Derivation of Decision Boundaries for Left-Turn Treatments at Signalized Intersections

2017 ◽  
Vol 2620 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Raessler ◽  
Jidong J. Yang
Keyword(s):  
Decision Making ◽  
Signalized Intersections ◽  
Maintenance Costs ◽  
Left Turn ◽  
Practical Guidelines ◽  
Decision Boundaries ◽  
Boundary Curves ◽  
Benefits And Costs

A new methodology is proposed to establish practical guidelines for four incremental left-turn treatments: ( a) permissive single left-turn lane, ( b) protected–permissive single left-turn lane, ( c) protected dual left-turn lanes with equal lane use, and ( d) protected dual left-turn lanes with unequal lane use. Decision boundaries were derived from the equilibrium at which the delays of two incremental treatments were equal. The benefits and costs associated with different left-turn treatments—including safety impact and construction and maintenance costs—also were considered. These benefits and costs effectually shift the boundary curves for more realistic decision making.

Modeling Capacity of Through Movement at Signalized Intersection Affected by Short Left-Turn Bay under Different Signal Settings

2021 ◽  
pp. 036119812110064
Author(s):  
Zihang Wei ◽  
Yunlong Zhang ◽  
Xiaoyu Guo ◽  
Xin Zhang
Keyword(s):  
Cycle Length ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Essential Factor ◽  
Highway Capacity ◽  
Left Turn ◽  
Highway Capacity Manual ◽  
Proposed Model ◽  
Vehicle Demand ◽  
The One

Through movement capacity is an essential factor used to reflect intersection performance, especially for signalized intersections, where a large proportion of vehicle demand is making through movements. Generally, left-turn spillback is considered a key contributor to affect through movement capacity, and blockage to the left-turn bay is known to decrease left-turn capacity. Previous studies have focused primarily on estimating the through movement capacity under a lagging protected only left-turn (lagging POLT) signal setting, as a left-turn spillback is more likely to happen under such a condition. However, previous studies contained assumptions (e.g., omit spillback), or were dedicated to one specific signal setting. Therefore, in this study, through movement capacity models based on probabilistic modeling of spillback and blockage scenarios are established under four different signal settings (i.e., leading protected only left-turn [leading POLT], lagging left-turn, protected plus permitted left-turn, and permitted plus protected left-turn). Through microscopic simulations, the proposed models are validated, and compared with existing capacity models and the one in the Highway Capacity Manual (HCM). The results of the comparisons demonstrate that the proposed models achieved significant advantages over all the other models and obtained high accuracies in all signal settings. Each proposed model for a given signal setting maintains consistent accuracy across various left-turn bay lengths. The proposed models of this study have the potential to serve as useful tools, for practicing transportation engineers, when determining the appropriate length of a left-turn bay with the consideration of spillback and blockage, and the adequate cycle length with a given bay length.

Operational Effects of the Consolidated Intersection Design on Urban and Suburban Arterials

2018 ◽  
Vol 2672 (17) ◽  
pp. 96-107
Author(s):  
Daniel J. Cook
Keyword(s):  
Travel Time ◽  
Signalized Intersections ◽  
Signal Timing ◽  
Left Turn ◽  
Vehicle Delay ◽  
Cycle Lengths ◽  
Expected Benefits ◽  
Traffic Signal Timing ◽  
Critical Phases ◽  
Pedestrian Crossing

Along urban and suburban arterials, closely-spaced signalized intersections are commonly used to provide access to adjacent commercial developments. Often, these signalized intersections are designed to provide full access to developments on both sides of the arterial and permit through, left-turn, and right-turn movements from every intersection approach. Traffic signal timing is optimized to reduce vehicle delay or provide progression to vehicles on the arterial, or both. However, meeting both of these criteria can be cumbersome, if not impossible, under high-demand situations. This research proposes a new design that consolidates common movements at three consecutive signalized intersections into strategic fixed locations along the arterial. The consolidation of common movements allows the intersections to cycle between only two critical phases, which, in turn, promotes shorter cycle lengths, lower delay, and better progression. This research tested the consolidated intersection concept by modeling a real-world site in microsimulation software and obtaining values for delay and travel time for multiple vehicle paths along the corridor and adjacent commercial developments in both existing and proposed conditions. With the exception of unsignalized right turns at the periphery of the study area, all non-displaced routes showed a reduction in travel time and delay. Additional research is needed to understand how additional travel through the commercial developments adjacent to the arterial may effect travel time and delay. Other expected benefits of the proposed design include a major reduction in conflict points, shorter pedestrian crossing and wait times, and the opportunity to provide pedestrian refuge areas in the median.

Improving the Design of Energy-Efficient Building Retrofitting

2018 ◽  
pp. 165-185
Author(s):  
Mari Aino Hukkalainen ◽  
Krzysztof Klobut ◽  
Tarja Mäkeläinen ◽  
Vanda Dimitriou ◽  
Dariusz Leszczyński
Keyword(s):  
Decision Making ◽  
Energy Efficient ◽  
Real Life ◽  
Multiple Criteria Decision Making ◽  
Energy System ◽  
Energy Performance ◽  
User Preference ◽  
Trade Offs ◽  
Practical Guidelines ◽  
Energy Simulations

Practical guidelines are presented for improved process for design and retrofitting of energy-efficient buildings, with an aim to integrate buildings better with the neighbourhood energy system, among others through energy matching. The chapter describes the role of energy simulations in an integrated building retrofitting process and how to select technologies for the retrofitting toward nearly zero energy building level. Feasibility of performing a holistic analysis of retrofitting options can be increased through the integration of BIM, well populated, and linked databases and a multi-criteria decision-making approach. Multiple-criteria decision-making methods aid taking into account a number of building energy performance and user-preference-related criteria and the trade-offs between the different criteria for each retrofitting option. The real-life viewpoints and benefits of utilising the developed methods and processes are discussed, especially from the Eastern European view.

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.

Mindfully Experimenting with IT

2014 ◽  
Vol 25 (2) ◽  
pp. 29-51 ◽  
Author(s):  
Robin S. Poston ◽  
William J. Kettinger
Keyword(s):  
Decision Making ◽  
Information Technology ◽  
Social Media ◽  
New Technology ◽  
Stakeholder Satisfaction ◽  
Media Technologies ◽  
New Information ◽  
Multi Level ◽  
Benefits And Costs

In many companies the process of new Information Technology (IT) identification and assessment lacks the rigor associated with experimentation. The realities of maintaining daily operations and the expense and expertise involved distract firms from conducting experiments. The authors explore cases of how companies introduce a new IT for the business use of digital social media. Because social media technologies are new, interest in its use is broad and diffused leading organizations to be unsure about how best to implement social media, prompting organizations to follow a mindful process of experimenting with these technologies. The cases illustrate that the extent of mindfulness influences how new technology implementations are introduced, supporting wider boundaries in assessments, richer interpretations of the IT's usefulness, multi-level foci concerning benefits and costs, persistence to continue exploration, and a greater use of fact-based decision-making. The authors observe that following a mindful introduction process reaps some of the benefits of experimentation, such as greater stakeholder satisfaction and organization-wide learning and understanding of the technology's potential.

Estimating Queue Length for Contraflow Left-Turn Lane Design at Signalized Intersections

2019 ◽  
Vol 145 (6) ◽  
pp. 04019020 ◽  
Author(s):  
Pan Liu ◽  
Jiaming Wu ◽  
Huaguo Zhou ◽  
Jie Bao ◽  
Zhao Yang
Keyword(s):  
Queue Length ◽  
Signalized Intersections ◽  
Left Turn
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