Analysing safety and geometric elements

Many of New Zealand state highways in a rural environment have sections of sub-standard geometric curves and therefore often become deficient in skid resistance. Furthermore, the severity of run-off road loss of control crashes is often increased due to having inadequate clear zones. Yet, given the difficult topographic conditions, it is often uneconomical to implement the AASHTO standards for clear zones on the highway networks. In the Northland state highway region, there is concern about the level of safety operating on complex horizontal geometric curves. The cost of complete rectification of geometrics is often prohibitive. The loss of skid resistance and cost of rectification is also very high. Given the above constraints, a balance is required to produce an optimal incremental improvement meeting the demand for adequate safety. As part of a University of Auckland research project, an analysis was undertaken at two chosen case study sections analysing crash risk and the various combined geometric elements. The data for analysis is taken from the RAMM and CAS databases. The paper discusses a methodology that combines horizontal geometry and friction demand with the existing high speed data condition surveys to examine correlation between crash locations and road condition.


  • English

Media Info

  • Pagination: 11p
  • Monograph Title: Moving towards prosperity: IPENZ Transportation Group 2011 Conference, Auckland, 27-30 March 2011

Subject/Index Terms

Filing Info

  • Accession Number: 01339132
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ARRB, ATRI
  • Created Date: May 9 2011 9:53AM