RESIDING TIME DISTRIBUTIONS AND CALL HANDOVER TRAFFIC PERFORMANCE OF CELLS IN LEO IMOBILE SATELLITE

Author(s):  
V.G. Vaughn
Keyword(s):  
Author(s):  
Leila Azizi ◽  
Mohammed Hadi

The introduction of connected vehicles, connected and automated vehicles, and advanced infrastructure sensors will allow the collection of microscopic metrics that can be used for better estimation and prediction of traffic performance. This study examines the use of disturbance metrics in combination with the macroscopic metrics usually used for the estimation of traffic safety and mobility. The disturbance metrics used are the number of oscillations and a measure of disturbance durations in the time exposed time to collision. The study investigates using the disturbance metrics in data clustering for better off-line categorization of traffic states. In addition, the study uses machine-learning based classifiers for the recognition and prediction of the traffic state and safety in real-time operations. The study also demonstrates that the disturbance metrics investigated are significantly related to crashes. Thus, this study recommends the use of these metrics as part of decision tools that support the activation of transportation management strategies to reduce the probability of traffic breakdown, ease traffic disturbances, and reduce the probability of crashes.


Author(s):  
S M A Bin Al Islam ◽  
Mehrdad Tajalli ◽  
Rasool Mohebifard ◽  
Ali Hajbabaie

The effectiveness of adaptive signal control strategies depends on the level of traffic observability, which is defined as the ability of a signal controller to estimate traffic state from connected vehicle (CV), loop detector data, or both. This paper aims to quantify the effects of traffic observability on network-level performance, traffic progression, and travel time reliability, and to quantify those effects for vehicle classes and major and minor directions in an arterial corridor. Specifically, we incorporated loop detector and CV data into an adaptive signal controller and measured several mobility- and event-based performance metrics under different degrees of traffic observability (i.e., detector-only, CV-only, and CV and loop detector data) with various CV market penetration rates. A real-world arterial street of 10 intersections in Seattle, Washington was simulated in Vissim under peak hour traffic demand level with transit vehicles. The results showed that a 40% CV market share was required for the adaptive signal controller using only CV data to outperform signal control with only loop detector data. At the same market penetration rate, signal control with CV-only data resulted in the same traffic performance, progression quality, and travel time reliability as the signal control with CV and loop detector data. Therefore, the inclusion of loop detector data did not further improve traffic operations when the CV market share reached 40%. Integrating 10% of CV data with loop detector data in the adaptive signal control improved traffic performance and travel time reliability.


2015 ◽  
Vol 42 (7) ◽  
pp. 477-489 ◽  
Author(s):  
Ying Luo ◽  
M. Hadiuzzaman ◽  
Jie Fang ◽  
Tony Z. Qiu

Over the past few decades, several active traffic control methods have been proposed to improve freeway efficiency at bottleneck locations. Variable speed limit (VSL) is one of these effective controls. Previous studies have evaluated VSL control, but primarily during recurrent congestion only. This study focuses on evaluating the performance of VSL control for both recurrent and non-recurrent congestion. To assess the effectiveness of a previously proposed VSL control in a real-world situation, this study has three evaluation objectives: (1) examine the control performance when recurrent and (or) non-recurrent congestion occurs; (2) assess the effectiveness of the control when a queue encounters the VSL sign; and (3) consider the impact of system detection delay in VSL control. Comparative experiments for Whitemud Drive in Edmonton, Alberta, Canada, are simulated in the VISSIM platform, and traffic performance is compared among scenarios with and without control. The simulation results show that VSL improves mobility for both recurrent and non-recurrent congestion. The VSL control reduces total travel time, and improves total travel distance and total flow. Furthermore, it slows down the shockwave propagation speed, improves the average speed on most of the freeway segments, and reduces the duration of traffic recovery.


Author(s):  
Ramanujan Jagannathan ◽  
Joe G. Bared

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.


2016 ◽  
Vol 27 (04) ◽  
pp. 1650044 ◽  
Author(s):  
Jinlong Ma ◽  
Weizhan Han ◽  
Qing Guo ◽  
Shuai Zhang ◽  
Junfang Wang ◽  
...  

The traffic dynamics of multi-layer networks has become a hot research topic since many networks are comprised of two or more layers of subnetworks. Due to its low traffic capacity, the traditional shortest path routing (SPR) protocol is susceptible to congestion on two-layer complex networks. In this paper, we propose an efficient routing strategy named improved global awareness routing (IGAR) strategy which is based on the betweenness centrality of nodes in the two layers. With the proposed strategy, the routing paths can bypass hub nodes of both layers to enhance the transport efficiency. Simulation results show that the IGAR strategy can bring much better traffic capacity than the SPR and the global awareness routing (GAR) strategies. Because of the significantly improved traffic performance, this study is helpful to alleviate congestion of the two-layer complex networks.


LOGISTIK ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 12-18
Author(s):  
Hafidzsyah Alfiana ◽  
Adhi Purnomo

Commercial buildings in the Bassura Mall area (Jalan Jenderal Basuki Rahmat) have resulted in congestion in the area. Vehicles use road bodies to park their vehicles, sidewalks that are used as trading places by street vendors, and the position of the entrance / exit of Bassura Mall for four-wheeled vehicles that is not strategic. These things have caused the author to choose a location in the Bassura Mall area (Jalan Jenderal Basuki Rahmat), East Jakarta which is a local route, where East Jakarta as one of the big cities in the Special Capital Region of Jakarta also experiences high vehicle growth, p. This can be seen on roads in East Jakarta which often experience congestion during rush hour. The purpose of this research is to determine the traffic performance in the area. The method used in this research is direct observation method at the research location and field data collection in the form of parking volume data, pedestrian volume, vehicle volume entering / exiting Mall Bassura, traffic volume, and road performance. Observations were made on weekdays and holidays. The results of the analysis of the performance of the road sections show that the traffic volume on the roads around Mall Bassura is 32,433 SMP / hour on weekdays and 22,577 SMP / hour on holidays, with the service level index being in the F category on weekdays and holidays. Thus, the congestion factors mentioned above have resulted in a decrease in road capacity which has an impact on road performance.


Author(s):  
Anita Graser ◽  
Wolfgang Ponweiser ◽  
Melitta Dragaschnig ◽  
Norbert Brandle ◽  
Peter Widhalm
Keyword(s):  

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