I have just read the now locked 'Best GPS Live Traffic Information' thread.   As far as I can tell, you can see the TomTom traffic information for anywhere in NZ without an account by going to the MyDrive page

https://mydrive.tomtom.com/en_nz/


This shows two separate roadworks and a single lane, in central Wellington without being logged in



I think that the difference is that after I log in, I can click on the road work icons and get more information, like how long it is.