Data is increasingly important in underpinning the New Zealand transport sector’s approach to consistent levels of service, asset management and investment decision making.
The Road Efficiency Group Te Ringa Maimoa (REG) supports the sector to improve the quality of transport-related data for effective evidence-based decision making and help lift investor confidence.
The objectives of the REG data quality project are to:
REG established a framework to nationally measure data quality in 2014/15. This has since been used annually to assess the data quality of each RCA including Territorial Local Authorities, DoC and Waka Kotahi. The framework interrogates a targeted sample of data to flag potential issues with how the data is being collected, managed and maintained.
The framework consists of a suite of metrics that interrogates a targeted sample of the data that supports our asset management processes. It is not a complete data quality check or validation of data managed and maintained by each RCA. It should not be used to replace quality control/assurance checks required as part of adding, updating and deleting records in your asset database.
There is a separate suite of metrics for TLAs (including DoC) and Waka Kotahi. Many of the metrics are common across both, however, there are a small number which differ due to either a difference in the data source or asset portfolio.
Each metric has been selected to test a cross-section of the data looking at data quality in terms of accuracy, completeness and timeliness.
The data quality framework and quality dimensions are further explained in the online resources.
Data quality framework overview [PDF, 460 KB]
Data quality dimensions overview [PDF, 461 KB]
The framework and metrics are continually evolving and enhanced to provide more meaningful results.
Framework and metric enhancements
Details regarding changes at a metric level are available within Transport Insights.
Data quality metrics library(external link)
The data quality of each RCA, including Waka Kotahi state highway region, is assessed annually and reported. For 2022/23, a framework consisting of 71 metrics for TLAs and 62 for Waka Kotahi assesses each RCAs data quality. For each metric, the RCAs result is compared against the distribution of all RCAs across New Zealand and the expected standard. For TLAs and DoC the comparison is against other TLAs, and for Waka Kotahi regions the comparison is against the other state highway regions.
The asset management data quality report includes an overall ‘score’ which is weighted by a level of importance, that indicates the overall quality of data.
Asset management data quality score calculation overview(external link)
