scholarly journals Estimation of Traffic Delay Due to U-Turns at Uncontrolled Medians: Case Study in Phnom Penh, Cambodia

2021 ◽  
Vol 14 (1) ◽  
pp. 118
Author(s):  
Maksat Omarov ◽  
Syuhaida Ismail ◽  
Wan Nurul Mardiah Wan Mohd Rani ◽  
Serdar Durdyev
Keyword(s):  
Traffic Congestion ◽  
High Volume ◽  
Control Measures ◽  
Delay Model ◽  
Average Delay ◽  
Phnom Penh ◽  
Suggested Technique ◽  
Traffic Performance ◽  
Traffic Delay

Lack of infrastructure capacity to the demand in mobility results in delays in traffic. U-turns restrict the movement of the opposing through-traffic during the maneuver, hence triggering delays. Significant delays can be observed, especially in high volume traffic, where U-turning is not restricted. Hence, it is imperative to study the delays incurred by the U-turning vehicles to assess their impacts on traffic congestion. This study thus proposes a quantitative method to estimate the aggregate and average delay per vehicle caused by U-turns at uncontrolled medians of urban roads. Traffic data were collected at a corridor where vehicles were allowed to U-turn on a four-lane divided mixed traffic urban road in Phnom Penh, Cambodia. The delay in the opposing lane of traffic was calculated by analyzing the data using a novel analytical method; a derivative of the Webster’s delay model. The results reveal that the suggested technique evaluates the caused delay with good accuracy. Excessive traffic delay and about three seconds delay per vehicle in the through-traffic of the opposite lane align well with the experienced delay at the site. The method can be used to assess the delay at straight corridor sections where U-turns are not restricted, understand the causes of the delay, and develop control measures for improved traffic performance.

scholarly journals Analysis of congestion cost at signalized intersection using Vissim 9 (Case study at Demak Ijo Intersection, Sleman)

2018 ◽  
Vol 181 ◽  
pp. 06001
Author(s):  
Noor Mahmudah ◽  
Rizkie Akbar ◽  
Muchlisin
Keyword(s):  
Traffic Congestion ◽  
Traffic Volume ◽  
Signalized Intersection ◽  
Average Delay ◽  
Traffic Condition ◽  
The Road ◽  
Congestion Cost ◽  
Road Capacity ◽  
High Traffic Volume

Due to imbalance of road capacity and traffic volume, so traffic congestion will be occurred either along the road and intersection. Demak Ijo intersection is one of signalized junction located in the western part of Yogyakarta with high traffic volume so traffic congestion is frequently occurred. The aim of this study is to analyze the performance of existing traffic condition and then estimate the congestion cost at signalized intersection by modeling (simulation) using Vissim 9. The analysis results show that existing traffic condition is in very bad condition (level F), average delay of 80 seconds, average queue length of 48.73 meters with congestion cost is about Rp. 2,830,336 per hour.

scholarly journals Performance and Stability Analyses of TCP Queue Based Computer Network

2020 ◽  
pp. 18-24
Author(s):  
Marvis Ijeaku Aririguzo ◽  
C. B. Mbachu
Keyword(s):  
Wireless Network ◽  
Traffic Congestion ◽  
Computer Network ◽  
Research Work ◽  
Step Function ◽  
Settling Time ◽  
Control Measures ◽  
Delay Model ◽  
Slow Response ◽  
Gain Margin

This research work centers on the performance and stability analysis of the TCP queue based network system. The TCP is a vital organ in every wireless network and due to the increasing reliance on the wireless network by most human activities, it has suffered from different forms of disturbances most especially traffic congestion which eventually results to data loss or total collapse of the network. Many works were reviewed on the TCP model and the methods proposed to improve the performance of the TCP networks. However, from the review, the TCP queue model was not examined based on its performance and reliability, to ascertain the real behavior of the system without the control measures. The step function time domain plot and bode frequency domain plot analyses measures were employed in this work.  From the simulation results, the TCP queue with time delay model recorded a 0% overshoot and settling time of 1.96e+03 seconds. With the high settling time the system performance will be very poor as a result of very slow response and it cannot support the recent high data traffic. Therefore, the system will not be able to solve the problem of congestion due to its slow response. The system also recorded a negative gain margin of -71.9dB, hence; the system is unstable and not reliable.

