The following is a list of commonly used transport and air quality terms.
A printable version [PDF, 114 KB] of these terms and definitions is also available.
| A | Definition |
| AQ | Air quality |
| Air quality guidelines | Minimum requirements that outdoor air quality should meet in order to protect human health and ecosystems |
| Airshed | An area designated by a regional council or unitary authority for the purposes of managing air quality and gazetted by the Minister for the Environment |
| Ambient air | The air outside buildings and structures |
| Annual average daily traffic (AADT) |
The average daily vehicle count over a year in vehicles per day |
| B | Definition |
| Background air quality |
The level of a contaminant across the airshed from all sources. This includes contributions from natural sources (eg volcanoes, forest fires, wind-blown dust, etc) and from human-generated sources (eg industry, domestic heating and ‘remote’ roads). For roading projects, background air quality excludes the contribution of nearby roads |
| Board of Inquiry (BoI) | An independent body appointed to make a decision on a project of national significance |
| Busy local roads | Roads with an AADT greater than 20,000 vehicles per day |
| C | Definition |
| Carbon monoxide (CO) | A colourless and odourless gas resulting from the incomplete combustion of fuels, eg petrol |
| Census area unit (CAU) | An area classified by Statistics New Zealand for the purpose of the census. These areas are usually developed through the aggregation of smaller areas (meshblocks) to match suburbs and other local boundaries and areas |
| Certificate of fitness (CoF) | A mandatory check to establish whether a commercial motor vehicle is road worthy |
| Comprehensive air quality technical assessment |
A comprehensive assessment of the likely air quality impacts associated with the final design of the project. This assessment may also be referred to a Tier 3 assessment, and follows earlier less detailed or generic assessments |
| Concentration | The mass (weight) of a substance per unit volume, eg parts per million or milligrams per cubic metre |
| CAQMP | Construction air quality management plan |
| Continuous monitoring | Air quality monitoring undertaken by continuously collecting airborne gases or particles using a vacuum source in order to (usually) demonstrate compliance with an applicable regulation (eg a chemiluminescent NO2 analyser) |
| D | Definition |
| Design year | 10 to 20 years after the opening of a new or improved road |
| Designation | A form of 'spot zoning ' over a site or route, provided in a district plan, for a project or public work |
| Diffusion tube | A simple air quality monitoring device that absorbs pollutants over a period of exposure and is then analysed at a laboratory to determine pollution levels |
| Dust | Fine, dry powder consisting of tiny particles of earth or waste matter lying on the ground or on surfaces or carried in the air |
| E | Definition |
| Emission | The release of a substance to air (eg the discharge of a pollutant from vehicle exhaust) |
| ESR | Environmental and social responsibility |
| ESR screen |
The screen is a tool that has been developed by the Transport Agency to identify potential environmental and social risks (including air quality) associated with roading project options. The ESR screen is a high-level desktop assessment and is the first level of assessment in the development of a project. The ESR screen is equivalent to what is sometimes referred to as a Tier 1 assessment |
| EUD | Environment and urban design |
| Exceedance | A concentration of an air pollutant that exceeds a standard or criteria |
| Existing air quality | The air quality prior to implementation of the project being assessed. It is generally considered the sum of background air quality and the nearby road contribution |
| Exposure | The concentration of air pollution experienced by a person for a defined time period |
| Extinction coefficient (K) | A measure of the ability of light to pass through air (opacity). The higher the extinction coefficient (expressed as m-1) the less light that will pass through air |
| G | Definition |
| Government Policy Statement on Land Transport Funding (GPS) | Sets out the government’s priorities for expenditure from the National Land Transport Fund over the next 10 years |
| Guideline value | A concentration value against which air quality is assessed and managed |
| H | Definition |
| Highly sensitive receptor (HSR) | A location where people or surroundings may be particularly sensitive to the effects of air pollution, eg houses, hospitals, schools, childcare facilities, rest homes, and marae |
