This report describes the results of a before-and-after study to evaluate the effectiveness of dynamic sign systems in alerting motorists to the presence of narrow bridges on two lane rural highways. Vehicle speed and lateral placement (perpendicular distance to roadway centerline) data were gathered for each of the dynamic sign systems tested as well as for the base (before) passive system as drivers approached and crossed the narrow bridge. These data were used as the primary measures of effectiveness for determining the ability of each of the sign systems to increase safety and improve driver awareness of potential hazards. A roadside survey was independently conducted by the State of Maine to determine the public reaction to the dynamic sign systems. The results of the survey were made available to the authors and are discussed in this report. Four sign systems were examined under both day and night conditions. These included flashing beacons, strobe lights, and two neon message signs. Two additional sign systems involving bridge lights were examined at night only. The sign systems were dynamic in the sense that they were activated by traffic approaching the bridge. The experiment was conducted at the Federal Highway Administration Maine Facility located on U.S. Route 2. Results showed no substantial and consistent differences between the existing the dynamic sign systems in terms of the speed and lateral placement measures. It may have been that these measures were not sensitive to or good indicators of the possible change in driver behaviour to the new signs. The roadside survey provided additional driver awareness measures for determining the safety benefits of the new sign systems but also did not reveal any important improvements. /Author/

  • Supplemental Notes:
    • Sponsored by the Federal Highway Administration.
  • Corporate Authors:

    Transportation Systems Center

    55 Broadway, Kendall Square
    Cambridge, MA  United States  02142
  • Authors:
    • Koziol Jr, J S
    • Mengert, P H
  • Publication Date: 1978-9

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 78 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00188213
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: DOT-TSC-FHWA-78-3 Final Rpt.
  • Files: TRIS, USDOT
  • Created Date: Mar 14 1979 12:00AM