Browsing by Author "Ibrahim, Umair"
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Item Development and Field Demonstration of DSRC Based V2V-Assisted V2I Traffic Information System for the Work Zone(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-06) Maitipe, Buddhika; Ibrahim, Umair; Hayee, M. ImranThis report describes the architecture, functionality and the field demonstration results of a newly developed DSRC based V2I work zone traffic information system with V2V assistance. The developed system can automatically acquire important work zone travel information, e.g., the travel time (TT) and the starting location of congestion (SLoC), and relay them back to the drivers approaching the congestion site. Such information can help drivers in making informed decisions on route choice and/or preparing for upcoming congestion. Previously, we designed such a system using DSRC based V2I-only communication, which could not handle longer congestion lengths and the message broadcast range was also very limited. Our current system, on the other hand, can achieve much longer broadcast range (up to a few tens of kms), and can handle much longer congestion coverage length (up to a few kms) by incorporating DSRC based V2I communication with V2V assistance. The new system is also portable and uses only one RSU, which can acquire traffic data by engaging the vehicles traveling on the roadside whether within or outside of its direct wireless access range. From the traffic data, it estimates important traffic parameters, i.e., TT and SLoC, and periodically broadcasts them back to the vehicles approaching the congestion well before they enter the congested area. The results from the field demonstration have indicated that new system can adapt to dynamically changing work zone traffic environments and can handle much longer congestion lengths as compared to the previous system using V2I-only communication without V2V assistance.Item Development of a traffic information system using ad-hoc control and DSRC based V2V communication(2013-09) Ibrahim, UmairA lane closure can significantly reduce the vehicles speed through the freeway bottleneck, resulting in the congestion buildup. As the queue length grows past the posted static warning signs in the congested zone surprising many drivers which can greatly increase the probability of rear end vehicle crash. In such circumstances, a real time traffic safety information system could help minimize rear end collisions. Current traffic information systems use radio, internet, or cellular communication to convey the information of congestion to the drivers. This information is generated using static sensor probes that often give a rough estimate of traffic parameters e.g., end-of-queue location, and travel time. Additionally, the update to the traffic data occurs quite infrequently and sometimes is obsolete by the time when a driver receives it. However, these systems suffer from issues such as latency and reliance on third party and/or dedicated infrastructure support.This paper presents architecture, functionality, and field evaluation of a newly developed real-time traffic information system using DSRC based V2V communication without needing any roadside infrastructure support. The developed system utilizes an ad-hoc host vehicle acting as central control from among the DSRC equipped vehicles present on the road to dynamically acquire important traffic parameters such as starting and ending locations of congestion, and travel time. Furthermore, it provides useful traffic alerts to DSRC equipped vehicles to improve drivers' situational awareness. The algorithm designed for the system makes it fully adaptable to any congestion scenario whether due to a work zone or an incident, or due to regular rush hour traffic. The developed system is well suited for operational deployment in future, particularly during the initial phase of the DSRC market penetration, because it incorporates DSRC equipped programmable changeable message signs (PCMSs) to convey the warning messages to non-DSRC equipped vehicles. Furthermore, a rigorous analysis has been conducted to investigate the minimum DSRC market penetration rate needed for the developed system to successfully acquire and disseminate TT and SLoC for the work zone. The results of this analysis suggest that a market penetration rate ranging from 20% to 35% is needed for the system to reliably work.Item Development of Hybrid DSRC-PCMS Information Systems for Snowplow Operations and Work Zones(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2013-02) Ibrahim, Umair; Hayee, M. ImranThe future deployment of dedicated short range communication (DSRC) technology requires that DSRC-based applications are integrated with existing traffic management techniques so that non-DSRC-equipped vehicles at the early stage of DSRC deployment can also reap the potential benefits of DSRC technology. We have successfully developed and field demonstrated a hybrid traffic-information system combining DSRC technology and portable changeable message signs (PCMS) for work zone environment to improve traffic mobility, and thereby, driver safety. The developed system uses DSRC-based V2I and V2V communication to acquire travel safety parameters such as travel time (TT) and starting location of congestion (SLoC), and disseminate these parameters to both DSRC-equipped vehicles and DSRC-equipped PCMSs, which are strategically placed alongside the road. Using the DSRC-PCMS interface designed for this purpose, PCMSs can receive these travel safety parameters from nearby DSRC-equipped vehicles on the road via DSRC-based V2V communication, and display them for the drivers of the vehicles lacking DSRC capability. Such a system can be useful for an early stage of DSRC deployment when the DSRC market penetration is low. Additionally, a rigorous analysis has been conducted to investigate the minimum DSRC market penetration rate needed for successful functionality of the developed system with respect to both acquisition and dissemination of TT and SLoC. Using realistic traffic flow model, guidelines are developed to estimate a minimum DSRC penetration rate needed to deploy the developed system for a variety of traffic scenarios on a given work zone road.