| %HV | Percentage of heavy duty vehicles (ie vehicles with a gross vehicle mass of over 3.5 tonnes) as part of the overall traffic volume |
| L | Definition |
| Land Transport Management Act 2003 (LTMA) | The planning and funding framework that central government funding into roading construction and maintenance and public transport |
| Link | A portion of a road between two intersections, junctions, interchanges or nodes. Its basic characteristics are length, vehicle speeds, travel times and the number of lanes |
| Local authority | A regional council, unitary authority, local council or territorial authority |
| M | Definition |
| Micrograms per cubic metre (µg/m3) | A unit of concentration |
| Milligrams per cubic metre (mg/m3) | A unit of concentration |
| Ministry for the Environment (MfE) | The agency responsible for advising central government on stewardship of the New Zealand environment |
| Ministry of Transport (MoT) | The government’s principal transport adviser, providing policy advice and support to Ministers |
| N | Definition |
| National environmental standards for air quality (NES) | Regulations made under the Resource Management Act 1991 which aim to set a guaranteed minimum level of health protection for all New Zealanders |
| Nearby roads | Any state highways within 100 metres and any busy local roads within 50 metres of the area or project under consideration |
| Nearest equivalent roadside monitoring site | A roadside monitoring site with comparable traffic flow and dispersion characteristics |
| Nitrogen dioxide (NO2) | An air pollutant produced from the combustion of fuels, eg diesel |
| Nitrogen oxides (NOX) | Collective term for the oxides of nitrogen, including NO2 |
| Notice of Requirement (NoR) | A notice given by a requiring authority (eg the Transport Agency) to a territorial authority (eg a city or district council) of the requirement for a designation for a public project or work. A proposed designation is referred to as a requirement for a designation |
| O | Definition |
| Opening year | The year in which the state highway improvement is completed and opened for public use |
| P | Definition |
|
Particulate matter (PM) (PM2.5) (PM10) |
An air pollutant produced from the combustion of fuels, eg diesel, road dust and other human and other human and naturally-generated sources. PM2.5 - particulate matter less than 2.5µm in diameter. PM10 - particulate matter less than 10µm in diameter |
| Passive monitoring | A method of air quality monitoring that does not use a mechanical method (eg a vacuum) for collection of an air sample. Diffusion tube monitoring is a common passive monitoring method |
| Preliminary air quality technical assessment |
An assessment of the likely air quality impacts associated with a project or project options. This assessment is undertaken to indicate whether an air quality guideline or standard is likely to be exceeded and to scope the requirements for Comprehensive air quality technical assessment. This assessment is equivalent to what is sometimes referred to as a Tier 2 assessment |
| R | Definition |
| Receptor | A location where any person (not just sensitive people) may be exposed to pollution from the road |
| Regional standards, targets and guidelines | Limits set to maintain and enhance a particular level of air quality in a region |
| Resource Management Act 1991 (RMA) | New Zealand's main piece of legislation that sets out how we should manage our environment |
| Reverse sensitivity | The legal vulnerability of an established activity (eg a road) to complaint from a new land use or activity (eg a new residential development) |
| Roads of national significance (RoNS) | Essential state highways identified by the Government as being linked to New Zealand’s economic prosperity |
| S | Definition |
| Significance criteria | Thresholds or triggers set to indicate whether it is likely that the project option under consideration will cause adverse air quality effects |
| T | Definition |
| Total suspended particulate (TSP) | A measure of likely dust nuisance that can arise from road construction activities |
| Tunnel |
The Transport Agency classifies a fully enclosed roadway greater than 80m in length as a tunnel |
| W | Definition |
| WHO | World Health Organisation, a United Nations agency that is concerned with public health |
| Warrant of fitness (WoF) | A mandatory check to establish whether a private motor vehicle is road worthy |
For further information contact environment@nzta.govt.nz.
