Development of an Alignment Transition Index for Highway Alignment Consistency Assessment

Alignment design consistency is an important highway geometric feature affecting traffic safety. Generally speaking, the smaller the difference of alignment features between successive road segments, the better the alignment consistency is and the better the highway safety is. On the basis of research works on safety effect of alignment features in terms of curvature change rate and grade, the integrated alignment index for each road segment has been developed which is in consists of alignment elements, including curve radius and grade. Then the alignment transition index has been defined as the difference of the integrated alignment index between successive road segments. It’s easy to understand the alignment index can express the alignment feature and the alignment transition index can express the difference of the alignment feature between successive road segments. In this way, the alignment transition index supposes to have strong relation with alignment consistency. A pilot study was implemented to develop the relation between the alignment transition index and alignment consistency. The relation between the alignment transition index and the speed difference between successive segments at tunnel entrance and exit has been studied based on the collection of large number of speed and alignment data. The statistical analysis shows the speed difference between successive segments has good correlation with alignment transition index. And then the relation between the alignment transition index and the speed difference between successive segments has been modeled. On this basis, the alignment consistency assessment criteria based on alignment transition index has been developed.

  • Corporate Authors:

    Polytechnic University of Valencia

    Department of Transportation, Camino de Vera
    Valencia,   Spain  46022
  • Authors:
    • Wang, Yan
    • Guo, Zhong-yin
    • Li, Lin
    • Li, Ai-min
  • Conference:
  • Publication Date: 2010

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 11p
  • Monograph Title: 4th International Symposium on Highway Geometric Design, June 2-5, 2010, Valencia, Spain

Subject/Index Terms

Filing Info

  • Accession Number: 01338151
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 25 2011 2:16PM