This page has only limited features, please log in for full access.
As an unconventional design to alleviate the conflict between left-turn and through vehicles, Continuous Flow Intersection (CFI) has obvious advantages in improving the sustainability of roadway. So far, the design manuals and guidelines for CFI are not enough sufficient, especially for the displaced left-turn lane length of CFI. And the results of existing research studies are not operational, making it difficult to put CFI into application. To address this issue, this paper presents a methodological procedure for determination and evaluation of displaced left-turn lane length based on the entropy method considering multiple performance measures for sustainable transportation, including traffic efficiency index, environment effect index and fuel consumption. VISSIM and the surrogate safety assessment model (SSAM) were used to simulate the operational and safety performance of CFI. The multi-attribute decision-making method (MADM) based on an entropy method was adopted to determine the suitability of the CFI schemes under different traffic demand patterns. Finally, the procedure was applied to a typical congested intersection of the arterial road with heavy traffic volume and high left-turn ratio in Xi’an, China, the results showed the methodological procedure is reasonable and practical. According to the results, for the studied intersection, when the Volume-to-Capacity ratio (V/C) in the westbound and eastbound lanes is less than 0.5, the length of the displaced left-turn lanes can be selected in the range of 80 to 170 m. Otherwise, other solutions should be considered to improve the traffic efficiency. The simulation results of the case showed CFI can significantly improve the traffic efficiency. In the best case, compared with the conventional intersection, the number of vehicles increases by 13%, delay, travel time, number of stops, CO emission, and fuel consumption decrease by 41%, 29%, 25%, 17%, and 17%, respectively.
BingHong Pan; Shasha Luo; Jinfeng Ying; Yang Shao; Shangru Liu; Xiang Li; Jiaqi Lei. Evaluation and Analysis of CFI Schemes with Different Length of Displaced Left-Turn Lanes with Entropy Method. Sustainability 2021, 13, 6917 .
AMA StyleBingHong Pan, Shasha Luo, Jinfeng Ying, Yang Shao, Shangru Liu, Xiang Li, Jiaqi Lei. Evaluation and Analysis of CFI Schemes with Different Length of Displaced Left-Turn Lanes with Entropy Method. Sustainability. 2021; 13 (12):6917.
Chicago/Turabian StyleBingHong Pan; Shasha Luo; Jinfeng Ying; Yang Shao; Shangru Liu; Xiang Li; Jiaqi Lei. 2021. "Evaluation and Analysis of CFI Schemes with Different Length of Displaced Left-Turn Lanes with Entropy Method." Sustainability 13, no. 12: 6917.
The decision sight distance (DSD) at freeway exits is a major factor affecting traffic safety. Based on the Hechizhai Interchange in Xi’an City (Shaanxi Province, China), this paper designs a simulation experiment. Through a simulator study and a questionnaire survey, this paper discusses the impact of the DSD, 1.25 times the stopping sight distance (SSD) and a circular curve deflection on a driver’s driving state (including steering wheel angle rate and steering wheel angle frequency domain). Thirty volunteers participated in this research. The result shows that (1) it is safer to drive on an exit that meets DSD. (2) If it only meets the 1.25 times the SSD requirement, the overloaded driving tasks and operation would be more likely to cause crashes. The driving state of the driver on the right circular curve is obviously better than that on the left circular curve, because changing lanes to the right on the left circular curve does not meet the driver’s expectations. (3) Left and right circular curve should be treated differently in the driving area and the constant sight distance requirements should not be applied. (4) The left circular curve should be more stringent to ensure driving safety.
Xizhen Zhou; BingHong Pan; Yang Shao. Evaluating the Impact of Sight Distance and Geometric Alignment on Driver Performance in Freeway Exits Diverging Area Based on Simulated Driving Data. Sustainability 2021, 13, 6368 .
AMA StyleXizhen Zhou, BingHong Pan, Yang Shao. Evaluating the Impact of Sight Distance and Geometric Alignment on Driver Performance in Freeway Exits Diverging Area Based on Simulated Driving Data. Sustainability. 2021; 13 (11):6368.
Chicago/Turabian StyleXizhen Zhou; BingHong Pan; Yang Shao. 2021. "Evaluating the Impact of Sight Distance and Geometric Alignment on Driver Performance in Freeway Exits Diverging Area Based on Simulated Driving Data." Sustainability 13, no. 11: 6368.
