Marlborough District Council Roading Assets - Activity Management Plan 2015 - 2018 SECTION 1 EXECUTIVE SUMMARY 1.6.2 Unsealed Roads Pavement 1.6.2.1 Physical Description The total roading network administered by the Marlborough District Council (Council) consists of 1526km of road of which 886km is sealed and 640km is unsealed. This section of the AMP covers the management of the 644km of unsealed roads pavement. The 640km includes the 54km of D’Urville Island road which is physically separated from the balance of the roading network by French Pass. As a consequence of the separation by sea, portions of the French Pass jetties are considered part of the roading asset. The roads have been separated into five categories based on their function (ref to clause 2.2). The length of unsealed network by category is as follows: Hierarchy Description Type* Unsealed Length % of Unsealed km Network Primary Arterials R2 0.0 0% Secondary Arterials R3 0.0 0% Collector Roads R4 78 12% Local Roads R5 461 72% Local B Roads R6 101 16% Total 644 Table 6.2.1a: Unsealed Length by Hierarchy * R1 Roads are State Highways, ref NZTA AMP * R5 road length includes all D’Urville Island roads The unsealed R4 roads include the Northbank and Awatere Valley Roads. The R5 roads describe all the main feeder roads to French Pass, the Kenepuru Heads region, the Port Underwood routes, the Wairau Plains and the Flaxbourne region. The R6 roads are predominantly the spur feeder roads onto the R5 routes. The road hierarchy is used in determining the standards of construction to be used and prioritising future road improvements. A full list of roads and their designations is shown in Appendix A. At the time of preparation of this plan the new NZTA ‘One Network’ road classification system is being set up for the Marlborough Network. The One Network system will be a uniform classification system to be used across all TLA and NZTA networks (local roads and state highways). The system will set levels of service for each road classification thereby setting a common ‘standard’ for roads within each classification across the country. The effect on the Marlborough unsealed network is not known at the time of preparing this plan but is unlikely to significantly alter the current levels of service. The unsealed road network asset can be divided into two elemental components: pavements and surfacings. Pavements are the structural element of the road and are generally compacted granular layers on the insitu ground or subgrade. The surfacing on an unsealed road is the wearing course of fine, loose metal. As these components have different levels of service and life cycles they need to be considered separately when considering the management of the asset. 1.6.2.2 Age and Current Condition The pavement for a modern unsealed road is designed in a similar way to that for a sealed road. However the construction of most unsealed roads within Marlborough have tended to be as a progressive upgrade from the original earth bridal track by way of progressively adding basecourse metal, hence there is no formal design nor any reliable age data. The RAMM history data for unsealed roads is incomplete however specific pavement depth investigations have been recorded against the more significant unsealed routes. Most of the unsealed roads do have a pavement depth which is adequate for the need and return a reasonable service life. As with sealed road pavements, any significant increase in heavy vehicle movements or HMV usage during very wet weather periods leads to a rapid deterioration of the pavement. 30 September 2014 Page 52 of Section 1