This manual describes the current methodology for traffic monitoring, the technology involved, conventions, survey guidelines, calculations and an overview of the software system.
Our open data portal has a number of traffic count-related data sets, from quarter-hourly historic datasets to daily-updated datasets (API or CSV) and more.
Our interactive map displays traffic count sites and estimated traffic volumes for state highways.
For sites that use dual loops classification is by length. Vehicles with a length of less than 5.5m are classed as light vehicles. Vehicles over 11m long are classed as heavy vehicles. Vehicles between 5.5 and 11m are split 50:50 into light and heavy.
The NZTA Vehicle Classification Relationships diagram below shows the length classification (typically dual loops) and axle classification (typically pneumatic tube counts), and how these map to the Monetised benefits and costs manual, table A37, page 254.
For the full TMS classification schema see Appendix A of the traffic counting manual vehicle classification scheme (NZTA 2011), below.