Vehicle emission reduction technologies are continually improving. In theory, as new vehicles replace old ones in the fleet and as fuel quality improves, the amount of pollutants discharged on a per vehicle basis should (on average) be reducing. However, it is unclear how much influence new technology and improved fuel is actually having on the 'real-world' emissions from the light duty vehicle fleet as a whole.
This project used remote sensing to measure real-world vehicle emissions in Auckland in 2009 and then compared the results with measurements taken at the same sites in comparable campaigns undertaken in 2003 and 2005. The main objective of the project was to address the question: Are the harmful emissions from New Zealand's light duty fleet improving under the current 'business as usual' scenario?
Emissions measurements (carbon monoxide, nitric oxide, hydrocarbons and uvSmoke as an indicator of fine particulate matter) were stored together with vehicle information (such as fuel type, age, odometer reading and emission standard) enabling the effect of each parameter and any trends to be assessed.
The results confirmed that New Zealand's light fleet emissions are indeed generally improving with current trends. However, three trends of concern were identified and require on-going monitoring.
Keywords: emission standards, emission trends, remote sensing, vehicle emissions