New Zealand Project: Designer Perspective

Road safety audits of the design have been conducted during the tender phase (Stage 2 audit), at the commencement of the contract phase (Stage 2.5 audit), and on completion of the detailed design (Stage 3 audit). End-of-construction (Stage 4) audits have yet to be carried out. The Stage 2 audits were conducted on each of three tenderer’s concept designs and the Principal’s specimen design. These audits addressed the relative safety and operational benefits as well as the deficiencies of each design. However the design subjected to this audit was that developed within the initial 8 weeks of an 18 week tender period, and the finally submitted tender design had undergone significant further development. The tender design included an assessment of geometric non-conformances in the design together with the designer’s proposed actions to address these in the contract phase. However the Principal provided no direction in this matter, and the Principal’s decisions on safety issues identified in the Stage 2 audit were limited to one key issue involving sight distance to a lane-drop diverge. Consequently the designer elected to subject the concept design to the Stage 2.5 audit almost immediately following the award of the contract. Even at the early stages of the detailed design there is a pressing need to progressively “lock in” geometric elements in order for the design of critical structural and other civil elements to proceed. The Stage 2.5 audit was conducted with the audit team’s acceptance of the tendered configuration of the new and relocated links, and addressed the geometric layout in considerable detail, with a particular focus on the exit/diverge and entrance /merge arrangements, sight distance along carriageways and uniformity of shoulders. Subsequent design development was re-submitted to the audit team after a short interval for review of key elements, and this review was documented in an audit report Addendum. The Stage 2.5 audit process proved to be highly successful in providing early focus and direction for the subsequent detailed design work. Stage 3 audits have been conducted on four detailed design packages and have followed a conventional audit process with designer’s response and Principal’s decision documents being prepared after each audit report.


  • English

Media Info

  • Media Type: Print
  • Features: CD-ROM;
  • Pagination: 2p
  • Monograph Title: ITE 2005 Annual Meeting and Exhibit Compendium of Technical Papers

Subject/Index Terms

Filing Info

  • Accession Number: 01006822
  • Record Type: Publication
  • ISBN: 1933452080
  • Files: TRIS
  • Created Date: Oct 25 2005 10:16AM