scholarly journals Sustainable Design of Diverging Diamond Interchange: Development of Warrants for Improving Operational Performance

2020 ◽  
Vol 12 (14) ◽  
pp. 5840
Author(s):  
Meshal Almoshaogeh ◽  
Hatem Abou-Senna ◽  
Essam Radwan ◽  
Husnain Haider
Keyword(s):  
Performance Comparison ◽  
Simulation Software ◽  
Average Delay ◽  
Innovative Design ◽  
Left Turn ◽  
Conventional Design ◽  
Safety Risks ◽  
Traffic Volumes ◽  
Diamond Interchanges ◽  
Measures Of Effectiveness

Conventional diamond interchanges are facing ever-growing challenges related to traffic operations and safety risks due to increasing traffic volumes and worsening congestions. The agencies are well aware of the high socioeconomic (e.g., user delay cost, fuel cost, and high accident rates) and environmental losses (traffic emissions due to vehicles queuing) associated with the conventional interchange design. This paper provides insight into the different factors that affect the sustainability performance (operational and safety) of a conventional interchange through its redesign into the Diverging Diamond Interchange (DDI) with the increased left-turn demand. It also assesses the need to redesign an interchange to improve the efficiency. Two interchanges that have DDI designs were selected for investigations, and the required data were collected from the relevant agency. The average delay and the capacity were used as the Measures of Effectiveness (MOEs) for data analysis. Numerous factors, that affected these MOEs, were used to design an experiment. This experiment included different levels of volumes, geometric designs, and signal plans. The micro-simulation software (VISSIM 8.0) was employed to calibrate and validate the existing conditions through several steps, including signal optimization and driving behavior parameter optimization. The analysis of the results detected the key thresholds of switching from the conventional design to the innovative design under 90 different scenarios. Finally, the sustainability evaluation of DDI and Conventional Design Interchange was conducted based on their operation and safety performance comparison. The results and findings of this research will act as a guideline for decision-makers regarding when they should consider switching from the conventional interchange design to an innovative design.

scholarly journals A General Maximum Progression Model to Concurrently Synchronize Left-Turn and through Traffic Flows on an Arterial

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Binbin Jing ◽  
Jianmin Xu
Keyword(s):  
Travel Time ◽  
Traffic Control ◽  
General Model ◽  
Delay Time ◽  
Simulation Software ◽  
Traffic Flows ◽  
Average Delay ◽  
Left Turn ◽  
Progression Model ◽  
Time Space

In the existing bandwidth-based methods, through traffic flows are considered as the coordination objects and offered progression bands accordingly. However, at certain times or nodes in the road network, when the left-turn traffic flows have a higher priority than the through traffic flows, it would be inappropriate to still provide the progression bands to the through traffic flows; the left-turn traffic flows should instead be considered as the coordination objects to potentially achieve better control. Considering this, a general maximum progression model to concurrently synchronize left-turn and through traffic flows is established by using a time-space diagram. The general model can deal with all the patterns of the left-turn phases by introducing two new binary variables into the constraints; that is, these variables allow all the patterns of the left-turn phases to deal with a single formulation. By using the measures of effectiveness (average delay time, average vehicle stops, and average travel time) acquired by a traffic simulation software, VISSIM, the validity of the general model is verified. The results show that, compared with the MULTIBAND, the proposed general model can effectively reduce the delay time, vehicle stops, and travel time and, thus, achieve better traffic control.

Simulation Study of Truck Traffic at Single-Lane Roundabouts with and without Slip Lanes

2015 ◽  
Vol 2517 (1) ◽  
pp. 80-86
Author(s):  
Majed Al-Ghandour
Keyword(s):  
Confidence Interval ◽  
Simulation Study ◽  
Free Flow ◽  
Nonlinear Relationship ◽  
Truck Traffic ◽  
Average Delay ◽  
Left Turn ◽  
Delay Performance ◽  
Traffic Volumes ◽  
Total Average

As transportation planners and engineers design useful and effective roundabouts, these professionals are challenged by the need to accommodate safely truck traffic and high truck volumes in particular. Delay is a major challenge with truck traffic, especially with returning left-turning trucks. The delay performance of single-lane roundabouts with an adjacent slip lane for right turns was considered under various truck traffic percentages and two slip lane exit types (free flow and yield). A microsimulation assessment compared four percentages of right-turn truck traffic: 0% (no trucks), 5%, 45%, and 80%. Results indicate that the average delay of a roundabout with a slip lane under various truck traffic percentages is a nonlinear relationship with slip lane volumes and is sensitive to changes in truck traffic percentages before oversaturation is reached. As expected, results indicate that a free-flow slip lane exit type significantly reduces total average delay in roundabouts compared with having no slip lane with truck traffic. Yield slip lane exit types also reduced total average delay from truck traffic in roundabouts, but to a lesser degree than free-flow slip lane exit types. At higher truck traffic volumes, overall average roundabout delay decreased 15% (estimated VISSIM 95% confidence interval of reduction estimated between —16% and —2%) with a free-flow slip lane exit type. Finally, returning left-turn trucks increased total roundabout average delay significantly, by 64%.

