Every field measurement is imprecise and inaccurate to some degree, and therefore has associated uncertainty. The critical speed formula has been used for many years to estimate the speed of a vehicle that slips sideways and leaves yaw marks as it traverses a curved path. The inputs required for the formula are the radius of curvature of the path traversed by the vehicle's center of gravity and maximum lateral acceleration the vehicle can achieve before leaving yaw marks. The radius of curvature of the vehicle center of gravity path is generally determined by making an adjustment to the radius of curvature of a yaw mark deposited by the vehicle. This article looks at the consequences of uncertainty associated with measurements taken to determine the radius of curvature of critical speed yaw marks. The focus is on the sensitivity of the critical speed formula to uncertainty associated with field estimates of the radius. Recommendations are given regarding an optimum chord length for making radius measurements in the field.

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    3004 Charleton Court
    Waldorf, MD  United States  20602-2527
  • Authors:
    • Rose, N A
    • Hughes, C M
  • Publication Date: 2002


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 18-20
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00961691
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2003 12:00AM