scholarly journals DEVELOPMENT AND EVALUATION OF A QUICK METHOD FOR OPTIMIZING A SPACE AND SIGNAL TIMING PLAN FOR ISOLATED SIGNALIZED INTERSECTIONS

Transport ◽  
2020 ◽  
Vol 0 (0) ◽  
pp. 1-12
Author(s):  
Nedal Ratrout ◽  
Khaled Assi
Keyword(s):  
Signalized Intersections ◽  
Signal Timing ◽  
Quick Method ◽  
Traffic Demand ◽  
Optimization Software ◽  
Space And Time ◽  
Plan Optimization ◽  
New Models ◽  
Volume Characteristics

One major cause of congestion at intersections is the fluctuation of traffic demand during the day. This phenomenon necessitates developing new models that can be used to enhance the performance of signalized intersections. We suggest a quick procedure for optimizing signal timing plans after identifying the best phasing scheme and selecting optimal lane allocation (space optimization) for any volume characteristics during the day at a typical four-leg intersection. The main contribution of this study is developing a method for collectively optimizing a signal-timing plan, intersection space, and phasing scheme. TRANSYT-7F, SYNCHRO and HCS2010 were used to assess the developed models in a case study. It was found that regardless of the optimization software used for timing-plan optimization, optimizing both space and timing plan together produce significant reductions in average intersection delay compared to optimizing only the timing plan. Furthermore, this study showed that the developed model, which optimizes space and time, consistently provided better results in terms of average intersection delay compared to TRANSYT-7F, SYNCHRO and HCS2010 in the case study.

Developing Guidelines for Implementing Transit Signal Priority and Freight Signal Priority Using Simulation Modeling and a Decision Tree Algorithm

2021 ◽  
pp. 036119812110575
Author(s):  
Shahadat Iqbal ◽  
Taraneh Ardalan ◽  
Mohammed Hadi ◽  
Evangelos Kaisar
Keyword(s):  
Decision Tree ◽  
Signal Control ◽  
Signal Timing ◽  
Transit Signal Priority ◽  
Decision Tree Algorithm ◽  
Tree Algorithm ◽  
Traffic Demand ◽  
Capacity Ratio ◽  
The Impact

Transit signal priority (TSP) and freight signal priority (FSP) allow transportation agencies to prioritize signal service allocations considering the priority of vehicles and, potentially, decrease the impact signal control has on them. However, there have been no studies to develop guidelines for implementing signal control considering both TSP and FSP. This paper reports on a study conducted to provide such guidelines that employed a literature review, a simulation study, and a decision tree algorithm based on the simulation results. The guideline developed provides recommendations in accordance with the signal timing slack time, the proportion of major to minor street hourly volume, hourly truck volume per lane for the major street, hourly truck volume per lane for the minor street, the proportion of major to minor street hourly truck volume, the proportion of major to minor street hourly bus volume, the volume-to-capacity ratio for the major street, and the volume-to-capacity ratio for the minor street. The guideline developed was validated by implementing it for a case study facility. The validation result showed that the guideline works correctly for both high and low traffic demand.

scholarly journals Improving SCATS Operation during Congestion Periods Using Internal/External Traffic Metering Strategy

2016 ◽  
Vol 28 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Shahriar Afandizadeh Zargari ◽  
Nazli Dehghani ◽  
Hamid Mirzahossein ◽  
Masoud Hamedi
Keyword(s):  
Optimal Level ◽  
Signalized Intersections ◽  
Signal Timing ◽  
Test Case ◽  
Effective Strategies ◽  
Dynamic Setting ◽  
Average Travel Time ◽  
Traffic Metering ◽  
Queue Lengths

Traffic metering is one of the effective strategies of preventing gridlock at urban signalized intersections during oversaturated conditions. This strategy could be implemented by adjusting signal timing schemes of the connected intersections of congested network in dynamic setting. This paper demonstrates the benefits of internal/external traffic metering strategy on a real case study in Tehran, the capital of Iran. For this purpose, the model outputs have been considered as input to set of SCATS scenarios for signal timing. In each test case the system is forced to use plans obtained from the model instead of using common built-in plans that had been used before, and the performance is measured using the VISSIM simulator to show differences. The results show significant improvement in network average travel time when using internal/external traffic metering strategy. Additionally, the average queue lengths are maintained near the optimal level since the model utilizes upstream arterial capacity.

scholarly journals An Innovative Signal Timing Strategy for Implementing Contraflow Left-Turn Lanes at Signalized Intersections with Split Phasing