Modeling and control of variable approach lanes on an arterial road: a case study of Dalian

2018 ◽  
Vol 45 (11) ◽  
pp. 986-1003 ◽  
Author(s):  
Ronghan Yao ◽  
Xiaotong Zhang ◽  
Na Wu ◽  
Xianmin Song
Keyword(s):  
Traffic Congestion ◽  
Control Method ◽  
Time Of Day ◽  
Total Delay ◽  
Average Delay ◽  
Left Turn ◽  
Modeling And Control ◽  
Arterial Road ◽  
Variable Approach

Unbalanced directional traffic, which often exists at intersection approaches, is an important factor to induce traffic congestion on urban streets. Considering the settings of variable approach lanes, the presence of left-turn bays, and a variety of vehicle categories on an arterial road, an optimization model that minimizes the total delay is formulated and a control method that coordinates a variable sign and the corresponding signal group is put forward. To design the signal control scenarios with time of day, the procedure for using the proposed methodology is also presented in practice. To verify the given methodology, a case study is implemented using the field data and the four scenarios. The results reveal that the new methodology can better respond to the time-varying traffic flow at intersection approaches, and the provision of variable approach lanes and left-turn bays are helpful to reduce the average delay and enhance the average speed.

scholarly journals Parking Pricing vs. Congestion Pricing: A Macroscopic Analysis of their Impact on Traffic

2020 ◽  
Author(s):  
Manuel Jakob ◽  
Monica Menendez
Keyword(s):  
Traffic Congestion ◽  
Search Algorithm ◽  
Congestion Pricing ◽  
Central Area ◽  
Aggregated Data ◽  
Traffic Performance ◽  
Parking Pricing ◽  
Pricing Schemes ◽  
Parking Demand

As traffic congestion gets worse year by year in metropolitan areas, cities search for solutions to improve their traffic performance and reduce their environmental impacts. This paper focuses on parking pricing and congestion pricing and their short-term effects not only on traffic congestion but also on the potential revenue for a city. We develop an easy to implement multimodal macroscopic traffic and parking search model for a central area based on aggregated data at the network level. Our methodology allows us to analyze how introducing parking pricing inside a network, or a congestion toll combined with a park and ride (P+R) scheme can affect the drivers’ decision between entering the network by car (private vehicle) or using P+R instead. This decision directly influences the number of drivers using P+R, and this impacts, in turn, the traffic performance. Based on such analysis, a city can get valuable insights to evaluate whether congestion pricing is a necessity or if the traffic improvements resulting from implementing parking pricing strategies are sufficient when combined with P+R facilities. A search algorithm is used to find the best trade-off between the parking fees and the congestion toll. Any additional revenue collected through these schemes can then be used to improve public transport or the P+R facilities themselves. With minor data collection efforts and little computational costs compared to most existing parking and congestion pricing models, we illustrate our proposed framework in a case study of an area with a high parking demand for public parking spaces within the city of Zurich, Switzerland. Results show that parking pricing combined with P+R is indeed a viable option compared to congestion pricing for improving traffic performance, even if parking pricing schemes do not target all the drivers.

scholarly journals Operational and Safety Management at Intersections: Can the Turbo-Roundabout Be an Effective Alternative to Conventional Solutions?

2021 ◽  
Vol 13 (9) ◽  
pp. 5103
Author(s):  
Vincenzo Gallelli ◽  
Giusi Perri ◽  
Rosolino Vaiana
Keyword(s):  
Traffic Congestion ◽  
Safety Management ◽  
Environmental Benefits ◽  
Assessment Model ◽  
Pollutant Emission ◽  
Emission Rates ◽  
The European Union ◽  
European Union Policy ◽  
Union Policy

The European Union policy strategies on the sustainability of the transport system pursue the goals of maximizing safety and environmental benefits and reducing the severity and frequency of crashes, congestion, and pollutant emission rates. A common issue is the planning of the most effective solution for operational and safety management at intersections. In this study, an egg turbo roundabout is proposed as the alternative solution to a conventional roundabout in Southern Italy which suffers from traffic congestion. A comparative analysis is carried out using microsimulation techniques to investigate the safety effects and operational improvements of converting a traditional priority intersection into standard roundabout or turbo roundabout layout. In particular, the VISSIM software is used to explore the most relevant operational performance measures: queue length, travel times and delays. The lowest values of these measurements are recorded for the simulated turbo roundabout, thus making this scheme more appropriate in terms of operational performances. With regard to safety analysis, the Surrogate Safety Assessment Model (SSAM) is used to collect information on the predicted number of conflicts, the probability, and severity of the potential collisions. The results suggest that, for the specific case study, the safety levels of the standard roundabout and the turbo roundabout are approximately comparable.

