Certainty in pavement investments and performance

The New Zealand Supplement to the Austroads Pavement Design Guide draws attention to the need for a low risk of pavement failure occurring before the end of design life, and indicates pavement structures which result in reduced probability of failure and reduced maintenance costs. The process of pavement selection for new roads is closely tied to economic benefits, according to rules set by the funding agency, Land Transport New Zealand. The predicted time-stream of benefits and costs are discounted, using the Treasury mandated 10 per cent discount factor. Items accruing benefit and cost and evaluation guidelines are prescribed in the LTNZ Project Evaluation Manual. Unfortunately, the risk profiles of pavements and economic viability do not always relate so there is a conflict between the engineering and the economics objectives. The use of discounted cash flow combined with limited capital funding encourages least cost pavements because the downstream effects of maintenance have reduced impact through discounting. This paper explores the applicability of economic tools to an asset which must provide an acceptable level of safe service for a very long time, including appropriate risk profiling for different pavement structures and whole of life cycle investment data. (a)

  • Authors:
  • Publication Date: 2006-10


  • English

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Filing Info

  • Accession Number: 01054960
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Aug 6 2007 2:08PM