What is PEET?

The Project Emissions Estimation Tool (PEET) is a greenhouse gas (GHG) emissions estimation tool that has been developed for use in the early stages of a land transport infrastructure project. PEET uses standard design examples and industry research to enable calculation of a high level estimation of the GHG emissions through the life cycle of a project, including:

  • construction 
  • operations and maintenance 
  • vehicle use (by calculating enabled and/or avoided emissions through applying the Vehicle Emission Prediction Model (VEPM)).

PEET includes elements for state highways, local roads and rail and has been developed in collaboration with Waka Kotahi, Auckland Transport and KiwiRail.

For calculating emissions from transport model outputs, use the Traffic Model Emissions Tool, which applies emission rates from VEPM to the output data from the traffic model.

Vehicle Emission Prediction Model (VEPM)
Traffic Model Emissions Tool

Information from PEET can be used to inform decisions on a project or programme business case and to estimate emissions for different design options. 

Using PEET 

Current and past versions of PEET

A summary of the current and previous versions of PEET are provided below.

Version Notes
PEET v4.0

PEET v4.0 spreadsheet (password protected) and user guide [ZIP, 7.2 MB]

Released October 2023. This version contains the following changes from v3.0:

PEET v3.0

Released in December 2022 (beta version).  This version contained the following changes from v2.6:

  • updates to construction first order to provide baselines from New Zealand and Australian projects only
  • inclusion of local road and rail elements to the construction analysis
  • inclusion of emission reduction analysis for construction second order estimates
  • VEPM table updated to latest version VEPM6.3.
PEET v2.6   Released in May 2022 (beta version).

We are continuing to improve this tool. You can send us any feedback via environment@nzta.govt.nz.


Waka Kotahi does not represent or endorse the information, content, presentation or accuracy of this PEET tool and its contents.

Read the full disclaimer

PEET has not been developed to provide a detailed emissions analysis of specific project elements; the tool only considers the most significant emission sources in a project life cycle. PEET is not a replacement for detailed transport modelling or a detailed emissions assessment for infrastructure design. The limitations, key assumptions and sources of uncertainty associated with any estimate made using PEET should be clearly stated in any documentation or presentation of results. Results from PEET are not to be relied on for publication of emission reductions from a project and it does not replace the IS Materials Calculator for those projects pursuing ISC sustainability rating and certification. 

Sustainability rating scheme

Privacy statement

When you email us to request the password for PEET, we collect your name and email address. These details will be added to a mailing list that is only used to let you know about PEET updates, for example when we make a change to the tool, or when we conduct surveys regarding improving the tool. You can request access to and correction of that information at any time by emailing environment@nzta.govt.nz.

If you do not wish to receive emails about the PEET tool, please tell us; and remember to check this web page regularly for updates and changes to the PEET tool. 

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