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Traffic Signals Control with Adaptive Fuzzy Controller in Urban Road Network 被引量:1
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作者 李艳 樊晓平 《Journal of Donghua University(English Edition)》 EI CAS 2008年第6期710-717,共8页
An adaptive fuzzy logic controller (AFC) is presented for the signal control of the urban traffic network. The AFC is composed of the signal control system-oriented control level and the signal controller-oriented fuz... An adaptive fuzzy logic controller (AFC) is presented for the signal control of the urban traffic network. The AFC is composed of the signal control system-oriented control level and the signal controller-oriented fuzzy rules regulation level. The control level decides the signal timings in an intersection with a fuzzy logic controller. The regulation level optimizes the fuzzy rules by the Adaptive Rule Module in AFC according to both the system performance index in current control period and the traffic flows in the last one. Consequently the system performances are improved. A weight coefficient controller (WCC) is also developed to describe the interactions of traffic flow among the adjacent intersections. So the AFC combined with the WCC can be applied in a road network for signal timings. Simulations of the AFC on a real traffic scenario have been conducted. Simulation results indicate that the adaptive controller for traffic control shows better performance than the actuated one. 展开更多
关键词 traffic signal control urban road network fuzzy logic adaptive algorithm traffic interaction
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A Data-Driven Intersection Geometry Mapping Technique to Enhance the Scalability of Trajectory-Based Traffic Signal Performance Measures
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作者 Enrique D. Saldivar-Carranza Darcy M. Bullock 《Journal of Transportation Technologies》 2023年第3期443-464,共22页
Connected vehicle (CV) trajectory data provides practitioners with opportunities to assess traffic signal performance with no investment in detection or communication infrastructure. With over 500 billion trajectory r... Connected vehicle (CV) trajectory data provides practitioners with opportunities to assess traffic signal performance with no investment in detection or communication infrastructure. With over 500 billion trajectory records generated each month in the United States, operations can be evaluated virtually at any of the over 400,000 traffic signals in the nation. The manual intersection mapping required to generate accurate movement-level trajectory-based performance estimations is the most time-consuming aspect of using CV data to evaluate traffic signal operations. Various studies have utilized vehicle location data to update and create maps;however, most proposed mapping techniques focus on the identification of roadway characteristics that facilitate vehicle navigation and not on the scaling of traffic signal performance measures. This paper presents a technique that uses commercial CV trajectory and open-source OpenStreetMap (OSM) data to automatically map intersection centers and approach areas of interest to estimate signal performance. OSM traffic signal tags are processed to obtain intersection centers. CV data is then used to extract intersection geometry characteristics surrounding the intersection. To demonstrate the proposed technique, intersection geometry is mapped at 500 locations from which trajectory-based traffic signal performance measures are estimated. The results are compared to those obtained from manual geometry definitions. Statistical tests found that at a 99% confidence level, upstream-focused performance estimations are strongly correlated between both methodologies. The presented technique will aid agencies in scaling traffic signal assessment as it significantly reduces the amount of manual labor required. 展开更多
关键词 Connected Vehicle TRAJECTORY traffic signal Performance Map GEOMETRY
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An integrated and cooperative architecture for multi-intersection traffic signal control
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作者 Qiang Wu Jianqing Wu +3 位作者 Bojian Kang Bo Du Jun Shen Adriana Simona Mihăiţă 《Digital Transportation and Safety》 2023年第2期150-163,共14页
Traffic signal control(TSC)systems are one essential component in intelligent transport systems.However,relevant studies are usually independent of the urban traffic simulation environment,collaborative TSC algorithms... Traffic signal control(TSC)systems are one essential component in intelligent transport systems.However,relevant studies are usually independent of the urban traffic simulation environment,collaborative TSC algorithms and traffic signal communication.In this paper,we propose(1)an integrated and cooperative Internet-of-Things architecture,namely General City Traffic Computing System(GCTCS),which simultaneously leverages an urban traffic simulation environment,TSC algorithms,and traffic signal communication;and(2)a general multi-agent reinforcement learning algorithm,namely General-MARL,considering cooperation and communication between traffic lights for multi-intersection TSC.In experiments,we demonstrate that the integrated and cooperative architecture of GCTCS is much closer to the real-life traffic environment.The General-MARL increases the average movement speed of vehicles in traffic by 23.2%while decreases the network latency by 11.7%. 展开更多
