Infrastructure Based Warning System for On-Coming Vehicles in Curvy Zones: Before and After Study

This paper describes a car access indication system called the Narrow Road Driving Support System. This system allows traffic moving in both directions to flow smoothly along roads with blind curves because it warns drivers of the existence of oncoming cars. The system has received an initial favorable reception from road users in the areas in which it is installed; however, only limited effects of the system have been investigated to date, primarily due to cost limitations. The authors of this paper reports on a study that measured the effect of the indication system quantitatively by monitoring changes in vehicle behavior and local road users’ perception before and after the system installation in Kochi Prefecture in Japan. In the survey before system installation, 86% of the respondents answered “yes” when questioned if they felt danger such as coming close to an oncoming car. In survey results after system installation, this percentage reduced to 43% of the respondents. Also, in the survey after system installation, there was a 27% increase in the number of respondents who answered, “I do not feel stress,” compared to the survey results before system installation. The results show the overall advantages and technical considerations of the use of this system on mountainous roads, particularly those with blind curves and passages that were only wide enough to permit one vehicle at a time. The installation of the system produced the following effects: drivers recognized the presence of an oncoming car, and thus could enter the defensive section at ease; when the system was operating, cars waited for oncoming cars at the turnout, and after any oncoming cars exited the section, other cars entered it, making traffic safer and smoother; and user satisfaction toward using the road was improved.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References; Tables;
  • Pagination: 11p
  • Monograph Title: ITS Connections: Saving Time. Saving Lives

Subject/Index Terms

Filing Info

  • Accession Number: 01142031
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 5 2009 7:06AM