scholarly journals Implementation of a Double Continuous Flow Intersection in Riyadh

2021 ◽  
Author(s):  
Kashif Bashir ◽  
Rana Imam ◽  
Ammar Sharan ◽  
Ala AlSoud
Keyword(s):  
Continuous Flow ◽  
Objective Assessment ◽  
Decision Makers ◽  
Average Delay ◽  
Continuous Growth ◽  
Traffic Conditions ◽  
Alternative Measures ◽  
Intersection Configuration ◽  
Alternative Designs ◽  
Intersection Design

The continuous growth of population in the capital, coupled with increased auto ownership and dependence has worsened traffic conditions on Riyadh's road network. Conventional methods to address this increased demand could be costly and insufficient. There has been greater interest in using alternative measures to improve the performance and safety characteristics on main corridors, particularly those that arrive at signalized intersections. Heavy left turning traffic at these intersections is one of the main causes for delays. Previous research has investigated several types of alternative designs termed "unconventional" arterial intersection designs that could minimize the effect of left turning traffic. This paper provides decision makers with an objective assessment on the efficiency of implementing an unconventional intersection design, the Double Continuous Flow Intersection (DCFI) configuration, to improve the operational and safety characteristics of an existing major signalized arterial intersection in Saudi Arabia. In this study, the Kingdom Hospital Intersection in Riyadh was selected, as it is one of the most congested intersections in Riyadh. Using the collected traffic data, the micro-simulation program VISSIM was used to analyze and compare the efficiency of both configurations. When compared to the existing conventional signalized intersection design, it was found that the proposed Double Continuous Flow Intersection (DCFI) unconventional intersection design decreased the average delay per vehicle by 99 seconds. The proposed Double Continuous Flow Intersection configuration also improved the Level of Service at the intersection from level F (152 sec/veh average delay) to level D (53 sec/veh average delay).

scholarly journals The Possibility for Implementing the Superstreet Unconventional Intersection Design in Jordan

2018 ◽  
Vol 46 (3) ◽  
pp. 122-128 ◽  
Author(s):  
Hana Naghawi ◽  
Alaa AlSoud ◽  
Taqwa AlHadidi
Keyword(s):  
Heavy Traffic ◽  
Objective Assessment ◽  
Simulation Software ◽  
Signalized Intersection ◽  
Microscopic Simulation ◽  
Average Delay ◽  
Policy Makers ◽  
Traffic Demand ◽  
Operational Characteristics ◽  
Intersection Design

This paper provides policy makers with an objective assessment on the possibility for implementing an unconventional arterial intersection design, the Superstreet, for improving safety and operational characteristics for an existing signalized intersection. The signalized intersection selected for analysis was Tabarbour, located in Amman, Jordan. Tabarbour intersection is considered one of the most significant signalized intersections in Amman. The intersection currently suffers from the following problems: long queues, delays and excessive emissions. SYNCHRO microscopic simulation software was used for signal optimization of the current conventional intersection. VISSIM microscopic simulation software was used to analyze and compare the Superstreet design to the conventional design. It was found that the proposed Superstreet reduced the average delay per vehicle by up to 87% and reduced the maximum queue length by almost 97%. This resulted in improving the level of service from F to C. Finally, five year future traffic demand analysis was performed; it was found that the Superstreet design didn’t perform as expected under heavy traffic volume.

Design and Performance Analysis of Pedestrian Crossing Facilities for Continuous Flow Intersections

2005 ◽  
Vol 1939 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Ramanujan Jagannathan ◽  
Joe G. Bared
Keyword(s):  
Continuous Flow ◽  
Level Of Service ◽  
Vehicular Traffic ◽  
Average Delay ◽  
Qualitative And Quantitative ◽  
Traffic Performance ◽  
Pedestrian Traffic ◽  
Pedestrian Level Of Service ◽  
And Performance ◽  
Pedestrian Crossing

Although concepts of the continuous flow intersection (CFI) have been around for approximately four decades, minimal or no literature describing studies that have analyzed pedestrian traffic performance at these intersections is available. Several studies have reported on the qualitative and quantitative benefits for the vehicular traffic performance of CFIs in comparison with the benefits for the vehicular traffic performance of conventional intersections but have provided minimal or no discussion about pedestrian traffic performance. As a novel intersection design, many important considerations are required to design pedestrian accesses and crossings at CFIs without compromising pedestrian safety and vehicular traffic performance. In this paper, the design methodologies for providing pedestrian access and related pedestrian signal timings are discussed. Modeling was conducted on three typical geometries for CFIs with base signal timings optimized for vehicular traffic performance. The results indicate an acceptable pedestrian level of service of B or C on the basis of the average delay per stop experienced by any pedestrian for pedestrian crossings at the typical CFI geometries modeled. All pedestrians served at the CFIs are accommodated within two cycles for a typical signal cycle length ranging from 60 to 100 s.

