Scanning the Issue

Azim Eskandarian
2021 IEEE transactions on intelligent transportation systems (Print)  
Based on the application of transit data collection technologies, such as automated fare collection (AFC), global position system (GPS), smartphones, and face identification etc., this article reviewed how those data are utilized to observe passenger travel behavior, reschedule operation plans, and adjust policy decisions from the daily operations to the long-term network planning. A specific summary diagram is proposed to demonstrate the transit data applications and research topics. For each
more » ... ranch, the hot research direction and dimension shown as sub-branches are represented by reviewing the highly cited and the latest literature. The methodology and potential for each transit data application are summarized and a few promising implications are also discussed for the future. Trust in VANET: A Survey of Current Solutions and Future Research Opportunities R. Hussain, J. Lee, and S. Zeadally Trust management is one of the crucial requirements in vehicular networks and unlike other security requirements, data and entity trust affect the decision outcome of the applications in vehicular networks. Furthermore, trust and reputation are hard to achieve with the conventional cryptographic approaches that work very well for other security requirements such as authentication, confidentiality, and nonrepudiation, etc. Trust is the degree of certainty with which the received information is accepted and acted upon. In this article, the authors review, analyze, and compare some of the recently proposed trust establishment and management mechanisms in vehicular networks. Furthermore, they also discuss the weaknesses and inadequacies of existing trust establishment and management approaches when deployed in a vehicular network environment. Finally, they discuss some future challenges that will need to be addressed for trustworthy communications in vehicular networks. This article will help in identifying new avenues for future research related to trust management in vehicular networks. This survey summarizes the current state of the research on safety warnings under connected vehicle environments-from risk recognition algorithms, collision avoidance systems, dangerous event identification and notification methods, real-time safety warning system, and effects of various types of warning Bus bunching is an instability problem where busses operating on high-frequency transit lines arrive at stops in bunches. This work unveils that bus-following models can be used to design bus-to-bus cooperative control strategies and mitigate bunching. In a follow-the-leader two-bus system, bus-to-bus communication allows the driver of the following bus to observe (from a remote distance) the position and speed of the leading bus. The information transmitted from the leader is then used to control the speed of the follower to eliminate bunching. The simulations with empirical passenger data from the 9-km long 1-California line in San Francisco with about 50 arbitrary spaced stops, show bunching avoidance and improvements in terms of schedule reliability of bus services and delays. The control is robust, scalable in terms of transit network size, and thus easy to deploy by transit agencies to improve communication and guidance to drivers, and reduce costs. This article proposes a logic-based traffic flow control algorithm (LB-TFC) for integrated control of ramp metering installations and variable speed limits. LB-TFC estimates, for each control time step, the number of vehicles that should be held back or released by the control measures to avoid the capacity drop (maximizing the outflow of the bottleneck). Afterward, based on the resulting estimated number of vehicles, the VSLs and/or the RM rates are increased or decreased in a prespecified order. To avoid or reduce traffic breakdowns, the proposed controller (LB-TFC) anticipates the future evolution of the bottleneck density by using a feed-forward structure. As a result, the performance of the controller is very efficient and similar to the one obtained with an optimal controller while the implementation of the controller (with an almost instantaneous computation time) and the tuning of the parameters are easy. This article simulates, analyzes, and compares, for two case studies, the behavior of LB-TFC, an integrated control strategy for ramp metering installations and variable speed limits that was proposed and derivated in the first part of the work ("Part 1: Controller"). For the first case study, LB-TFC is compared with the optimal solution and with the MTFC + PI-ALINEA algorithm. For the second study (a stretch of the ring-road freeway SE-30 in Seville, Spain), data from ten different days have been used to simulate the performance of the considered controllers using real data for the afternoon peak period. For both case studies, LB-TFC provides a robust performance that, in most cases, is close to the optimal one and that improves the reduction in the total time spent (TTS) obtained with MTFC + PI-ALINEA. Moreover, this article studies the tuning of the control parameters and the advantages and disadvantages of LB-TFC.
doi:10.1109/tits.2021.3073191 fatcat:t2v7w23rmjex7eluksr46yo4v4