Operating Performance of Diverging Diamond Interchanges

2019 ◽  
Vol 2673 (11) ◽  
pp. 801-812 ◽  
Author(s):  
Michael Hunter ◽  
Angshuman Guin ◽  
James Anderson ◽  
Sung Jun Park
Keyword(s):  
Sensitivity Analysis ◽  
Superior Performance ◽  
Operational Performance ◽  
Second Step ◽  
Traffic Patterns ◽  
Jimmy Carter ◽  
Microscopic Simulation ◽  
Left Turn ◽  
Traffic Volumes ◽  
Diamond Interchanges

As the result of changing traffic patterns, many conventional intersections and interchanges can no longer accommodate growing traffic volumes and heavy turning movements. In response, there are various innovative intersection and interchange designs proposed and implemented to better accommodate these changes, and the diverging diamond interchange (DDI) is one of these alternatives. While there is a significant amount of research on the relative performance of DDIs and conventional diamond interchanges (CDIs), a clear set of guidance on demand conditions under which a DDI is likely an operationally more efficient solution is not readily available. This effort conducts a sensitivity analysis of CDI and DDI operational performance under various interchange lane configurations, including the selected study area of the Jimmy Carter Boulevard and I-85 interchange in Norcross, Georgia, under varying traffic demands and turn-movement ratios. The sensitivity analysis explores the detailed conditions in which one interchange configuration provides superior performance over the other. The sensitivity analysis is structured into a two-step process with a critical lane volume (CLV) analysis as the first step, followed by a VISSIM microscopic simulation study as the second step. Overall, the study found that a CDI is likely to be the preferred option at locations with traffic volumes well below capacity and cross-street left-turn traffic proportions below 30% of the total cross-street demand, and a DDI is likely to be preferred at locations with traffic volumes near capacity and cross-street left-turn proportions exceeding 50% of the total cross-street demand.

Neurofuzzy Control to Actuated-Coordinated System at Closely-Spaced Intersections

2013 ◽  
Vol 321-324 ◽  
pp. 1249-1258 ◽  
Author(s):  
Xiao Li Sun ◽  
Tom Urbanik ◽  
Lee D. Han
Keyword(s):  
Control System ◽  
Fuzzy Controller ◽  
Signal Control ◽  
Average Delay ◽  
Left Turn ◽  
Traffic Demand ◽  
Real Time Traffic ◽  
Neurofuzzy Control ◽  
Wide Range ◽  
Traffic Volumes

This paper presents a neurofuzzy signal control system to improve the efficiency at closely-spaced signalized intersections. Building on the conventional actuated-coordinated control system, the neurofuzzy controller establishes a “secondary coordination” between the upstream coordinated phase and the downstream non-coordinated phase based on real-time traffic demand. Under the neurofuzzy signal control, the traffic from the upstream intersection can arrive and join the queue at the downstream left turn lane and be served, and therefore reduce the possibility of being delayed at the downstream intersection. The membership functions in the fuzzy controller are calibrated to further the performance. The simulation results indicate that the neurofuzzy signal control consistently outperformed to the conventional actuated-coordinated controller, in terms of reduction in system-wide average delay and average number of stops per vehicle, under a wide range of traffic volumes, especially under higher demand conditions.

scholarly journals An Optimization Model of Multi-Intersection Signal Control for Trunk Road under Collaborative Information

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xun Li ◽  
Zhengfan Zhao ◽  
Li Liu ◽  
Yao Liu ◽  
Pengfei Li
Keyword(s):  
Optimization Model ◽  
Delay Time ◽  
Traffic Simulation ◽  
Simulation Software ◽  
Transmission Model ◽  
Signal Control ◽  
Cell Transmission Model ◽  
Average Delay ◽  
Main Trunk ◽  
Average Delay Time

We proposed a signal control optimization model for urban main trunk line intersections. Four-phase intersection was analyzed and modeled based on the Cell Transmission Model (CTM). CTM and signal control model in our study had both been improved for multi-intersections by three-phase theory and information-exchanging. To achieve a real-time application, an improved genetic algorithm (GA) was proposed finally, the DISCO traffic simulation software was used for numerical simulation experiment, and comparisons with the standard GA and CTM were reported in this paper. Experimental results indicate that our searching time is less than that of SGA by 38%, and our method needs only 1/3 iteration time of SGA. According to our DISCO traffic simulation processing, compared with SGA, if the input traffic flow is changed from free phase to synchronized phase, for example, less than 900 vel/h, the delay time can reduce to 87.99% by our method, and the minimum delay time is 77.76% of existing method. Furthermore, if input traffic volume is increased to 1200 vel/h or more at the synchronized phase, the summary and minimum values of average delay time are reduced to 81.16% and 75.83%, respectively, and the average delay time is reduced to 17.72 seconds.

scholarly journals Innovative design and simulation of clothing products for children with atypical changes in conformation and posture

