Road Seal Extension Policy


1. Purpose

This policy details the approach taken by Timaru District Council to prioritising and funding road seal extension projects within the District.

2. Background

The Timaru District Council supports road seal extensions in the District that meet policy criteria, subject to available funding.
The principles on which this policy is based are:

  1. Appropriate Criteria:
    • The policy must use relevant factors that can be objectively assessed.
  2. Fairness:
    • The policy established must be perceived by most people as fair and consistent.
  3. Effective:
    • Evidence based and logical in application;
    • Consistent over time.
  4. Transparency:
    • The prioritisation system uses simple mechanisms easily understood by all.
  5. Community Benefit:
    • Recognition that communities are interdependent and the cost of seal extensions cannot wholly be placed on the specific user.
  6. Uniform Availability: 
    • That funding is provided by all District communities, and projects must be considered in a District wide manner for entire District community benefit.
  7. Funding Efficiency:
    • Funding from sources external to Council will be maximised (e.g. government funding assistance, contributions).

3. Key Definitions

Contribution: Funding provided by an external person/ratepayer, organisation or trust.

Funding Assistance: Previously referred to as “Subsidy” or “Financial Assistance”. This shall mean the government funding assistance from National Land Transport Programme allocated by New Zealand Transport Agency (NZTA) for activities.

Road: This is the designated Council road and has the meaning assigned to it as defined in the Local Government Act 1974, section 315, and Land Transport Act 1998, part 1, section 2.

Seal: The surfacing known in New Zealand as a chipseal and consist of stone chip embedded in a 1-2mm think film of bituminous (or synthetic) binder, to provide a thin waterproofing layer as the top surface of a pavement.

Seal extension: Increasing the sealed carriageway pavement length.

Unless specifically defined in this policy, all words and expressions shall have the meaning as defined in the Local Government Act 1974 and 2002, the Land Transport Act 1998, and any Acts passed in amendment or substitution thereof.

4. Policy

  1. Council will fund seal extensions to a budget determined during the Long Term/Annual Plan process.
  2. Council will seek to maximise funding assistance from NZTA and contributions for seal extensions.
  3. The Timaru District Council Land Transport Unit will maintain prioritisation procedures to guide assessment of prioritisation of seal extension projects. These procedures will be utilised to rank unsealed roads as/when funding is available. At minimum the procedures will incorporate an assessment against the following criteria:
    • Number of traffic movements
    • Number of dwellings per kilometre
    • Lifeline priority assessment*
    • Roughness index average**
    • Historic maintenance costs***
    • Crashes****
    • Heavy vehicle usage*****
    • Extent of private funding contribution.
    • Regional and local value of the project e.g. improving access to regionally significant reserves/parks, improving access to development/growth areas identified in the District Plan, supports economic growth/tourism in the District.
  4. The following criteria will be assigned greater weight in the assessment, due to the higher relative impact of these criteria on maintenance frequency and cost: Lifeline priority assessment, heavy vehicle usage, extent of private funding contribution, dwellings per kilometre.  Projects of relative regional value will also be weighted more greatly.
  5. Council may undertake road seal extensions that are not eligible for funding assistance or contributions (100% Council funded) in special circumstances subject to available budgets and approval by the Infrastructure Committee.
  6. Council will monitor all unsealed roads and any changes will be documented in the road asset management software.
  7. Ratepayers or residents wishing to seal the road adjacent to their property at their own cost will require Council approval before proceeding. All sealing work must meet Council standards and adjoin an existing seal.

*Lifeline priority assessment determines the criticality of a road in supporting community connections to essential services. It is used by Council’s Land Transport Unit to assist with prioritisation during emergency events and is a proxy for contribution to community resilience.

**Roughness index average is calculated using average eIRI over the previous two years (best data available at time of assessment).

***Historic maintenance costs are calculated using the average maintenance cost over the previous five years (best data available at time of assessment).

****Crashes refers to the documented crashes that have occurred on the unsealed road in the previous five years. If more than one crash has occurred, the highest crash severity recorded will be used to determine scoring.

*****Heavy vehicle usage is movements of a vehicle with a gross vehicle mass of greater than 3.5 tonne vehicle/axis.

Adopted by the Infrastructure Committee – March 2024

Last updated: 04 Apr 2024