2021 ◽  
Vol 13 (11) ◽  
pp. 6307
Author(s):  
Rongwei Guo ◽  
Jinli Liu ◽  
Yi Qi
Keyword(s):  
Traffic Simulation ◽  
Design Procedure ◽  
Signalized Intersections ◽  
Signal Timing ◽  
Current Signal ◽  
Clearance Time ◽  
Left Turn ◽  
Simulation Based ◽  
Time Requirements

Contraflow Left-Turn Lanes (CLLs) have the potential of being a solution for mitigating congestions at signalized intersections where split phasing is recommended or required. However, the current signal timing strategy for the intersections with CLLs cannot be directly applied at the signalized intersections with split phasing (SIWSP). To address this problem, this study proposed an innovative signal timing strategy, which is referred to as Counterclockwise Split Phasing (CSP) signal timing, for implementing the CLLs at the SIWSPs. A traffic simulation-based case study was conducted and the results indicate that, by using the proposed CSP signal timing plan, CLLs can be implemented at the SIWSP and can significantly reduce the traffic congestions caused by the high left-turn demand at this type of intersection. In addition, since the proposed CSP signal timing design procedure has fully considered the clearance time requirements for the left-turn vehicles on the CLLs, the risk associated with the use of CLLs can be controlled which makes it safe to use this innovative intersection design at SIWSPs.

scholarly journals Towards Sustainable Mobility? The Influence of the COVID-19 Pandemic on Romanian Mobile Citizens in Spain

2021 ◽  
Vol 13 (7) ◽  
pp. 4023
Author(s):  
Silvia Marcu
Keyword(s):  
Sustainable Development Goals ◽  
Human Mobility ◽  
Sustainable Mobility ◽  
The Sustainable Development ◽  
New Models ◽  
Challenges And Opportunities ◽  
Development Goals ◽  
Depth Interviews

Using the case study of Romanians in Spain, this article highlights how the COVID-19 crisis presents both challenges and opportunities when it comes to human mobility and sustainability. Drawing on in-depth interviews with mobile people during the period of lockdown and circulation restrictions, and in accordance with the objectives of the Sustainable Development Goals (SDGs), the paper advances and contributes to the relevance of sustainability and its impact on people’s mobility in the context of the COVID-19 pandemic. I argue that even in the midst of the crisis, sustainable ways may be found to promote and protect human mobility. The paper raises the way sustainability acts as a driver, gains relevance and influence, and contributes to the creation of new models of resilient mobility in times of crisis. The conclusions defend the respect for the SDGs regarding human mobility and emphasise the role of people on the move as sustainable actors learning to overcome distance and the barriers to their mobility during the pandemic.

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.

scholarly journals Design of Signal Timing Plan for Urban Signalized Networks including Left Turn Prohibition

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Qinrui Tang ◽  
Bernhard Friedrich
Keyword(s):  
Travel Time ◽  
Treatment Options ◽  
User Equilibrium ◽  
Signal Timing ◽  
Stochastic User Equilibrium ◽  
Left Turn ◽  
Traffic Demand ◽  
Total Travel Time ◽  
Left Turns ◽  
Demand Patterns

Urban road networks may benefit from left turn prohibition at signalized intersections regarding capacity, for particular traffic demand patterns. The objective of this paper is to propose a method for minimizing the total travel time by prohibiting left turns at intersections. With the flows obtained from the stochastic user equilibrium model, we were able to derive the stage generation, stage sequence, cycle length, and the green durations using a stage-based method which can handle the case that stages are sharing movements. The final output is a list of the prohibited left turns in the network and a new signal timing plan for every intersection. The optimal list of prohibited left turns was found using a genetic algorithm, and a combination of several algorithms was employed for the signal timing plan. The results show that left turn prohibition may lead to travel time reduction. Therefore, when designing a signal timing plan, left turn prohibition should be considered on a par with other left turn treatment options.

scholarly journals IMPACT OF MEMENTO VALUE ON THE PERCEPTION OF CULTURAL HERITAGE: CASE STUDY OF THE MODERN MOVEMENT AND DIALECT OF KAUNAS / ATMINTIES VERTĖ SUVOKIANT KULTŪROS PAVELDĄ: MODERNIZMO JUDĖJIMO IR JO KAUNIETIŠKOJO DIALEKTO ATVEJO TYRIMAS

