Infrastructure and public transport contract price adjustment

Most of the raw data comes from Stats NZ. We use that to generate the indexes every quarter. The exception is the bitumen cost adjustment series, which we calculate and publish monthly.

Stats NZ open data - Infoshare (

The zip folder contains four items. 

Latest values for bitumen cost adjustment series.Latest index values for infrastructure cost indexes - ORIGINAL 1991 series.Latest values for infrastructure cost indexes NEW series.Latest cost index values for public transport.

You can find out more, including reading the procurement manual, on the procurement tools page on See the links below.

Procurement tools page ( price adjustment for cost fluctuation: infrastructure contracts [PDF, 1.1 MB]

Note: file name is 'instructions-for-bitumen-volumetric-approach'.

Adjuster tool ( indices for public transport [PDF, 388 KB]Bus and ferry cost indexation tool (

Data reuse caveats: As per licence. 

Data quality statement: Stats NZ releases the source data that Waka Kotahi uses to generate these indexes. The indexes are fixed every quarter, except for the bitumen series (fixed monthly).

Data quality caveats: See data quality statement.

Photo: screenshot from procurement manual cover, showing roadworks. Credit: Waka Kotahi NZ Transport Agency.

Data and Resources

Additional Info

Field Value
Theme ["geospatial"]
Author Waka Kotahi
Maintainer Open.Data_NZTA
Maintainer Email Open.Data_NZTA
Source Created 2021-12-10T02:30:24.000Z
Source Modified 2024-02-25T19:35:20.000Z
Language English
Source Identifier
Dataset metadata created 10 September 2022, last updated 1 March 2024