关键词 Intelligent transport system traffic signal control traffic Deep learning
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Safety Performance Functions for Traffic Signals:Phasing and Geometry
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作者 Shane Turner 《Journal of Civil Engineering and Architecture》 2023年第4期199-213,共15页
A significant proportion of urban crashes,especially serious and fatal crashes,occur at traffic signals.Many of the black-spots in both Australia and New Zealand cities occur at high volume and/or high-speed traffic s... A significant proportion of urban crashes,especially serious and fatal crashes,occur at traffic signals.Many of the black-spots in both Australia and New Zealand cities occur at high volume and/or high-speed traffic signals.Given this,crash reduction studies often focus on the major signalised intersections.However,there is limited information that links the phasing configuration,degree of saturation and overall cycle time to crashes.While a number of analysis tools are available for assessing the efficiency of intersections,there are very few tools that can assist engineers in assessing the safety effects of intersection upgrades and new intersections.Safety performance functions have been developed to help quantify the safety impact of various traffic signal phasing configurations and level of intersection congestion at low and high-speed traffic signals in New Zealand and Australia.Data from 238 signalised intersection sites in Auckland,Wellington,Christchurch,Hamilton,Dunedin and Melbourne was used to develop crash prediction models for key crash-causing movements at traffic signals.Different variables(road features)effect each crash type.The models indicate that the safety of intersections can be improved by longer cycle times and longer lost inter-green times,especially all-red time,using fully protected right turns and by extending the length of right turn bays.The exception is at intersections with lots of pedestrians where shorter cycle times are preferred as pedestrian crashes increase with longer wait times.A number of factors have a negative impact on safety including,free left turns,more approach lanes,intersection arms operating near or over capacity in peak periods and higher speed limits. 展开更多
关键词 Crash/Accident prediction models generalized linear models traffic signal layout and phasing pedestrian safety and safety performance functions
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NSGA-Ⅱ based traffic signal control optimization algorithm for over-saturated intersection group 被引量:6
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作者 李岩 过秀成 +1 位作者 陶思然 杨洁 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期211-216,共6页
In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) based traffic signal control optimization algorithm is prop... In order to improve the efficiency of traffic signal control for an over-saturated intersection group, a nondominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) based traffic signal control optimization algorithm is proposed. The throughput maximum and average queue ratio minimum for the critical route of the intersection group are selected as the optimization objectives of the traffic signal control for the over-saturated condition. The consequences of the efficiency between traffic signal timing plans generated by the proposed algorithm and a commonly utilized signal timing optimization software Synchro are compared in a VISSIM signal control application programming interfaces (SCAPI) simulation environment by using real filed observed traffic data. The simulation results indicate that the signal timing plan generated by the proposed algorithm is more efficient in managing oversaturated flows at intersection groups, and, thus, it has the capability of optimizing signal timing under the over-saturated conditions. 展开更多
关键词 traffic signal control optimization algorithm intersection group over-saturated status NSGA-H algorithm
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Fuzzy traffic signal control with DNA evolutionary algorithm 被引量:2
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作者 毕云蕊 路小波 +1 位作者 孙哲 曾唯理 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期207-210,共4页
In order to optimize the signal control system, this paper proposes a method to design an optimized fuzzy logic controller (FLC) with the DNA evolutionary algorithm. Inspired by the DNA molecular operation character... In order to optimize the signal control system, this paper proposes a method to design an optimized fuzzy logic controller (FLC) with the DNA evolutionary algorithm. Inspired by the DNA molecular operation characteristics, the DNA evolutionary algorithm modifies the corresponding genetic operators. Compared with the traditional genetic algorithm (GA), the DNA evolutionary algorithm can overcome weak local search capability and premature convergence. The parameters of membership functions are optimized by adopting the quaternary encoding method and performing corresponding DNA genetic operators. The relevant optimized parameters are combined with the FLC for single intersection traffic signal control. Simulation experiments shows the better performance of the FLC with the DNA evolutionary algorithm optimization. The experimental results demonstrate the efficiency of the nrotmsed method. 展开更多
