Browsing by Subject "Vehicle to roadside communications"

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    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. Imran
    This 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.
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    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. Imran
    The 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.