Resources

In New Zealand, we use two models to estimate fuel use, which can be used to predict vehicle emissions. Researchers for this 2023–24 project studied how we could better link, integrate or align the models.

• The New Zealand Vehicle Operating Cost model estimates fuel use as a part of total vehicle operating costs, which can then be used to estimate vehicle emissions.
• The Vehicle Emission Prediction Model uses a comprehensive fleet model based on the New Zealand fleet profile and vehicle emission factors to predict vehicle emissions.

These models have different:

• ways of estimating fuel use
• use cases
• relevance to the current New Zealand fleet.

The researchers compared the models, consulted stakeholders, and proposed improvements and priorities. They ruled out combining the models but found opportunities to align some aspects for more consistent results, including aligning the models’:

• current estimates and future predictions of the New Zealand vehicle fleet
• vehicle speed modelling approaches
• estimates of road design’s effect on fuel use and emissions.

Their report also outlines the work’s scope for aligning aspects of the models. This includes guiding users on how to choose the best model for their needs and how to estimate fuel use and emissions.

Keywords: 

assessing model integration; New Zealand Vehicle Operating Cost model; Vehicle Emissions Prediction Model

Authors:

• Brook Hall, National Transport Research Organisation, Melbourne, Australia
• Daniel Ainalis, National Transport Research Organisation, Melbourne, Australia
• Robert Kochhan, National Transport Research Organisation, Melbourne, Australia
• Tyrone Toole, National Transport Research Organisation, Melbourne, Australia
• Jeremy van Dijk, National Transport Research Organisation, Melbourne, Australia
• Ian Greenwood, Greenwood Associates Infrastructure Consultants, Auckland, New Zealand