Conventional four-legged intersections are inefficient under heavy traffic requirements and are prone to congestion problems. Unconventional intersections with innovative designs allow for more efficient traffic operations and can increase the capacity of the intersection, in some cases. Common unconventional designs for four-legged intersections include the upstream signalized crossover intersection (USC), continuous flow intersection (CFI), and parallel flow intersection (PFI). At present, an increasing number of cities are using such unconventional designs to improve the performance of their intersections. In the reconstruction of original intersections or the design of new intersections, the question of how to more reasonably select the form of unconventional intersection becomes particularly critical. Therefore, we selected a typical intersection in Xi’an for optimization and investigated traffic data for this intersection. The traffic operations, with respect to the four solutions of a conventional intersection, USC, CFI, and PFI, were evaluated using the VISSIM software. Then, we evaluated the suitability of each solution under different situations using the CRITIC (CRiteria Importance Through Intercriteria Correlation) method, which is a multi-criteria decision-making (MCDM) method that enables a more comprehensive and integrated evaluation of the four solutions by taking into account the comparative intensities and conflicting character among the indices. The results show that the conventional intersection is only applicable to the case of very low traffic volume; PFI has the advantage in the case of moderate and high traffic volume; CFI performs better in the case of high traffic volume; and USC is generally inferior to CFI and PFI, although it has greater improvement, compared with the conventional solution, in a few cases.
BingHong Pan; Shangru Liu; Zhenjiang Xie; Yang Shao; Xiang Li; Ruicheng Ge. Evaluating Operational Features of Three Unconventional Intersections under Heavy Traffic Based on CRITIC Method. Sustainability 2021, 13, 4098 .
AMA StyleBingHong Pan, Shangru Liu, Zhenjiang Xie, Yang Shao, Xiang Li, Ruicheng Ge. Evaluating Operational Features of Three Unconventional Intersections under Heavy Traffic Based on CRITIC Method. Sustainability. 2021; 13 (8):4098.
Chicago/Turabian StyleBingHong Pan; Shangru Liu; Zhenjiang Xie; Yang Shao; Xiang Li; Ruicheng Ge. 2021. "Evaluating Operational Features of Three Unconventional Intersections under Heavy Traffic Based on CRITIC Method." Sustainability 13, no. 8: 4098.
The interchange diverging area is a bottleneck section of the freeway. If the capacity of a two-lane exit cannot meet the traffic demand, it will lead to a reduction in the overall operational efficiency of the freeway. To fundamentally improve the capacity of the diverging area, designers have considered expanding the two-lane exit to a three-lane exit. However, the existing Chinese design specifications do not include a design for a three-lane exit, and the method of increasing the number of ramp lanes by setting up auxiliary lanes according to traditional design concepts leads to the mainline widening section being too long, thus increasing the construction land use and project cost. Therefore, this paper proposes an innovative three-lane exit design based on a specific two-lane exit at an interchange in Xi’an. According to the different traffic organization methods, three microscopic simulation models of diverging areas were constructed by using VISSIM. The entropy method was used to objectively calculate the weights of the four selected evaluation indexes, and a comprehensive evaluation and applicability analysis of the current situation and the three-lane exit design schemes were conducted. The results show that the optimal combination of the schemes calculated by the entropy method increases the traffic volume by up to 40% and reduces delays by 50-88%.
BingHong Pan; Zhenjiang Xie; Shangru Liu; Yang Shao; Junjie Cai. Evaluating Designs of a Three-Lane Exit Ramp Based on the Entropy Method. IEEE Access 2021, 9, 53436 -53451.
AMA StyleBingHong Pan, Zhenjiang Xie, Shangru Liu, Yang Shao, Junjie Cai. Evaluating Designs of a Three-Lane Exit Ramp Based on the Entropy Method. IEEE Access. 2021; 9 (99):53436-53451.
Chicago/Turabian StyleBingHong Pan; Zhenjiang Xie; Shangru Liu; Yang Shao; Junjie Cai. 2021. "Evaluating Designs of a Three-Lane Exit Ramp Based on the Entropy Method." IEEE Access 9, no. 99: 53436-53451.