关键词 DNA evolutionary algorithm genetic algorithm(GA) fuzzy control traffic signal control
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Traffic Signal Timing via Deep Reinforcement Learning 被引量:71
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作者 Li Li Yisheng Lv Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI 2016年第3期247-254,254+248-253,共8页
In this paper, we propose a set of algorithms to design signal timing plans via deep reinforcement learning. The core idea of this approach is to set up a deep neural network (DNN) to learn the Q-function of reinforce... In this paper, we propose a set of algorithms to design signal timing plans via deep reinforcement learning. The core idea of this approach is to set up a deep neural network (DNN) to learn the Q-function of reinforcement learning from the sampled traffic state/control inputs and the corresponding traffic system performance output. Based on the obtained DNN, we can find the appropriate signal timing policies by implicitly modeling the control actions and the change of system states. We explain the possible benefits and implementation tricks of this new approach. The relationships between this new approach and some existing approaches are also carefully discussed. © 2014 Chinese Association of Automation. 展开更多
关键词 ALGORITHMS Timing circuits traffic control traffic signals
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Joint optimization traffic signal control for an urban arterial road 被引量:3
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作者 LI Yin-fei CHEN Shu-ping 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第2期135-143,共9页
This paper considers the optimal traffic signal setting for an urban arterial road. By introducing the concepts of synchronization rate and non-synchronization degree, a mathematical model is constructed and an optimi... This paper considers the optimal traffic signal setting for an urban arterial road. By introducing the concepts of synchronization rate and non-synchronization degree, a mathematical model is constructed and an optimization problem is posed. Then, a new iterative algorithm is developed to solve this optimal traffic control signal setting problem. Convergence properties for this iterative algorithm are established. Finally, a numerical example is solved to illustrate the effectiveness of the method. 展开更多
关键词 urban traffic network INTERSECTION traffic signal setting synchronism OPTIMIZATION
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Connected Vehicle-Based Traffic Signal Coordination 被引量:4
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作者 Wan Li Xuegang Ban 《Engineering》 SCIE EI 2020年第12期1463-1472,共10页
This study presents a connected vehicles(CVs)-based traffic signal optimization framework for a coordinated arterial corridor.The signal optimization and coordination problem are first formulated in a centralized sche... This study presents a connected vehicles(CVs)-based traffic signal optimization framework for a coordinated arterial corridor.The signal optimization and coordination problem are first formulated in a centralized scheme as a mixed-integer nonlinear program(MINLP).The optimal phase durations and offsets are solved together by minimizing fuel consumption and travel time considering an individual vehicle’s trajectories.Due to the complexity of the model,we decompose the problem into two levels:an intersection level to optimize phase durations using dynamic programming(DP),and a corridor level to optimize the offsets of all intersections.In order to solve the two-level model,a prediction-based solution technique is developed.The proposed models are tested using traffic simulation under various scenarios.Compared with the traditional actuated signal timing and coordination plan,the signal timing plans generated by solving the MINLP and the two-level model can reasonably improve the signal control performance.When considering varies vehicle types under high demand levels,the proposed two-level model reduced the total system cost by 3.8%comparing to baseline actuated plan.MINLP reduced the system cost by 5.9%.It also suggested that coordination scheme was beneficial to corridors with relatively high demand levels.For intersections with major and minor street,coordination conducted for major street had little impacts on the vehicles at the minor street. 展开更多
关键词 Connected vehicles traffic signal coordination Dynamic programming Two-level optimization Mixed-integer nonlinear program
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Tri-level programming model for combined urban traffic signal control and traffic flow guidance 被引量:1
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作者 SUN Zhi-yuan LU Hua-pu QU Wen-cong 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2443-2452,共10页
