Reliable Range of Individual Travel Time Information in Vehicular Ad Hoc Networks

Vehicular ad hoc mobile networks are promising platforms from which decentralized traffic information systems can be built. Considerable effort has been put into designing protocols and hardware for these systems. There are important intricacies in the kinds, quantities, and reliability of the data that will drive these systems, and detailed investigations of these data issue have received less attention. Even though a decentralized traffic information system in vehicular ad hoc networks has a number of benefits compared to a centralized system, such things as sampling errors for traffic information, differences between individual data and an average of all data, would exist as implicit weak points in this innovative system. In order to observe accuracy of individual travel time data, this study examined patterns of individual travel times collected from a hypothetical ad hoc system and 5-minute averages of travel time based on results from a simulation experiment. Paramics 5.2 was applied for the simulation experiment on a segment of the Baltimore-Washington Parkway in Maryland. The research concluded that most travel times during all traffic conditions were reliable to directly use as travel time information due to low variability except when travel time abruptly increases (high variability appeared in that situation). It is not sufficient or wise to remove high-valued data, however, because the underlying congestion state plays a large role in determining the reliability of the data. The study shows simple examples of data clustering that a more sophisticated filter might build on to minimize unreliable data.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 25p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01049553
  • Record Type: Publication
  • Report/Paper Numbers: 07-2605
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 7:18PM