TRAFFIC UPDATES: Roads across the north island have been impacted by recent weather events. We’ll provide updates on our Journey Planner website as information becomes available. View our traffic map for road closures and delays(external link)

SCAM ALERTS: Report a phishing scam or learn about the latest phishing emails

CONTACT CENTRE WAIT TIMES: Our Contact Centre is currently experiencing significant wait times. View frequently asked questions

ONLINE TRANSACTIONS: We are experiencing issues with credit and debit card transactions on our website. We are working with the payment provider to resolve this as soon as we can. 

CONTACT CENTRE WAIT TIMES: Our Contact Centre is currently experiencing significant wait times. View frequently asked questions

REGO AND RUC LABEL ERROR: There was a postage error with labels purchased on the 15 August 2022. Find out more

ROAD USER CHARGES (RUC) DISCOUNT: Find out more about the temporary RUC reduction scheme

ONLINE SERVICES: We are currently experiencing issues with all our online services at the moment. We are working to resolve the services as soon as possible. We apologise for any inconvenience caused.

COVID-19 SERVICES UPDATE: Information on Waka Kotahi services, extensions and more

ONLINE SERVICES: We currently have an issue with receiving some payments and are working to resolve this issue as quickly as possible. We apologise for any inconvenience.

EASTER WEEKEND – PLAN AHEAD: Heading away for the long weekend? Check our holiday journeys tool(external link)

SCAM ALERTS: Refund email and Vehicle licence (rego) renewal phishing emails

CONTACT CENTRE PHONE LINES: Our Contact Centre phone lines are currently unavailable. View frequently asked questions

Background air quality is the level of contaminant across the airshed (a geographic area for air quality management) from all sources. This includes contributions from natural sources (for example volcanoes, forest fires and wind-blown dust) and from human-generated sources (such as industry, domestic heating and ‘remote’ roads).

Background air quality is used to assess the cumulative impact of a discharge to air. In the case of a roading project, the air pollution coming from the road being improved (the relative impact) needs to be added to the background concentration of air pollution (that is, background air quality excluding nearby roads) to allow the cumulative (or absolute) impact of the project to be calculated.

We have developed default background air quality values by census area unit. This information can be used as an input into an air pollution dispersion model, such as our Air Quality Screening Model to estimate the cumulative impact.

Air Quality Screening Model 

These default values are provided in the spreadsheets below:

Supporting information on the background methodology is available upon request from environment@nzta.govt.nz

In order to reduce uncertainty and comprehensively assess the air quality effects of a roading project, the default background air quality values may need to be supplemented with more site-specific information. Suitable data may be available from regional councils, Waka Kotahi or research organisations. However, projects with a high air quality risk, typically large projects in major urban centres, may require a dedicated monitoring campaign to determine background air quality.