2018 ◽  
Vol 10 (0) ◽  
pp. 1-7
Author(s):  
Huriye Armagan DOGAN
Keyword(s):  
Built Environment ◽  
Cultural Heritage ◽  
Empirical Approach ◽  
The Past ◽  
Space And Time ◽  
The Impact ◽  
Modern Movement

Memento value in heritage is one of the most essential characteristics facilitating the association between the environment and its users, by connecting structures with space and time, moreover, it helps people to identify their surroundings. However, the emergence of the Modern Movement in the architectural sphere disrupted the reflection of memory and symbols which serve to root the society in its language. Furthermore, it generated an approach that stood against the practice of referring to the past and tradition, which led to the built environment becoming homogeneous and deprived of memento value. This paper focuses on the impact of memento value on the perception and evaluation of cultural heritage. Furthermore, it investigates the notions which are perceived to influence the appraisal of cultural heritage by applying them to the Kaunas dialect of the Modern Movement with an empirical approach.

Evaluating the Operational Efficiency of Two Versions of Super Diverging Diamond Interchange Design: A Case Study in Denver, Colorado

2021 ◽  
pp. 036119812110372
Author(s):  
Muhammad Tahmidul Haq ◽  
Amirarsalan Mehrara Molan ◽  
Khaled Ksaibati
Keyword(s):  
Research Effort ◽  
Traffic Signals ◽  
Operational Efficiency ◽  
Traffic Demand ◽  
Operational Analysis ◽  
Signal Coordination ◽  
Traffic Volumes ◽  
Microsimulation Models ◽  
Better Than

This paper aims to advance the current research on the new super diverging diamond interchange (super DDI) design by evaluating the operational efficiency using real-world locations. As part of a comprehensive research effort on improving the performance of failing service interchanges in the mountain-plains region, the study identified three interchanges (Interstate 225 and Mississippi Avenue, Interstate 25 and 120th Avenue, and Interstate 25 and Hampden Avenue) at Denver, Colorado as the potential candidates to model for future retrofit. Four interchange designs (i.e., existing CDI [conventional diamond interchange], DDI, super DDI-1, and super DDI-2) were tested in this study. The operational analysis was conducted using VISSIM and Synchro. Several microsimulation models (120 scenarios with 600 runs in total) were created with three peak hours (a.m., noon, and p.m.) for existing (the year 2020) and projected (the year 2030) traffic volumes. The study considered two simulation networks: (1) when no adjacent traffic signal exists, to determine how the four interchange designs would perform if there were no adjacent signals or they were far away from the interchange; and (2) when there are two adjacent traffic signals, to evaluate the performance of the four interchanges in a bigger corridor with signal coordination needed. An important finding is that super DDI designs outperformed DDI with adjacent signals and higher traffic demand, while DDI performed similarly to or sometimes insignificantly better than super DDI if no adjacent intersections were located in the vicinity and if the demand was lower than the DDI’s capacity.

scholarly journals Road-safety recognition and network equilibrium with perceived route-choice sets

2019 ◽  
Vol 1 (2) ◽  
pp. 126-134
Author(s):  
Mao-sheng Li ◽  
He-lai Huang
Keyword(s):  
Convex Combination ◽  
Route Choice ◽  
User Equilibrium ◽  
Equilibrium Analysis ◽  
Combination Method ◽  
Crash Frequency ◽  
Traffic Demand ◽  
Additional Costs ◽  
Choice Set

Abstract Safety is regarded as the second basic need in Maslow’s hierarchy of needs (1943), and safety recognition and circumvention behaviour in the route-choice decision-making process should therefore be accommodated in network-traffic equilibrium analysis frameworks. This paper proposes a framework by which crash frequency, forecasted using the safety-analysis method or compiled from historical data for intersections, is used to measure the safety consciousness of drivers. Drivers are then classified into different groups according to their acceptable-risk thresholds, and each group has its own route-choice set. Decision behaviour whereby drivers are willing to bear additional costs in order to circumvent travel risk is incorporated into the variational inequality model based on the user equilibrium in the perceived route-choice set (UE-PRCS), which is an extension of Wardrop’s first principle. The Frank–Wolfe algorithm, based on the convex combination method, is employed to obtain the solution. A small road network is used as a case study to illustrate the proposed framework, incorporating risk recognition and circumvention behaviour under different combinations of traffic demand and risk-sensitivity group ratio. The results show that the standard user equilibrium is a special case of the UE-PRCS, but that the UE traffic state is more common than the UE-PRCS under different parameters.

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