scholarly journals CLIMATE CHANGE KEY-CHALLENGES IN COASTAL ENGINEERING

2018 ◽  
pp. 33
Author(s):  
Iñigo J. Losada ◽  
Paula Camus ◽  
Alexandra Toimil ◽  
Antonio Espejo ◽  
Cristina Izaguirre
Keyword(s):  
Climate Change ◽  
Climate Change Impacts ◽  
Coastal Engineering ◽  
Coastal Communities ◽  
Decision Makers ◽  
Engineering Practice ◽  
Continuous Growth ◽  
Leading Role ◽  
Coastal Systems ◽  
Impacts Of Climate Change

Coastal engineers play a leading role in assessing climate change impacts in coastal and low-lying areas and in the design and implementation of adaptation solutions to build resilient coastal systems. Given the continuous growth of coastal communities and assets along the world coastlines, the need to protect and preserve natural and socioeconomic coastal systems and the escalating impacts of climate change (Wong et al. 2014), there is an urgent demand by decision makers for coastal engineering practice dealing with risk assessment and adaptation under high levels of uncertainty.

A New Continuous Flow Intersection for Urban Road: Architecture, Design, and Simulation

2012 ◽  
Vol 209-211 ◽  
pp. 677-682 ◽  
Author(s):  
Qiu Chen Liu ◽  
Lun Zhang ◽  
Wen Chen Yang
Keyword(s):  
Traffic Control ◽  
Continuous Flow ◽  
Left Turn ◽  
Urban Road ◽  
Traffic Efficiency ◽  
Traffic Conditions ◽  
Simulation Results ◽  
Low Efficiency ◽  
And Performance ◽  
Traffic Organization

In the light that heavy left-turn vehicles and oncoming vehicles conflict at conventional intersection(CI), leading to discontinuity and low efficiency of traffic flow, this paper presents a new continuous flow intersection(CFI) for urban roads. The geometry physical model and design principles of the CFI are illustrated and the CFI is designed from following three aspects: traffic space, traffic organization and traffic control. Experiments taking the CI and corresponding the CFI as the reseach objects are carried on, and performance of the proposed the CFI is validated via VISSIM. Extensive simulation results under five traffic conditions have demonstrated the potential of the proposed the CFI for improvement of traffic efficiency, and the applicability of the CFI in China is discussed considering the characteristics of domestic urban intersections and it indicates that the CFI could be applied to domestic suburb roads.

scholarly journals Service Differentiated and Adaptive CSMA/CA over IEEE 802.15.4 for Cyber-Physical Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Feng Xia ◽  
Jie Li ◽  
Ruonan Hao ◽  
Xiangjie Kong ◽  
Ruixia Gao
Keyword(s):  
Smart Grid ◽  
Ieee 802.15.4 ◽  
Cyber Physical Systems ◽  
Carrier Sense Multiple Access ◽  
Average Delay ◽  
Physical Systems ◽  
Traffic Conditions ◽  
Parameter Configuration ◽  
Grid Applications

Cyber-Physical Systems (CPS) that collect, exchange, manage information, and coordinate actions are an integral part of the Smart Grid. In addition, Quality of Service (QoS) provisioning in CPS, especially in the wireless sensor/actuator networks, plays an essential role in Smart Grid applications. IEEE 802.15.4, which is one of the most widely used communication protocols in this area, still needs to be improved to meet multiple QoS requirements. This is because IEEE 802.15.4 slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) employs static parameter configuration without supporting differentiated services and network self-adaptivity. To address this issue, this paper proposes a priority-based Service Differentiated and Adaptive CSMA/CA (SDA-CSMA/CA) algorithm to provide differentiated QoS for various Smart Grid applications as well as dynamically initialize backoff exponent according to traffic conditions. Simulation results demonstrate that the proposed SDA-CSMA/CA scheme significantly outperforms the IEEE 802.15.4 slotted CSMA/CA in terms of effective data rate, packet loss rate, and average delay.

scholarly journals Rapid, risk-based levee design framework for greater risk reduction at lower cost than standards-based design

2021 ◽  
Author(s):  
David Johnson ◽  
Jingya Wang ◽  
Nathan Geldner ◽  
Andrew Zehr
Keyword(s):  
Residual Risk ◽  
Decision Makers ◽  
Climate Change Scenarios ◽  
Total System ◽  
Design Paradigm ◽  
The Cost ◽  
System Configurations ◽  
Coastal Louisiana ◽  
Alternative Designs ◽  
Similar Cost

Abstract Standards-based levee design aims to protect against events with specific probabilities, for example eliminating overtopping from a “1-in-100-year” storm surge. This allows levee segments to be analyzed independently but ignores interior dynamics and overall risk. We present and implement a framework for calculating optimal risk-informed design heights. Using this design paradigm and multi-objective evolutionary algorithms, we identify levee and floodwall design heights that minimize the total system cost and expected flood losses over 50 years. With our model, decision makers may feasibly evaluate hundreds or thousands of alternative designs. Comparing to the existing design elevations of the Larose to Golden Meadow Hurricane Protection Project in coastal Louisiana, over multiple climate change scenarios, we identify system configurations of similar cost that reduce the expected value of discounted residual risk of 26–73% ($8–85 million). We also achieve the same residual risk at 90–97% of the cost of the existing system (saving $19–73 million).