In order to balance the temporal-spatial distribution of urban traffic flow, a model is established for combined urban traffic signal control and traffic flow guidance. With consideration of the wide use of fixed sign... In order to balance the temporal-spatial distribution of urban traffic flow, a model is established for combined urban traffic signal control and traffic flow guidance. With consideration of the wide use of fixed signal control at intersections, traffic assignment under traffic flow guidance, and dynamic characteristics of urban traffic management, a tri-level programming model is presented. To reflect the impact of intersection delay on traffic assignment, the lower level model is set as a modified user equilibrium model. The middle level model, which contains several definitional constraints for different phase modes, is built for the traffic signal control optimization. To solve the problem of tide lane management, the upper level model is built up based on nonlinear 0-1 integer programming. A heuristic iterative optimization algorithm(HIOA) is set up to solve the tri-level programming model. The lower level model is solved by method of successive averages(MSA), the middle level model is solved by non-dominated sorting genetic algorithm II(NSGA II), and the upper level model is solved by genetic algorithm(GA). A case study is raised to show the efficiency and applicability of the proposed modelling and computing method. 展开更多
关键词 traffic engineering traffic signal control traffic flow guidance tri-level programming model
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Longitudinal Performance Assessment of Traffic Signal System Impacted by Long-Term Interstate Construction Diversion Using Connected Vehicle Data 被引量:6
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作者 Enrique D. Saldivar-Carranza Margaret Hunter +2 位作者 Howell Li Jijo Mathew Darcy M. Bullock 《Journal of Transportation Technologies》 2021年第4期644-659,共16页
Local arterials can be significantly impacted by diversions from adjacent work zones. These diversions often occur on unofficial detour routes due to guidance received on personal navigation devices. Often, these rout... Local arterials can be significantly impacted by diversions from adjacent work zones. These diversions often occur on unofficial detour routes due to guidance received on personal navigation devices. Often, these routes do not have sufficien<span style="font-family:Verdana;">t sensing or communication equipment to obtain infrastructure-based tra</span><span style="font-family:Verdana;">ffic signal performance measures, so other data sources are required to identify locations being significantly affected by diversions. This paper examines the network impact caused by the start of an 18-month closure of the I-65/70 interchange (North Split), which usually serves approximately 214,000 vehicles per day in Indianapolis, IN. In anticipation of some proportion of the public diverting from official detour routes to local streets, a connected vehicle monitoring program was established to provide daily performances measures for over 100 intersections in the area without the need for vehicle sensing equipment. This study reports on 13 of the most impacted signals on an alternative arterial to identify locations and time of day where operations are most degraded, so that decision makers have quantitative information to make informed adjustments to the system. Individual vehicle movements at the studied locations are analyzed to estimate changes in volume, split failures, downstream blockage, arrivals on green, and travel times. Over 130,000 trajectories were analyzed in an 11-week period. Weekly afternoon peak period volumes increased by approximately 455%, split failures increased 3%, downstream blockage increased 10%, arrivals on green decreased 16%, and travel time increase 74%. The analysis performed in this paper will serve as a framework for any agency that wants to assess traffic signal performance at hundreds of locations with little or no existing sensing or communication infrastructure to prioritize tactical retiming and/or longer-term infrastructure investments.</span> 展开更多
关键词 traffic signal Performance Measures Connected Vehicle Longitudinal Study Big Data
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Forecast of Air Traffic Controller Demand Based on SVR and Parameter Optimization 被引量:2
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作者 ZHANG Yali LI Shan ZHANG Honghai 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2021年第6期959-966,共8页
