A Three-Dimensional Method for Safety Evaluation of Highway Geometric Design

Constrained by the available two-dimensional design tools in market, the two-stage method has been traditionally adopted by road engineers for its great convenience. Parameters of horizontal and vertical alignments are considered and determined discretionally, which potentially de-emphasizes the three-dimensional nature of spatial curves. The objective of this research is to focus on the three-dimensional attributes of highway alignments and further explores a safety evaluation method to determine the interrelation between crash rate and spatial curve properties. At first, highway alignment combinations were categorized into 6 classifications, with their respective spatial expressions in mathematical form. Curvature and torsion of spatial curve were algebraically manipulated, and the correlation between geometric design variables and crash rate was finally determined. A few cases encompassing the data of the geometric design and crashes facts were utilized for verification. The results showed that there is a significant positive correlation between curvature/torsion variance and crashes per million vehicles-kilometers, as a slight difference between curvature and torsion could also be spotted. And curvature distribution is found more closely related to crash frequency than torsion spatial variation.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFB10 Standing Committee on Geometric Design.
• Authors:
  • Wang, Jiahao
  • Wang, Lu
  • Zhou, Hao
  • Jing, Wenbing
  • Cheng, Jianchuan
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 18p

Subject/Index Terms

• TRT Terms: Crash rates; Highway curves; Highway design; Highway safety; Mathematical methods; Safety management; Spatial analysis
• Subject Areas: Design; Highways; Safety and Human Factors;

Filing Info

• Accession Number: 01657025
• Record Type: Publication
• Report/Paper Numbers: 18-01849
• Files: TRIS, TRB, ATRI
• Created Date: Jan 23 2018 9:28AM