On the Aggregation of Preferences in Engineering Design

2001 ◽  
Author(s):  
Beth Allen
Keyword(s):  
Engineering Design ◽  
Collaborative Design ◽  
Design Space ◽  
Decision Makers ◽  
Impossibility Theorem ◽  
Von Neumann ◽  
Aggregation Of Preferences ◽  
Ordinal Preferences ◽  
Additive Separability ◽  
Alternative Designs

Abstract This paper considers the possibility for aggregation of preferences in engineering design. Arrow’s Impossibility Theorem applies to the aggregation of individuals’ (ordinal) preferences defined over a finite number of alternative designs. However, when the design space is infinite and when all individuals have monotone preferences or have von Neumann-Morgenstern (cardinal) utilities defined over lotteries, possibility results are available. Alternative axiomatic frameworks lead to additional aggregation procedures for cardinal utilities. For these results about collaborative design, aggregation occurs with respect to decision makers and not attributes, although some of the possibility results preserve additive separability in attributes.

Enhanced Genetic Algorithm for Signal-Timing Optimization of Oversaturated Intersections

2000 ◽  
Vol 1727 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Byungkyu “Brian” Park ◽  
Carroll J. Messer ◽  
Thomas Urbanik
Keyword(s):  
Genetic Algorithm ◽  
Operating Conditions ◽  
Throughput Maximization ◽  
Signal Timing ◽  
Timing Optimization ◽  
Average Delay ◽  
Delay Minimization ◽  
Traffic Conditions ◽  
Cycle Lengths ◽  
Oversaturated Intersections

Enhancements were provided to a previously developed genetic algorithm (GA) for traffic signal optimization for oversaturated traffic conditions. A broader range of optimization strategies was provided to include modified delay minimization with a penalty function and throughput maximization. These were added to the initial delay minimization strategy and were further extended to cover all operating conditions. The enhanced program was evaluated at different intersection spacings. The optimization strategies were evaluated and compared with their counterpart from TRANSYT-7F, version 8.1. A microscopic stochastic simulation program, CORSIM, was used as the unbiased evaluator. Hypothesis testing indicated that the GA-based program with average delay minimization produced a superior signal-timing plan compared with those produced by other GA strategies and the TRANSYT-7F program in terms of queue time. It was also found from the experiments that TRANSYT-7F tended to select longer cycle lengths than the GA program to reduce random plus oversaturation delay.

scholarly journals Minimizing the Average Delay at Intersections via Presignals and Speed Control

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mina Ghanbarikarekani ◽  
Xiaobo Qu ◽  
Michelle Zeibots ◽  
Weiwei Qi
Keyword(s):  
Transportation Systems ◽  
Urban Transport ◽  
Transport Systems ◽  
Average Delay ◽  
Public And Private ◽  
Additional Signal ◽  
Traffic Conditions ◽  
Private Transportation ◽  
Overall Efficiency ◽  
Set Up

Urban intersections have been well recognized as bottlenecks of urban transport systems. It is thus important to propose and implement strategies for increasing the efficiency of public and private transportation systems as a whole. In order to achieve this goal, an additional signal could be set up near the intersection to give priority to buses through stopping vehicles in advance of the main intersection as a presignal. It has been increasingly popular in urban cities. While presignals indeed reduce the average delay per traveler, they cause extra stops of private vehicles, which might compromise the overall efficiency, safety, and sustainability. This paper aims to propose a model to improve presignals by reducing the vehicles’ number of stops behind the presignals. By applying the method, vehicles would be able to adjust their speed based on traffic conditions as well as buses’ speed and approach. Numerical analyses have been conducted to determine the conditions required for implementing this method.

The role of science in MPA establishment in California: a personal perspective

2012 ◽  
Vol 39 (3) ◽  
pp. 195-198 ◽  
Author(s):  
RAY HILBORN
Keyword(s):  
Protected Areas ◽  
Adaptive Management ◽  
Marine Protected Areas ◽  
Biological Diversity ◽  
Experimental Tests ◽  
Decision Makers ◽  
Convention On Biological Diversity ◽  
Personal Perspective ◽  
Alternative Designs

SummaryCalifornia has now largely completed a process for establishing marine protected areas (MPAs) that may be considered a model for other jurisdictions seeking to meet obligations under the Convention on Biological Diversity. In the Californian process, a team of scientists established guidelines on the size and spacing of MPAs, as well as requirements for habitat representation and replication. The final outcomes, in terms of proportion of the coast encompassed by MPAs and the distribution and sizes of MPAs, were largely a result of decisions taken by the advisory scientists, rather than by the designated decision makers. Future legislation must recognize the uncertainties associated with benefits of MPAs and specifically allow for adaptive management including explicit experimental tests of uncertainties. The science team should define at the outset the major uncertainties about impacts, and deliberate experimentation and adaptive management should be essential parts of each design. Future legislation should be much more specific about the objectives of the MPAs and specify the percentage of the area that should be set aside as MPAs. Finally, quantitative models rather than guidelines should be used to evaluate the consequences of alternative designs.

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