As the main body of air traffic control safety,the air traffic controller is an important part of the whole air traffic control system. According to the relevant data of civil aviation over the years,a mapping model b... As the main body of air traffic control safety,the air traffic controller is an important part of the whole air traffic control system. According to the relevant data of civil aviation over the years,a mapping model between flight support sorties and air traffic controller demand is constructed by using the prediction algorithm of support vector regression(SVR) based on grid search and cross-validation. Then the model predicts the demand for air traffic controllers in seven regions. Additionally,according to the employment data of civil aviation universities,the future training scale of air traffic controller is predicted. The forecast results show that the average relative error of the number of controllers predicted by the algorithm is 1.73%,and the prediction accuracy is higher than traditional regression algorithms. Under the influence of the epidemic,the demand for air traffic controllers will decrease in the short term,but with the control of the epidemic,the demand of air traffic controllers will return to the pre-epidemic level and gradually increase. It is expected that the controller increment will be about 816 by 2028. The forecast results of the demand for air traffic controllers provide a theoretical basis for the introduction and training of medium and long-term air traffic controllers,and also provide method guidance and decision support for the establishment of professional reserve and dynamic control mechanism in the air traffic control system. 展开更多
关键词 air traffic controller demand forecast support vector regression(SVR) grid search cross-validation
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Adaptive controller design based on input-output signal selection for voltage source converter high voltage direct current systems to improve power system stability 被引量:2
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作者 Abdolkhalegh Hamidi Jamal Beiza +1 位作者 Ebrahim Babaei Sohrab Khanmohammadi 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2254-2267,共14页
An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is w... An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance. 展开更多
关键词 input-output signal selection online adaptive damping controller nonlinear high voltage direct current power systemstability
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Cell transmission model based traffic signal timing in oversaturated conditions 被引量:1
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作者 王屏 L. S. Jones +1 位作者 杨群 S. Gurupackiam 《Journal of Central South University》 SCIE EI CAS 2013年第4期1129-1136,共8页
In order to investigate enhancements to cell transmission model (CTM) as a tool for traffic signal timing in oversaturated conditions, randomly distributed saturation flow rates and arrival rates were used instead of ... In order to investigate enhancements to cell transmission model (CTM) as a tool for traffic signal timing in oversaturated conditions, randomly distributed saturation flow rates and arrival rates were used instead of constant values to simulate traffic flow movement, estimate the average delay of the network and search for an optimal traffic signal timing plan. A case study was given to demonstrate that the proposed methodology can capture unique phenomena in oversaturated conditions such as forward wave, spillback and lane entrance blockage. The results show that CTM underestimates travel time by 25% when compared to Simtraffic, while the enhanced CTM underestimates by only 3%. A second case study shows that a dynamic signal timing plan is superior to a fixed signal timing plan in the term of average delay. 展开更多
关键词 oversaturated flow conditional cell transmission model traffic signal timing spillback BLOCKAGE
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FL-FN-MOGA Based Traffic Signal Control
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作者 Wei Wu & Zhang Yi Department of Automation, Tsinghua University, Beijing 100084, P. R. China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第3期14-23,共10页
In this paper, a traffic signal control method based on fuzzy logic (FL), fuzzy-neuro (FN) and multi-objective genetic algorithms (MOGA) for an isolated four-approach intersection with through and left-turning movemen... In this paper, a traffic signal control method based on fuzzy logic (FL), fuzzy-neuro (FN) and multi-objective genetic algorithms (MOGA) for an isolated four-approach intersection with through and left-turning movements is presented. This method has an adaptive signal timing ability, and can make adjustments to signal timing in response to observed changes.The 'urgency degree' term, which can describe the different user's demand for green time is used in decision-making by which strategy of signal timing can be determined. Using a fuzzy logic controller, we can determine whether to extend or terminate the current signal phase and select the sequences of phases. In this paper, a method based on fuzzy-neuro can be used to predict traffic parameters used in fuzzy logic controller. The feasibility of using a multi-objective genetic algorithm ( MOGA) to find a group of optimizing sets of parameters for fuzzy logic controller depending on different objects is also demonstrated. Simulation results show that the proposed methed is effecfive to adjust the signal timing in response to changing traffic conditions on a real-time basis, and the controller can produce lower vehicle delays and percentage of stopped vehicles than a traffic-actuated controller. 展开更多
关键词 traffic signal control Fuzzy logic Fuzzy-neuro Multi-objective genetic algorithms.