This article proposes a new approach for computing a semiexplicit form of the solution to a class of traffic flow problems encoded by a Hamilton-Jacobi (HJ) partial differential equation (PDE), with time-switched Hamiltonian. Using a characterization of the problem derived from viability theory, we show that the solution associated with the problem can be formulated as a minimization problem involving the trajectory of an auxiliary dynamical system. A generalized Lax-Hopf formula for the switched Hamiltonian problem is derived, which enables us to compute the solution associated with affine initial or boundary conditions as a linear program involving the control function of the auxiliary dynamical system. This formulation allows us to compute the solution to the original problem exactly, unlike dynamic programming methods. In addition, this method allows one to very efficiently recompute the boundary conditions associated with an initial condition problem, allowing large-scale variable speed limit traffic control problems to be solved.
Yang Shao; Michael W. Levin; Stephen D. Boyles; Christian G. Claudel. Semianalytical Solutions to the Lighthill-Whitham-Richards Equation With Time-Switched Triangular Diagrams: Application to Variable Speed Limit Traffic Control. IEEE Transactions on Automation Science and Engineering 2020, PP, 1 -13.
AMA StyleYang Shao, Michael W. Levin, Stephen D. Boyles, Christian G. Claudel. Semianalytical Solutions to the Lighthill-Whitham-Richards Equation With Time-Switched Triangular Diagrams: Application to Variable Speed Limit Traffic Control. IEEE Transactions on Automation Science and Engineering. 2020; PP (99):1-13.
Chicago/Turabian StyleYang Shao; Michael W. Levin; Stephen D. Boyles; Christian G. Claudel. 2020. "Semianalytical Solutions to the Lighthill-Whitham-Richards Equation With Time-Switched Triangular Diagrams: Application to Variable Speed Limit Traffic Control." IEEE Transactions on Automation Science and Engineering PP, no. 99: 1-13.
The impact of work zones on traffic is a common problem encountered in traffic management. The reconstruction of roads is inevitable, and it is necessary and urgent to reduce the impact of the work zone on the operation of traffic. There are many existing research results on the influence of highway work zones, including management strategies, traffic flow control strategies, and various corresponding model theories. There are also many research results on the impacts of urban road and subway construction on traffic operation, including construction efficiency, economic impact, and travel matrix. However, there are few studies concerning the choice of work zone location, and most previous studies have assumed that the work zone choice was scientific and reasonable. Therefore, it is reasonable to choose the location of the work zone and to assess whether there is room for improvement in the road form of the work zone, but this remains a research gap. Therefore, we studied a seven-lane main road T-intersection in Xi’an, China, and investigated a work zone located at this intersection that caused a road offset, leading to the non-aligned flow of main traffic. We designed two road improvement schemes and multiple transition schemes, used VISSIM software to evaluate the traffic operation of the two schemes, and used the entropy method to choose the suitability of the two schemes under different conditions. According to the results, in the best case, the driving time, delay, and number of stops are reduced by 44%, 66%, and 92%.
Yang Shao; Zhongbin Luo; Huan Wu; Xueyan Han; BingHong Pan; Shangru Liu; Christian Claudel. Evaluation of Two Improved Schemes at Non-Aligned Intersections Affected by a Work Zone with an Entropy Method. Sustainability 2020, 12, 5494 .
AMA StyleYang Shao, Zhongbin Luo, Huan Wu, Xueyan Han, BingHong Pan, Shangru Liu, Christian Claudel. Evaluation of Two Improved Schemes at Non-Aligned Intersections Affected by a Work Zone with an Entropy Method. Sustainability. 2020; 12 (14):5494.
Chicago/Turabian StyleYang Shao; Zhongbin Luo; Huan Wu; Xueyan Han; BingHong Pan; Shangru Liu; Christian Claudel. 2020. "Evaluation of Two Improved Schemes at Non-Aligned Intersections Affected by a Work Zone with an Entropy Method." Sustainability 12, no. 14: 5494.
