The information on this page relates to a range of tools and guidance available for technical experts to undertake resilience assessments on the transport network. 

Identify natural hazards and assess risk

The following tools and resources can be used to identify natural hazards and assess their risk. They can be used for sudden (acute) hazard events or slow onset (chronic) hazards events.

National Resilience Programme Business Case (NRPBC)

The NRPBC includes an evidence-base for future planning and investment decisions. It provides a national picture of vulnerability and exposure of New Zealand’s highway network to natural hazards.

National Resilience Programme Business Case

National Resilience Assessment Tool (NRAT) 

NRAT is an easily accessible digital tool that provides a nationally consistent overview of all the resilience disruption risks on the transport network. The tool makes it easier to assess, prioritise, monitor, and report on state highway damage/disruptions and network resilience more efficiently and effectively and allows funding to be targeted to the most critical sites.   

NRAT standardises how we capture data on both network damage and resilience risk. It collates: 

  • damage assessments  
  • geological risk assessments  
  • hydrological and other hazard risk assessments.

All data captured in this tool contributes to a ‘live’ geospatial database. NRAT is expected to be launched in late 2024.

Risk assessment (Low Frequency, High Impact) 

Earthquakes, tsunami, volcanic eruptions and storms are low frequency, high impact events that may impact the availability of the state highway network. Our State Highway Resilience maps provide an assessment of key natural hazards which are generally low frequency but can have high impact.  

These maps can be used to assess the exposure and level of risk along a corridor and can provide a comparison to other corridors across the country to indicate the focus and level of priority for investment. They also include an assessment of the extent and duration of the outage.  

These maps build on the national hazard exposure scan methodology, aligning with the expectation that a more thorough assessment of the problems is explored in the programme business case. A guide associated with each type of event (earthquake, storm, volcano, and tsunami) steps you through the process of a more thorough assessment at the regional/corridor level.  

The maps are open access. No user profile or login required.

State Highway Resilience maps(external link) 

Methodology to this tool [PDF, 1.2 MB]

Coastal effects assessment (chronic, slow onset hazard events) 

When planning new capital projects and maintenance and operations activities, coastal processes and relative sea level rise need to be considered for the impacts on infrastructure, as well as the effect of that infrastructure on the coastal environment. 

We have developed the Coastal effects assessment guideline for land transport infrastructure that outlines a coastal environment risk assessment approach to inform the planning, design, and management of state highway assets in coastal environments.

Coastal effects assessment guideline for transport infrastructure [PDF, 3.6 MB]

Future updates 

We are currently developing a Coastal hazards and land transport infrastructure guide, as a complementary guide to the Coastal effects assessment guideline for transport infrastructure.  

The assessment guideline will continue to serve as the primary tool for evaluating the overall impact of coastal processes on transport projects, ensuring that environmental, social, and economic factors are considered. The new hazards guide will provide the necessary depth and specificity to effectively manage the unique challenges posed by coastal hazards, offering practitioners the tools and knowledge needed to design and implement resilient transport solutions. By integrating the insights and recommendations from both guides, stakeholders will be better equipped to make informed decisions, enhance infrastructure resilience, and ensure the long-term sustainability of coastal transport systems.

Coastal processes

Considering Level of Service and community needs 

To understand what level of service the system, communities and networks need or expect, we use the following tools and resources. 

One Network Framework

Corridor management plans

Lifeline utilities - National Emergency Management Agency(external link)

Assessing historic disruption data 

To understand what disruptions have happened in the network in the past, we use the following tools and resources.

The Traffic Road Event Information System (TREIS)   

TREIS provides access to real-time data on events or incidents that affect traffic conditions across the national highway network. This information is only for significant events or incidents that may cause delays or require caution and verified by official sources. 

Examples include road works, a crash, or weather-related events such as ice or snow.

Traffic and Travel APIs

Detour viability 

To make sure people can complete their journeys, we need plans in place for when usual routes become unavailable. 

Detour Routes Tool 

We have created interactive detour maps that can be accessed by anyone. With this tool users can identify alternate routes, comparative distance and travel times, which vehicle types each route is suitable for, and other key information. 

Detours within the tool are pre-agreed by local authorities and NZTA Waka Kotahi. Using detour routes can also help assess resilience risks in specific areas. 

Detour Routes Tool(external link)  

Assessing economic impact 

Measuring the economics of resilient infrastructure tool (MERIT) 

Depending on the type of resilience risk, the standard economic appraisal process may not fully represent the economic benefit of investing in resilience. To enable a broader assessment of the economic impact, we use MERIT.  

MERIT a dynamic, multi-regional and sectoral economic model that assesses the economic impact of a potential or actual network outage on our network.  

MERIT contains all the core features of a computable general equilibrium (CGE) model. At NZTA we use MERIT to assess the economic impact of our proposed programmes.   

Further information on MERIT: 

merit.org.nz(external link) 

Summary document of MERIT  [PDF, 741 KB]

Technical report on dynamic economic modelling  [PDF, 1.7 MB]

Brief video introducing the MERIT tool  [MP4, 27 MB]

Below are case studies of using the MERIT tool in real major network outages: 

Economic impact of the SH3 Manawatu Gorge 2011-12 outage: MERIT pilot [PDF, 403 KB]

Economic impact of the SH4 outage – June 2015  [PDF, 719 KB]