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Identification of Information-Seeking Behaviors from Air Traffic Controllers′ Eye Movements
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作者 Wang Yanjun Liu Yinxin +2 位作者 Cong Wei Xu Xinhua Hu Minghua 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第4期433-441,共9页
Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired fro... Air traffic controllers are the important parts of air traffic management system who are responsible for the safety and efficiency of the system.They make traffic management decisions based on information acquired from various sources.The understanding of their information seeking behaviors is still limited.We aim to identify controllers′ behavior through the examination of the correlations between controllers′eye movements and air traffic.Sixteen air traffic controllers were invited to participate real-time simulation experiments,during which the data of their eye ball movements and air traffic were recorded.Tweny-three air traffic complexity metrics and six eye movements metrics were calculated to examine their relationships.Two correlational methods,Pearson′s correlation and Spearman′s correlation,were tested between every eye-traffic pair of metrics.The results indicate that controllers′two kinds of information-seeking behaviors can be identified from their eye movements:Targets tracking,and confliction recognition.The study on controllers′ eye movements may contribute to the understanding of information-seeking mechanisms leading to the development of more intelligent automations in the future. 展开更多
关键词 air traffic management eye movements Pearson correlations air traffic controller
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Optimizing Traffic Signals in Smart Cities Based on Genetic Algorithm
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作者 Nagham A.Al-Madi Adnan A.Hnaif 《Computer Systems Science & Engineering》 SCIE EI 2022年第1期65-74,共10页
Current traffic signals in Jordan suffer from severe congestion due to many factors,such as the considerable increase in the number of vehicles and the use of fixed timers,which still control existing traffic signals.... Current traffic signals in Jordan suffer from severe congestion due to many factors,such as the considerable increase in the number of vehicles and the use of fixed timers,which still control existing traffic signals.This condition affects travel demand on the streets of Jordan.This study aims to improve an intelligent road traffic management system(IRTMS)derived from the human community-based genetic algorithm(HCBGA)to mitigate traffic signal congestion in Amman,Jordan’s capital city.The parameters considered for IRTMS are total time and waiting time,and fixed timers are still used for control.By contrast,the enhanced system,called enhanced-IRTMS(E-IRTMS),considers additional important parameters,namely,the speed performance index(SPI),speed reduction index(SRI),road congestion index(R i),and congestion period,to enhance IRTMS decision.A significant reduction in congestion period was measured using E-IRTMS,improving by 13% compared with that measured using IRTMS.Meanwhile,the IRTMS result surpasses that of the current traffic signal system by approximately 83%.This finding demonstrates that the E-IRTMS based on HCBGA and with unfixed timers achieves shorter congestion period in terms of SPI,SRI,and R_(i) compared with IRTMS. 展开更多
关键词 Genetic algorithm traffic signal congestion smart cities
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Impacts of Coordinated Traffic Signal Control Strategies and Bus Priority
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《Journal of Civil Engineering and Architecture》 2012年第1期81-92,共12页
Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus prio... Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus priority in Swedish urban traffic signal systems are normally coordinated with fixed time plan selection. Within this framework local traffic actuated signal timing adjustments are applied based on detector inputs aimed to reduce the number of vehicles in the dilemma zone. Active bus priority is also achieved with the aim to display green signal at the arrival of the bus to the stop line. Due to lack of knowledge of traffic performance impacts of these techniques a major research study was undertaken funded by the Swedish Road Administration. The aim was to evaluate the following control strategies using Stockholm as case study: (1) Fixed time coordination (FTC); (2) Fixed time coordination with local signal timing adjustment (FTC-LTA); (3) FTC-LTA with active bus priority (PRIBUSS); (4) Self-optimizing control (SPOT) with active bus priority. The methodologies for the study included field data collection using mobile and stationary techniques, offiine signal timing calculations with TRANSYT, microscopic simulation modeling using the HUTSIM model. The study obtained the following results: (1) Local traffic adjustment with the manual FTC reduced total delay by 1%. (2) Signal timings determined using TRANSYT reduced the average intersection delay by 9% compared to manual signal settings. (3) Local traffic adjustment reduced total delay by a further 5%. (4) Bus travel time was reduced by 11% using PRIBUSS, and 28% using SPOT. (5) Travel time for all vehicles did not increase using PRIBUSS, and was reduced by 6.5% with SPOT. Results of comparing PRIBUSS and SPOT to FTC-LTA were shown to be statistically significant. 展开更多
关键词 Bus priority traffic signals PRIBUSS SPOT FTC-LTA.
