Managing maintenance on state highways

There are minimum criteria for condition and availability when maintaining and operating our network. We contract this to consultants and contractors in each of our 25 network management areas around the country.

The different types of contract we use to do this play an important part in ensuring those levels of service are met. We also closely monitor the cost of this work to determine the point at which more than maintenance is required to meet road users' expectations.

Our contract framework

We use five contract types to procure maintenance and operations:

• Alliances– special arrangements in which groups of organisations combine in partnership and work together. For example, an alliance is currently contracted to operate and maintain the Auckland motorway network in a long-term agreement that began in 2008.
• Performance-specified contracts, which are awarded for 10 years to single suppliers who are responsible for providing all services. There are five such contracts operating in New Zealand, including one for maintaining the Auckland Harbour Bridge. Most resurfacing work is also done under performance-specified contracts.
• Hybrid contracts, which are awarded for five years and involve consultants and contractors working in a partnering arrangement to deliver services.
• Traditional contracts, which are awarded for varying terms and involve consultants managing suppliers who deliver physical works on the highway network, in a similar way to traditional road engineering construction contracts. Most pavement strengthening works and bridge repairs are managed through this type of contract.
• Network outcomes contracts, which are a new approach to our maintenance and operations to ensure efficiency and effectiveness through better asset management and service delivery. These contracts are awarded to primary suppliers and are performance-based. This is a new contract model and the contracts are being phased in over the next two-and-a-half years.

Specifying maintenance requirements

All our contracts for state highway maintenance work specify levels of service that must be achieved. These are expressed as either:

• response times to events, such as flooding or
• standards/intervention levels, such as how easy it is to read or see signs and paint lines, the height of the grass and the amount of roadside litter.

We also manage New Zealand's roading standards and guidelines(external link) on behalf of all 74 road-controlling authorities.

Monitoring maintenance costs and asset data

Through our maintenance contracts we collect information on the costs of maintenance per year and per kilometre. This is stored in the roading assessment and maintenance management RAMM (road assessment and maintenance management) database.(external link)

The types of data held in RAMM include:

• condition data – how rough the road is, its skid resistance under wet conditions, the strength of the pavement and defects such as cracks, rutting and flushing
• a register of the assets on the state highways such as road structure (surfacing and pavement layers), signs, railings, retaining walls and drains
• records of routine maintenance activities
• a plan of work for future maintenance of the roads.

Working with our consultants and contractors, we use this RAMM information to identify the sections of the state highway network where we may have to do renewal and strengthening work. If it costs less to replace or strengthen the road than to continue maintaining it, the renewal work becomes a high priority.

Local authorities also use RAMM to manage the inventory and maintenance of their networks. This has the advantage that a consistent national comparison and compilation of asset data and condition is possible.

Identifying maintenance locations

To describe locations along the highway for maintenance work, we use a distance-based reference station system. All highways have a nominated 'zero' point (for example, Cape Rēinga is the zero point for State Highway 1 in the North Island) and any point can be described using intermediary points called 'reference stations'.

For example, if you're travelling south on State Highway 1in the North Island, you first meet Lake Taupōon The Esplanade at 01N-695-8500 – that is, 8,500 metres past Reference Station 695, which is roughly 695 kilometres from the start point at Cape Rēinga.

Although we’re increasingly using spatial locations and GPS equipment in some areas, the distance-based reference station system is still a cost-effective, efficient and useful option.

Find out more about our locations system, the signs used and what they mean

Related links

• State highway maintenance boundaries
• State highway maintenance wall planner
• Roading standards and guidelines
• Large Maintenance Contracts Programme
• NOC variation clarification