scholarly journals Behavior of Traffic Congestion and Public Transport in Eight Large Cities in Latin America during the COVID-19 Pandemic

2021 ◽  
Vol 11 (10) ◽  
pp. 4703
Author(s):  
Renato Andara ◽  
Jesús Ortego-Osa ◽  
Melva Inés Gómez-Caicedo ◽  
Rodrigo Ramírez-Pisco ◽  
Luis Manuel Navas-Gracia ◽  
...  
Keyword(s):  
Latin American ◽  
Public Transport ◽  
Public Transportation ◽  
Traffic Congestion ◽  
Urban Transport ◽  
Control Measures ◽  
Johns Hopkins Hospital ◽  
Large Cities ◽  
Public Data ◽  
The Impact

This comparative study analyzes the impact of the COVID-19 pandemic on motorized mobility in eight large cities of five Latin American countries. Public institutions and private organizations have made public data available for a better understanding of the contagion process of the pandemic, its impact, and the effectiveness of the implemented health control measures. In this research, data from the IDB Invest Dashboard were used for traffic congestion as well as data from the Moovit© public transport platform. For the daily cases of COVID-19 contagion, those published by Johns Hopkins Hospital University were used. The analysis period corresponds from 9 March to 30 September 2020, approximately seven months. For each city, a descriptive statistical analysis of the loss and subsequent recovery of motorized mobility was carried out, evaluated in terms of traffic congestion and urban transport through the corresponding regression models. The recovery of traffic congestion occurs earlier and faster than that of urban transport since the latter depends on the control measures imposed in each city. Public transportation does not appear to have been a determining factor in the spread of the pandemic in Latin American cities.

scholarly journals Evaluation of the Applicability of the Ramp Metering to a Freeway Using Microsimulation: A Case Study in Riyadh, Saudi Arabia

2019 ◽  
Vol 9 (20) ◽  
pp. 4406
Author(s):  
Seongkwan Lee ◽  
Amr Shokri ◽  
Abdullah Al-Mansour
Keyword(s):  
Saudi Arabia ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Fixed Time ◽  
Ramp Metering ◽  
Traffic Data ◽  
Geometrical Data ◽  
Overall Performance ◽  
Length Reduction

Riyadh, the capital of Saudi Arabia, suffers from traffic congestion like other modern societies, during peak hours but also all day long, even without any incidents. To solve this horrible traffic congestion problem, various efforts have been made from the Active Traffic Management (ATM) aspect. Ramp metering (RM) is one of the representative methods of the ATM and has already proven its value in many locations worldwide. Unfortunately, RM has not yet been fully implemented in Saudi Arabia. This research aimed to assess the applicability of RM to a freeway in Riyadh using microsimulation. The widely known software VISSIM (PTV Planung Transport Verkehr AG, Germany, 1992) was chosen to compare the performances of various RM operating scenarios, such as fixedtime operation with different sub-scenarios and traffic-responsive operation using ALINEA (Asservissement Lineaire d’entree Autoroutiere) algorithm. For the simulations, this study targeted Makkah Road, one of the major freeways in Riyadh, and collected geometrical data and traffic data from that freeway. Analysis of four main scenarios and eight sub-scenarios, proved that overall performance of the fixed-time RM operation is generally good. The sub-scenario 4V3R of the fixed-time RM operation was the best in average queue length reduction. However, the traffic-responsive operation was best in average speed improvement.

A case study of noise pollution levels during the restrictions period due to COVID-19.

2021 ◽  
Vol 263 (6) ◽  
pp. 206-214
Author(s):  
David Montes-González ◽  
Juan Miguel Barrigón-Morillas ◽  
Ana Cristina Bejarano-Quintas ◽  
Manuel Parejo-Pizarro ◽  
Guillermo Rey-Gozalo ◽  
...  
Keyword(s):  
Noise Pollution ◽  
Urban Environments ◽  
Control Measures ◽  
Acoustic Measurements ◽  
Pollution Levels ◽  
The World ◽  
The Impact ◽  
The City

The pandemic of coronavirus disease (COVID-19) led to the need for drastic control measures around the world to reduce the impact on the health of the population. The confinement of people in their homes resulted in a significant reduction in human activity at every level (economic, social, industrial, etc.), which was reflected in a decrease in environmental pollution levels. Studying the evolution of parameters, such as the level of environmental noise caused by vehicle traffic in urban environments, makes it possible to assess the impact of this type of measure. This paper presents a case study of the acoustic situation in Cáceres (Spain) during the restriction period by means of long-term acoustic measurements at various points of the city.

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