Traditional U-turn designs can improve operational features obviously, while U-turn diversions and merge segments still cause traffic congestion, conflicts, and delays. An exclusive spur dike U-turn lane design (ESUL) is proposed here to solve the disadvantages of traditional U-turn designs. To evaluate the operation performance of ESUL, a traffic simulation protocol is needed. The whole simulation process includes five steps: data collection, data analysis, simulation model build, simulation calibration, and sensitive analysis. Data collection and simulation model build are two critical steps and are described later in greater detail. Three indexes (travel time, delay, and number of stops) are commonly used in the evaluation, and other parameters can be measured from the simulation according to experimental needs. The results show that the ESUL significantly diminishes the disadvantages of traditional U-turn designs. The simulation can be applied to solve microscopic traffic problems, such as in single or several adjacent intersections or short segments. This method is not suitable for larger scale road networks or evaluations without data collection.
Yang Shao; Hongtao Yu; Huan Wu; Xueyan Han; Xizhen Zhou; Christian G. Claudel; Hualing Zhang; Chen Yang. Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation. Journal of Visualized Experiments 2020, e60675 .
AMA StyleYang Shao, Hongtao Yu, Huan Wu, Xueyan Han, Xizhen Zhou, Christian G. Claudel, Hualing Zhang, Chen Yang. Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation. Journal of Visualized Experiments. 2020; (156):e60675.
Chicago/Turabian StyleYang Shao; Hongtao Yu; Huan Wu; Xueyan Han; Xizhen Zhou; Christian G. Claudel; Hualing Zhang; Chen Yang. 2020. "Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation." Journal of Visualized Experiments , no. 156: e60675.
Driving safety in tunnels has always been an issue of great concern. Establishing delineators to improve drivers’ instantaneous cognition of the surrounding environment in tunnels can effectively enhance driver safety. Through a simulation study, this paper explored how delineators affect drivers’ gaze behavior (including fixation and scanpath) in tunnels. In addition to analyzing typical parameters, such as fixation position and fixation duration in areas of interest (AOIs), by modeling drivers’ switching process as Markov chains and calculating Shannon’s entropy of the fit Markov model, this paper quantified the complexity of individual switching patterns between AOIs under different delineator configurations and with different road alignments. A total of 25 subjects participated in this research. The results show that setting delineators in tunnels can attract drivers’ attention and make them focus on the pavement. When driving in tunnels equipped with delineators, especially tunnels with both wall delineators and pavement delineators, the participants exhibited a smaller transition entropy H t and stationary entropy H s , which can greatly reduce drivers’ visual fatigue. Compared with left curve and right curve, participants obtained higher H t and H s values in the straight section.
Xueyan Han; Yang Shao; ShaoWei Yang; Peng Yu. Entropy-Based Effect Evaluation of Delineators in Tunnels on Drivers’ Gaze Behavior. Entropy 2020, 22, 113 .
AMA StyleXueyan Han, Yang Shao, ShaoWei Yang, Peng Yu. Entropy-Based Effect Evaluation of Delineators in Tunnels on Drivers’ Gaze Behavior. Entropy. 2020; 22 (1):113.
Chicago/Turabian StyleXueyan Han; Yang Shao; ShaoWei Yang; Peng Yu. 2020. "Entropy-Based Effect Evaluation of Delineators in Tunnels on Drivers’ Gaze Behavior." Entropy 22, no. 1: 113.
Poor visual conditions in tunnels can easily cause traffic accidents, and it is difficult for emergency services to reach these areas. As an economical and effective visual guiding device, delineators have attracted wide attention. Based on the actual alignment of the Qinling Mountain No.1, No.2 and No.3 tunnels of the G5 Expressway in Xi’an City (Shaanxi Province, China), this paper designs a simulation experiment. Through a simulator study and a questionnaire survey, this paper discusses how delineators affect drivers’ visual characteristics (including fixation area and pupil size) in different settings and with different road alignments. Twenty-five subjects participated in this research. The results show that setting delineators in tunnels can continuously guide drivers’ vision and attract their attention to focus on the pavement. Compared with setting only pavement delineators, setting wall delineators and pavement delineators together can provide better guiding effects and ensure driving safety in both straight and curved sections. In addition, when driving in tunnels equipped with delineators, especially tunnels with both wall delineators and pavement delineators, the participants exhibited a smaller pupil diameter and lower pupil diameter change rate. In terms of the relationship between pupil size and road alignment, the results indicated that regardless of what type of delineator was used, the drivers exhibited the smallest pupil size and lowest pupil change rate when driving on the straight section compared with the curved sections.
