Extract:

Appendix 1. Traffic, Externality and Macroeconomic Modelling 

This Appendix provides technical detail to support The Cost of Congestion White Paper. It does not provide any additional results or findings, but instead sets out the foundation for micro and macroeconomic modelling, supporting the transparency of analysis. The Appendix is primarily intended for traffic modellers, policy advisors, and other analysts interested in detailed methodology information. Information is split into three sections:

1. Transport Modelling:  Assessing congestion impacts required forecasting potential user responses to changes in the Auckland transport network at a regional level. The Auckland Forecasting Centre (AFC) conducted this input into our analysis using its Macro Strategic Model (MSM).
2. Externality Modelling:  Building on MSM outputs, as well as published appraisal guidance, to estimate a total monetised cost of congestion. Externality modelling reflects the societal costs and benefits generated from differing transport outcomes. These costs and benefits largely reflect nonmarket impacts, and the trade-offs associated with them.  
3. Macroeconomics Analysis:  Elucidation of the Computable General Equilibrium (CGE) model that underpins macroeconomic benefits, quantified within the Report. It focusses on underlying principles, source data, and key features. The section concludes with a short discussion of New Zealand Treasury guidance, and implications for the appropriate treatment of CGE results.

We note that a full explanation of underlying models, for example the MSM process, is not practical to canvass within this appendix. Weblinks and references are provided throughout each section to indicate where such information can be found. 

Auckland Transport | Arup, EY

January 2025, 2024

See also

Auckland’s cost of congestion