Marlborough District Council Roading Assets - Activity Management Plan 2015 - 2018 SECTION 1 EXECUTIVE SUMMARY The rehabilitation of those unsealed lengths which have been damaged or which are likely to suffer damage due to projected increases in loadings is addressed by the application of maintenance metal under the renewal process. Maintenance metal is specifically manufactured to allow a compacted pavement layer to be constructed on the existing pavement. Where the local pavement conditions allow and where specifically weak sub-structures exist, in situ stabilisation of the existing pavement using lime or cement is undertaken to strengthen the unsealed pavement. The condition of the unsealed roads is monitored against the maintenance contract standards / Operational Performance Measures (OPMs). The OPMs compliance audits are undertaken on a two monthly basis on a randomly selected 5% sample of the network. The audits include a visual inspection and a roughness survey using an ARRB Roughometer III Roughness Meter. Audit results are reported in the contractor’s monthly report. The condition of unsealed roads can change rapidly subject to weather and traffic conditions. Audits are undertaken two monthly to reflect seasonal changes and give a better assessment of whether the contractor’s maintenance regimes are achieving the desired results. The audits rate the condition of the unsealed network for compliance with the Levels of Service defined in Section 6.2.3. 1.6.2.3 Level of Service Council has optimised levels of service within existing budget allocations however it is becoming increasingly difficult to provide acceptable levels of service particularly on those parts of the network where increasing traffic volumes are occurring. Viticulture development is adding to the traffic growth but seemingly user expectations are also increasing with motorists continually seeking higher levels of service. Section 3 of this AMP discusses customer Levels of Service. The detailed list of technical performance measures are listed in the Marlborough Roads Safety Management System Manual (refer SMS 70, ‘Unsealed Pavement Mtce’). In order to meet the appropriate level of service, Operational Performance Measures (OPMs) are set in the network maintenance contract specifications. The maintenance contracts therefore define the OPMs and contribute to the overall objectives. The OPM’s in the current maintenance contract, at the time of preparing this AMP, are aligned to meet the current level of service. Any changes to these levels of service will need to be either a variation to existing contract or be incorporated into the next contracts when they are prepared. Ideally it would be desirable to seal all Marlborough District Council gravelled roads however careful analysis of the benefits would be required especially on roads with less than 200 vehicles per day. The likely cost to seal 660km of gravelled road would be in the vicinity of $100M. Clearly this is an unachievable target in the short to medium term. The monitoring and measurement of roughness is considered to be a cheap and reliable indicator of unsealed pavement performance. Where roughness is recorded in excess of a predetermined level, intervention by grading or by the addition of pavement metal depth may binie dcte.ad The ARRB Roughometer III Roughness Meter has been used successfully since 2012 to determine the relative roughness of unsealed roads and compliance with desired levels of service. It is also a useful tool in determining the validity, or otherwise, of complaints from the public about unsealed road roughness. The current specification calling for an average roughness not to exceed 200 NAASRA counts over any 500 metre continuous length appears satisfactory but more investigation is required to ensure this level aligns with public expectation of the condition of unsealed roads. Some further roughness monitoring and the establishment of performance baseline levels of roughness limits is recommended in this AMP. 1.6.2.4 Demand / Growth The predicted growth and future demand discussed in Section 4 of this AMP have been further assessed as to their effect on the unsealed road asset. The unsealed network reduces in length by approximately 0.7% per year due to effect of seal extension works. No new unsealed roads are added to network therefore the total length is reduced by around 5 km per year. There has been a consistent increase in heavy vehicle usage and truck size on the unsealed network as the regional forest, aquaculture, viticulture and farming industries come into full production and employ the most cost beneficial methods to move their produce. 30 September 2014 Page 53 of Section 1