COVID-19 SERVICES UPDATE: Information for all alert levels, Waka Kotahi services and more

SCAM ALERTS: Refund email and Vehicle licence (rego) renewal phishing emails

ONLINE SERVICES: We currently have an issue with receiving some payments and are working to resolve this issue as quickly as possible. We apologise for any inconvenience.

EASTER WEEKEND – PLAN AHEAD: Heading away for the long weekend? Check our holiday journeys tool(external link)

Road traffic noise calculator

This calculator predicts road-traffic noise in situations without complex topography. Each tab contains different input fields required for the calculation. A PDF of the inputs and result can be generated on the ‘Export’ tab. The PDF file will also contain a link to reopen the calculation at a later date. Help text is available for a number of elements by clicking on the (?) symbols. 


This calculation is based on the UK Calculation of Road-Traffic Noise (CRTN) method, with adaptations for New Zealand road surfaces. The calculation is subject to the limitations of the CRTN method, and in particular this result for a single segment of road is only appropriate in situations without complex terrain or buildings, and for a road with consistent geometry and traffic characteristics. In addition to the standard terms and conditions for use of this website, the NZ Transport Agency does not accept any responsibility or liability whatsoever, whether in contract, tort, equity or otherwise, for any action taken as a result of reliance placed on this tool, or for any error, inadequacy, deficiency, flaw in or omission in the tool.