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Integrated Performance Measures for Bus Rapid Transit System and Traffic Signal Systems Using Trajectory Data
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作者 Jijo Kulathintekizhakethil Mathew Howell Li +2 位作者 Enrique Saldivar-Carrranza Matthew Duffy Darcy Michael Bullock 《Journal of Transportation Technologies》 2022年第4期833-860,共28页
Bus rapid transit (BRT) systems have been implemented in many cities over the past two decades. Widespread adoption of General Transit Feed Specification (GTFS), the deployment of high-fidelity bus GPS data tracking, ... Bus rapid transit (BRT) systems have been implemented in many cities over the past two decades. Widespread adoption of General Transit Feed Specification (GTFS), the deployment of high-fidelity bus GPS data tracking, and anonymized high-fidelity connected vehicle data from private vehicles have provided new opportunities for performance measures that can be used by both transit agencies and traffic signal system operators. This paper describes the use of trajectory-based data to develop performance measures for a BRT system in Indianapolis, Indiana. Over 3 million data records during the 3-month period between March and May 2022 are analyzed to develop visualizations and performance metrics. A methodology to estimate the average delay and schedule adherence is presented along a route comprised of 74 signals and 28 bus stations. Additionally, this research demonstrates how these performance measures can be used to evaluate dedicated and non-dedicated bus lanes with general traffic. Travel times and reliability of buses are compared with nearly 30 million private vehicle trips. Results show that median travel time for buses on dedicated bi-directional lanes is within one minute of general traffic and during peak periods the buses are often faster. Schedule adherence was observed to be more challenging, with approximately 3% of buses arriving within 1 minute on average during the 5AM hour and 5% of buses arriving 6 - 9 minutes late during the 5PM hour. The framework and performance measures presented in this research provide agencies and transportation professionals with tools to identify opportunities for adjustments and to justify investment decisions. 展开更多
关键词 Connected Vehicle Trajectory Bus Rapid Transit Performance traffic signal Retiming Schedules
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Intelligent Virtual Assistant System(IVAS) for Air Traffic Controllers
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作者 Anusha DILHANI Ruminda J WIMALASIRI 《Instrumentation》 2021年第1期43-50,共8页
Air traffic control is an essential obligation in the aviation industry to have safe and efficient air transportation.Year by year,the workload and on-job-stress of the air traffic controllers are rapidly increasing d... Air traffic control is an essential obligation in the aviation industry to have safe and efficient air transportation.Year by year,the workload and on-job-stress of the air traffic controllers are rapidly increasing due to the rapid growth of air traveling.Controllers are usually dealing with multiple aircrafts at a time and must make quick and accurate decisions to ensure the safety of aircrafts.Heavy workload and high responsibilities create air traffic control a stressful job that sometimes could be error-prone and time-consuming,since controlling and decision-making are solely dependent on human intelligence.To provide effective solutions for the mentioned on the job challenges of the controllers,this study proposed an intelligent virtual assistant system(IVAS)to assist the controllers thereby to reduce the controllers’workload.Consisting of four main parts,which are voice recognition,display conversation on screen,task execution,and text to speech,the proposed system is developed with the aid of artificial intelligence(AI)techniques to make speedy decisions and be free of human interventions.IVAS is a computer-based system that can be activated by the voice of the air traffic controller and then appropriately assist to control the flight.IVAS identifies the words spoken by the controller and then a virtual assistant navigates to collect the data requested from the controllers,which allows additional or free time to the controllers to contemplate more on the work or could assist to another aircraft.The Google speech application programming interface(API)converts audio to text to recognize keywords.AI agent is trained using the Hidden marko model(HMM)algorithm such that it could learn the characteristics of the distinct voices of the controllers.At this stage,the proposed IVAS can be used to provide training for novice air traffic controllers effectively.The system is to be developed as a real-time system which could be used at the air traffic controlling base for actual traffic controlling purposes and the system is to be further upgraded to perform the task by recognizing keywords directly from the pilot voice command. 展开更多
关键词 Artificial Intelligence Air traffic controller Intelligent Virtual Assistant
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