Innovative and Cost-Effective Approach to Develop Robust Short-Term and Long-Term Drainage Programmes

On the national highway roads, there is a relatively-new contract model, established by the New Zealand Transport Agency, that is based on achieving the levels of service at least whole-of-life cost. The mechanism for this is through incentivising preventative maintenance work, primarily drainage, to defer the need to undertake pavement and surfacing renewals. The drainage activities are split into two types: - Formed assets, which includes high lip, side slopes and side drains, and - Hard assets, which includes culverts, manholes, catch pits, subsoils and scour protection. The basis for the works programmes is segmentation of the road network into 100m-long drainage assessment lengths (DAL) based on the drainage-related pavement and surfacing risk (high, moderate and low). The DALs are derived from: - Annual rainfall, - Subgrade geology, - Carriageway runoff (crossfall and longitudinal fall), - Verge runoff (road and shoulder level relative to the surrounding terrain). Once the DALs have been determined, the authors then establish the high, moderate and low-risk subnetworks. These drainage subnetworks are then the basis for the development of the short and long-term works programmes for formed and hard assets, as follows. The long-term (10 and 30 Year) Forward Works Programmes (FWP) for formed assets are based on undertaking a condition rating every 3 years. The prioritisation is then determined within each condition ‘bucket’ based on sites with drainage-related pavement and surfacing defects, and the risk rating of the drainage sub-network. Every three years, the authors repeat the condition rating and note which DALs have changed condition, including the sites that we have treated. This methodology ensures that the longer-term programme becomes more and more robust. For the shorter-term programme, we use ‘condition’ as the primary driver and then the authors rank the treatment lengths for each ‘condition bucket’, based on: - Pavement and surfacing risk related to drainage, - Road Classification (route importance and criticality), - Drainage Sub-network (high, moderate or low), - Pavement and Resurfacing Renewal Forward Works Programmes (higher ranking for sites with pavement or surfacing renewals in Years 2 to 6, based on the opportunity to defer the renewal). For hard assets, both the longer-term and shorter-term programmes are based on: - Asset remaining life, -Flooding risk, - Pavement and surfacing risk, - Personal risk (volume of traffic). This paper describes the innovative methodologies to develop these works programmes.

• Record URL:
  https://pre-proceedings-abudhabi2019.piarc.org/ressources/files/4/IP0493-Hunt-E-Full.pdf
• Supplemental Notes:
  • Abstract reprinted with permission of the World Road Association – PIARC.
• Corporate Authors:

  World Road Association (PIARC)

  La Grande Arche, Paroi Nord, Niveau 5
  F-92055 La Defense Cedex,   France 
• Authors:
  • Hunt, S
• Conference:
  • 26th World Road Congress
  • Location: Abu Dhabi , United Arab Emirates
  • Date: 2019-10-6 to 2019-10-10
• Publication Date: 2019

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: Proceedings of the 26th World Road Congress - Abu Dhabi - 2019: Connecting Cultures - Enabling Economies

Subject/Index Terms

• TRT Terms: Concrete forms; Cost effectiveness; Culverts; Drainage; Highway maintenance; Innovation; Level of service; Life cycle costing; Runoff; Surfacing
• Identifier Terms: New Zealand Transport Agency
• Geographic Terms: New Zealand
• Subject Areas: Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 01756607
• Record Type: Publication
• Files: TRIS
• Created Date: Oct 29 2020 9:35AM