Speed limit reductions to support lower SCRIM investigatory levels

This report details a framework for rationally arriving at economically justifiable operating speed reductions to compensate for the inability to achieve recommended levels of skid resistance on high-risk curves. The framework is based on vehicle speed-related procedures incorporated in the Transport Agency’s Economic evaluation manual. These procedures include travel time, vehicle operating costs, carbon dioxide emissions and crash severity. Relationships between the skid resistance level of the road surface and curve crash risk and expected service life of the road surface derived from previous New Zealand specific research are also employed. The framework was trialled on a 10 km section of state highway 58 with a 100 km/h speed limit. A decrease in operational speed of only 10 km/h was found to be sufficient to completely negate the increased curve crash risk that results when the skid resistance of the high crash risk curves is managed to a lower level of 0.4 ESC rather than the recommended investigatory level. The overall benefit of reducing the 100 km/h speed limit by 10 km/h amounted to an annual cost saving of about $1.5 million, with the reduction in speed change cycle costs making the largest contribution.

• Record URL:
  • http://www.nzta.govt.nz/resources/research/reports/636
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9781988512860
• Corporate Authors:

  New Zealand Transport Agency

  Private Bag 6995, Wellington 6141, New Zealand
  Wellington,    
• Authors:
  • CENEK, P
  • Henderson, R
• Publication Date: 2018-2

Media Info

• Pagination: 77p
• Serial:
  • Issue Number: 636

Subject/Index Terms

• TRT Terms: Benefit cost analysis; High risk locations; Highway curves; Skid resistance; Speed limits
• Uncontrolled Terms: Safe systems (roads)
• Geographic Terms: New Zealand
• ATRI Terms: Cost benefit analysis; Crash black spot; Crash costs; Curve; Skidding resistance; Speed limit
• ITRD Terms: 2872: Bend (road); 3031: Skid resistance
• Subject Areas: Finance; Highways; Law; I82: Accidents and Transport Infrastructure;

Filing Info

• Accession Number: 01663501
• Record Type: Publication
• Source Agency: ARRB
• ISBN: 9781988512860
• Files: ITRD, ATRI
• Created Date: Mar 22 2018 11:53AM