View all publications

Annex 7: Emissions from motor-vehicles in Auckland

As noted elsewhere in this report, domestic fires are the dominant source of PM10 air pollution for most urban areas in New Zealand but the Auckland region is the exception with motor-vehicles accounting for over 50% of PM10 emissions.  This raises the questions as to whether Auckland should be treated differently under the National Environmental Standard for Air Quality and how motor vehicle emissions should be included.
The key issues and options for addressing vehicle emissions in Auckland are:

  • motor vehicles are the single greatest contributor to urban air pollution in Auckland, being responsible for between 50 to 80% of all emissions;93
  • vehicle-related air pollution in Auckland causes approximately 244 premature deaths, 368,000 restricted activity days and $246 million in health costs per annum;94 and
  • emissions from vehicles need to reduce by 58% over 2005 levels to meet the PM10 standard in urban Auckland but achieving this target largely depends on central government intervention.

As seen in Figure 4 below, those initiatives designed to target diesel vehicles in particular are likely to yield the best improvements for Auckland’s future air quality.

Joint Air Quality Taskforce

A Joint Air Quality Taskforce with relevant central government agencies and the Auckland Regional Council was formed in 2006 and they produced a prioritised list of potential initiatives for immediate action.  Although considerable progress has been made in improving vehicle fuel quality and the adoption of emission standards, two principal areas that are still to be addressed are in-service testing (ie, testing of emissions when a vehicle is getting its warrant of fitness service) and increasing the uptake of cleaner technology.

Emissions screening of light-duty vehicles

Studies have shown that the total amount of emissions from the on-road vehicle fleet is dominated by a relatively small number of vehicles with very high emissions, referred to as “gross emitters”.95  In the 2003 Auckland campaign, the worst 10% of the vehicles were responsible for over 50% of the total hydrocarbon emissions.96

Remote sensing could be used to identify the likely gross emitters for compulsory emission testing. The current Auckland light fleet is estimated to have up to 90,000 gross emitters.

Emissions testing of heavy-duty diesel vehicles

Although it is difficult to justify the costs of compulsory emissions testing for all light-duty vehicles, this is not the case for heavy-duty diesel vehicles.

Heavy-duty diesel vehicles do approximately eight % of the total annual mileage97 in the region but are responsible for approximately 41% of the annual health costs.98  This health burden is likely to worsen because both truck and bus numbers and travel have been growing considerably faster than the light fleet metrics.99

Retrofits for heavy-duty vehicles

Emissions from heavy-duty vehicles vary significantly with emission-control technology. For example, a 20 year old bus (pre-Euro standard) emits nearly 10 times the amount of particulate matter of a five year old bus (Euro 3 standard).100

Replacing buses is expensive and each bus generally has a 20 year operating life.  However, overseas experience has shown that the older buses can be allowed to operate if cost-effectively retrofitted with diesel particle filters, which deliver a 90% reduction in particulate emissions.  These types of retrofits can be applied to buses built to Euro 2 or earlier emissions standards.

Given the timing of the introduction of New Zealand’s vehicle emissions standards it is highly likely that close to half the buses and trucks operating in Auckland (11,000 vehicles) were built either to Euro 2 or an earlier emission standard.

Assuming these older heavy vehicles would be candidates for retrofitting at least partial filters, with a one-off cost of $10,000 per unit, emissions from Auckland’s heavy-duty fleet could be reduced by 25% for approximately $110 million.101

Other motor-vehicle emissions reductions options

The historical “command and control” management approach does not incentivise more rapid shifts in behavior or technology uptake.  There may be opportunities to accelerate progress by adopting a “feebate” approach: eg, by applying differential registration and on-going licensing fees and revamping fringe benefit tax to encourage good practices and discourage bad ones. These schemes could be revenue-neutral, with the revenue from higher fees for more polluting, less desirable vehicles being used to offset the rebates for less polluting vehicles

Accelerated scrappage

Following the recent economic recession, many countries have offered “cash for clunkers” scrappage programmes, primarily to stimulate their faltering auto industries.
The following countries: US, Germany, Japan, Italy, Britain, Romania, Austria, the Netherlands, Spain and Serbia have announced subsidy schemes to provide an incentive for early retirement of older, less efficient vehicles.  The first three countries listed have introduced large incentives of US$4,000 to $5,000. Such schemes however have limited appeal here because of the absence of an automotive production or assembly industry.

Motor-vehicle options for the National Environmental Standard

All the options discussed above could be justified for the whole of NZ, in terms of health benefits, and may be required in areas out of the Auckland Region in future years.  However we have not assessed the overall costs and benefits of the options. Given the contribution of transport emissions to the Auckland region, the incentive for and feasibility of the options is greater there.  The following could be considered by the New Zealand Transport Agency:

  • a combination of emission screening with a limited number of tests on light-duty gross emitters (Auckland only);
  • emission testing of heavy-duty vehicles to improve maintenance and encourage retrofitting of diesel exhaust treatment (Auckland only); and/or
  • an incentive scheme to increase the rate of change to better engines with less emissions of pollutants and greater fuel efficiency (all NZ).

Figure 4: Relative contributions of various vehicles to PM10 emissions (mg per km)

Figure 4: Relative contributions of various vehicles to PM10 emissions (mg per km)

93 Note this refers to all emissions: ie, carbon monoxide, sulphur dioxide, nitrogen dioxide and ozone emissions as well PM10 emissions.

95 Fisher et al (2003).

100 The Euro standard is a set of standards based on tail-pipe emissions - the EU’s standards have been adopted by most countries other than the US.

101 This excludes the cost of any necessary repairs.