theres a speed camera either side of the rakaia bridge that is not showing up on the map
Are you referring to these cameras?
If so, they look to be related to checking commercial vehicle weight. NZTA have more information here:
https://www.nzta.govt.nz/assets/Commercial-Driving/docs/commercial-vehicle-safety-centres/Rakaia-CVSC-newsletter-July-2023.pdf
Not able to see anything about a speed camera in Rakaia on the NZ Police web page either:
https://www.police.govt.nz/sites/default/files/publications/scep-all-sites-location-and-gps-co-ordinates-feb2024.pdf