Xueyan Han; Yang Shao; BingHong Pan; Peng Yu; Bin Li. Evaluating the impact of setting delineators in tunnels based on drivers’ visual characteristics. PLOS ONE 2019, 14, e0225799 .
AMA StyleXueyan Han, Yang Shao, BingHong Pan, Peng Yu, Bin Li. Evaluating the impact of setting delineators in tunnels based on drivers’ visual characteristics. PLOS ONE. 2019; 14 (12):e0225799.
Chicago/Turabian StyleXueyan Han; Yang Shao; BingHong Pan; Peng Yu; Bin Li. 2019. "Evaluating the impact of setting delineators in tunnels based on drivers’ visual characteristics." PLOS ONE 14, no. 12: e0225799.
Direct left turns (DLTs) could cause traffic slowdown, delay, stops, and even accidents on intersections, especially on no-median roads. Channelization and signalization can significantly diminish negative impact of DLTs. In China, a total of 56 large and medium-sized cities, including 17 provincial capitals, have adopted vehicle restriction policies due to traffic congestion, vehicle energy conservation and emission reduction, which cause travel inconvenience for citizens. This paper mainly studies signalization and channelization selections at intersections based on an entropy method. Based on the commonly used three evaluation indexes, the number of vehicles, CO emissions and fuel consumption have been added. The entropy evaluation method (EEM) method is innovatively used to objectively calculate the weight of the six indexes, which carry out the optimal traffic volume combinations for intersections of present situation, channelization and signalization. A VISSIM simulation is also used to evaluate the operating status of three conditions. The results show that EEM could help enormously in choosing different methods at a certain intersection. With the EEM, six indexes decrease by 20–70% at most.
Yang Shao; Xueyan Han; Huan Wu; Christian G. Claudel. Evaluating Signalization and Channelization Selections at Intersections Based on an Entropy Method. Entropy 2019, 21, 808 .
AMA StyleYang Shao, Xueyan Han, Huan Wu, Christian G. Claudel. Evaluating Signalization and Channelization Selections at Intersections Based on an Entropy Method. Entropy. 2019; 21 (8):808.
Chicago/Turabian StyleYang Shao; Xueyan Han; Huan Wu; Christian G. Claudel. 2019. "Evaluating Signalization and Channelization Selections at Intersections Based on an Entropy Method." Entropy 21, no. 8: 808.
The traditional U-turn design has significantly improved traffic operations for relieving traffic congestion. However, the U-turn diversion and merge segments still cause traffic conflicts and delays. In this paper, an exclusive spur dike U-turn lane (ESUL) is proposed with the aim of addressing the disadvantages of the traditional U-turn design. ESUL provides a separate U-turn lane to diverge, decelerate, U-turn, accelerate and merge without interacting with through traffic. The effectiveness of ESUL is demonstrated through a field data investigation, simulation and analysis with VISSIM software. The proposed design is evaluated in terms of three parameters: travel time, delay and number of stops. Compared to the traditional U-turn design, ESUL can reduce travel time by 29.15%, delay by 66.70% and the number of stops by 100% at most. The results showed that ESUL has better performance than the traditional U-turn design and could be implemented to reduce traffic congestion and the potential hazards caused by U-turn maneuvers.
Yang Shao; Xueyan Han; Huan Wu; Huimin Shan; ShaoWei Yang; Christian G. Claudel. Evaluating the sustainable traffic flow operational features of an exclusive spur dike U-turn lane design. PLOS ONE 2019, 14, e0214759 .
AMA StyleYang Shao, Xueyan Han, Huan Wu, Huimin Shan, ShaoWei Yang, Christian G. Claudel. Evaluating the sustainable traffic flow operational features of an exclusive spur dike U-turn lane design. PLOS ONE. 2019; 14 (4):e0214759.
Chicago/Turabian StyleYang Shao; Xueyan Han; Huan Wu; Huimin Shan; ShaoWei Yang; Christian G. Claudel. 2019. "Evaluating the sustainable traffic flow operational features of an exclusive spur dike U-turn lane design." PLOS ONE 14, no. 4: e0214759.