings based on traffic conditions, demand, and system capacity --