2017 ◽  
Vol 68 (01) ◽  
pp. 63-68
Author(s):  
POPESCU GEORGETA ◽  
NICULESCU CLAUDIA ◽  
OLARU SABINA
Keyword(s):  
Age Groups ◽  
Simulation Software ◽  
The Body ◽  
Virtual Simulation ◽  
Simulation And Modeling ◽  
Anthropometric Data ◽  
Innovative Design ◽  
3D Simulations ◽  
The One ◽  
Product Verification

The paper presents the design stages of clothing products for children with atypical changes in conformation and posture and the virtual simulation and modeling for the body-product verification. The design technology is an innovative one that allows obtaining the customized patterns by made-to-measure method applied to standardized patterns for all age groups of children, selecting the one corresponding to the typo-dimension of studied subject. The large number of existing anthropometric data and viewing virtual body allows the identification of areas of the body that shows changes in conformation and posture and provides information to the designer and pattern technician in order to develop suitable products in terms of functionality and aesthetics. With the help of simulation software Optitex 3D simulations modeling is performed on the body until fulfillment of the compliance degree for the designed product.

scholarly journals PERFORMANCE COMPARISON WITH ACCESSIBILITY PREDICTION AND LINK BREAKAGE PREDICTION IN MANETS

2015 ◽  
pp. 48-54
Author(s):  
TEJAL ARVIND SONAWALE ◽  
SHIKHA NEMA
Keyword(s):  
Ad Hoc ◽  
Power Level ◽  
Performance Comparison ◽  
Delivery Ratio ◽  
Route Discovery ◽  
Network Resources ◽  
Average Delay ◽  
Network Bandwidth ◽  
Multiple Routes ◽  
Hoc Networks

Ad Hoc Networks face a lot of problems due to issues like mobility, power level, load of the network, bandwidth constraints, dynamic topology which lead to link breaks, node break down and increase in overhead. As nodes are changing their position consistently, routes are rapidly being disturbed, thereby generating route errors and new route discoveries. The need for mobility awareness is widely proclaimed. In our dissertation we present a scheme AOMDV-APLP that makes AOMDV aware of accessibility of neighbor nodes in the network. Nodes acquire the accessibility information of other nodes through routine routing operations and keep in their routing table. Based on this information route discovery is restricted to only “accessible” and “start” nodes. Further route with the strongest signal strength is selected from multiple routes using Link life value predicted by Link Breakage prediction technique. Simulation result shows that using accessibility and link life knowledge in route discovery process MAC overhead, routing overhead and average delay is reduced 3 times, and improve the Packet delivery ratio to a large extent than standard AOMDV which reflects effective use of network resources.

scholarly journals An innovative design for left turn bicycles at continuous flow intersections

2019 ◽  
Vol 7 (1) ◽  
pp. 1305-1322 ◽  
Author(s):  
Jing Zhao ◽  
Xing Gao ◽  
Victor L. Knoop
Keyword(s):  
Continuous Flow ◽  
Innovative Design ◽  
Left Turn

Developing Decision Boundaries for Left-Turn Treatments

2020 ◽  
Vol 2674 (5) ◽  
pp. 315-326
Author(s):  
Michael Adamson ◽  
Grant G. Schultz ◽  
Mitsuru Saito ◽  
Michael D. Stevens
Keyword(s):  
Linear Regression Analysis ◽  
Simulation Models ◽  
Assessment Model ◽  
Final Decision ◽  
Contour Map ◽  
Left Turn ◽  
Contour Maps ◽  
Traffic Volumes ◽  
Decision Boundaries ◽  
Statistical Analysis Software

The purpose of this research was to evaluate the interaction of left-turn and opposing through traffic volumes for permitted and protected left-turn phasing at intersections and develop boundaries that help identify when to switch from permitted to protected phasing at signalized intersections. Permitted phasing allows vehicles to turn left after yielding to opposing vehicles; protected phasing provides an exclusive phase for vehicles to turn left without opposition; and protected-permitted phasing combines these phasing alternatives, allowing both permitted and protected turning movements. Intersections with 1, 2, and 3 opposing-lane configurations with permitted and protected-permitted models (split into green times of 10, 15, and 20 s) were analyzed for a total of 12 simulation models. Each model was divided into 100–225 different volume scenarios, with incremental increases in left-turn and opposing volumes. By exporting trajectory files from VISSIM and importing these into the Surrogate Safety Assessment Model, crossing conflicts for each volume combination in each model were extracted. MATLAB was then used to create contour maps representing the number of crossing conflicts per hour associated with different combinations of left-turn and opposing volume. Basic decision boundaries were examined in each contour map. Statistical analysis software was used to perform a linear regression analysis on transformed data and to develop natural log-based equations that form the decision boundaries for each configuration and phase alternative. These equations were graphed and final decision boundaries developed for the 1-, 2-, and 3-lane configurations between permitted and protected-permitted phasing as well as between protected-permitted and protected phasing.

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