THE USE OF SKEWED SPEED DISTRIBUTIONS TO LOCATE POINTS OF HIGH ACCIDENT POTENTIAL ON LOW VOLUME TWO-LANE RURAL HIGHWAYS

The objective of this research was to determine if a correlation exists between skewed speed distributions and points of high accident potential. To achieve the objective, spot speeds and accident data were studied at twelve sites during daytime hours and five sites during nighttime hours. All sites were on rural two-lane highways. A perception-speed concept of driver responses to a potential accident situation were developed. This concept examined a driver's reaction to a potential hazard based on his personal perception of the hazard and on the forces he had at his disposal to avoid the hazard. It was shown that where a driver had a particular difficulty in perceiving the hazard or where he perceived the hazard incorrectly, the probability of an accident occurring was greater. The findings of this research tend to support the hypothesis made in the development of this concept. It was found that sites having high accident frequency histories also exhibited skewed speed-frequency distributions. Sites having low or no accident histories exhibited normal speed-frequency distributions. The comparison of the day and night data and directional data found that while certain parameters such as mean speed and deviation did change, the relative shape of the frequency distribution curve did not if perceptual accuracy did not change. This research proposes that the test and analysis procedure developed should be employed to find areas of perceptual problems prior to the occurrence of accidents and to test the effectiveness of warning or corrective measures.

• Corporate Authors:

  Purdue University/Indiana Department of Transportation JHRP

  Purdue University, School of Civil Engineering
  West Lafayette, IN  United States  47907-1284
• Authors:
  • Krzeminski, R J
• Publication Date: 1976-8

Media Info

• Features: Figures; References; Tables;
• Pagination: 83 p.

Subject/Index Terms

• TRT Terms: Crash investigation; Crash rates; Drivers; High risk locations; Low volume roads; Perception; Reaction time; Rural highways; Skewed distributions; Speed distribution; Spot speed; Two lane highways
• Uncontrolled Terms: Driver reaction
• Old TRIS Terms: Driver perception
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00141550
• Record Type: Publication
• Report/Paper Numbers: JHRP-76-22 Final Rpt., File No: 8-5-18
• Files: TRIS, ATRI
• Created Date: Nov 3 1976 12:00AM