Transport-related air pollution impacts human health, with effects ranging from respiratory irritation, wheezing and coughing, through to more serious respiratory and cardiac conditions leading to increased hospitalisations and premature death. Air emissions play a role in shortening the lives of over approximately 3,300 New Zealanders each year and cause social costs of $15.6 billion per year (Health and air pollution in New Zealand 2016).

Air pollution can also reduce visibility and cause brown haze. Construction of land transport infrastructure can negatively affect air quality by creating dust and sometimes odours.

Of most concern to health are fine particles and oxides of nitrogen from vehicle tailpipes, and fine particles from brakes and tyres of vehicles. For more information about the causes and effects of air pollution, read our air pollution frequently asked questions.

Frequently asked questions about air pollution

We are committed to reducing the environmental and health effects of transport-related air pollution caused by our infrastructure by:

  • assessing and mitigating the air quality impacts of our land transport infrastructure during planning of new projects
  • mitigating negative effects on air quality where we can, for example installing ventilation in tunnels
  • managing dust and odour at our construction sites to ensure we don’t pollute the air or waterways
  • monitoring air quality near our land transport infrastructure, which allows us to monitor trends and impacts of interventions over time, and helps inform modelling, research and air quality policy.

We are also working to reduce the air pollution caused by vehicles that travel on our roads by:

  • investing in more sustainable modes of transport, which include walking, cycling and public transport
  • supporting the uptake of lower-emission vehicles such as electric vehicles
  • administering rules and regulations related to vehicle emission standards.

Walking, cycling and public transport
Electric vehicles
Environmental standards for vehicles

Air pollution and greenhouse gas emissions

Vehicles are one of the largest sources of greenhouse gas emissions in New Zealand. Reducing all emissions will benefit not only human health but also the health of the planet.

Climate change mitigation

Our policy

Our policy on air quality can be found in:






Waka Kotahi research reports

Research stocktakes


Air quality reports

Tunnel reports

Remote sensing reports

External standards and guidance

Further information

For further information contact