A STUDY TO IMPROVE THE SAFETY OF EXPRESSWAYS BY DESIRABLE COMBINATIONS OF GEOMETRIC ALIGNMENTS

Most of the information that drivers require is acquired through their eyes. Therefore, for safe high-speed driving, it is important to obtain accurate visual information about the road and its geometric features. There are, however, some cases in which the visual information is perceived incorrectly by drivers and this is one cause of accidents when complicated alignments are used. Two experiments have been conducted to determine which combinations of horizontal and/or vertical alignments would cause such visual illusions to be experienced on expressways. First, expressway patrol drivers who drive every day over a certain section of an expressway were questioned to determine if they experienced such illusions while they were driving there. Secondly, several ordinary drivers were asked to report everything that they saw while they were driving the same sections of the expressway. The drivers were being recorded continuously by a video camera. Analyzing the relationships between the locations and illusions, and the combinations of horizontal and/or vertical alignments, a few facts were derived in regard to alignments and a certain type of illusion. An attempt was also made to determine the relationship between the occurrence of visual illusions and traffic accidents by surveying traffic accident records. However, it does not seem that there is any significant correlation between the occurrence of illusions and the type and the likelihood of traffic accidents.

• Record URL:
  http://onlinepubs.trb.org/onlinepubs/circulars/ec003/toc.pdf
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• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00978515
• Supplemental Notes:
  • The proceedings have been edited by the Texas Transportation Institute, Texas A&M University System, College Station, Texas. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • MORI, Y
  • Kurihara, M
  • Hayama, A
  • Ohkuma, S
• Conference:
  • International Symposium on Highway Geometric Design Practices
  • Location: Boston, Massachusetts
  • Date: 1995-8-30 to 1995-9-1
• Publication Date: 1998-1

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 23:1-12
• Serial:
  • Transportation Research Circular
  • Issue Number: E-C003
  • Publisher: Transportation Research Board
  • ISSN: 0097-8515

Subject/Index Terms

• TRT Terms: Alignment; Crash records; Expressways; Field studies; Geometric design; Highway safety; Traffic crashes; Visual perception
• Uncontrolled Terms: Horizontal alignment; Vertical alignment
• Subject Areas: Design; Highways; Planning and Forecasting; Safety and Human Factors; I21: Planning of Transport Infrastructure; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 00794680
• Record Type: Publication
• Report/Paper Numbers: E-C003
• Files: TRIS, TRB, ATRI
• Created Date: Jun 12 2000 12:00AM