There’s two ways to achieve it; re-introduce the legislation (I think) from prior to the 80s that limited the maximum distance freight could be transported on road. If I recall some documentaries i’ve watched correctly it was removing this restriction that made road transport competitive with rail in the first place and precipitated the decline of TranzRail.
Or, as you say, charge all forms of transport the full cost of provisioning it which would immediately make road transport very expensive. The problem is that would probably cause an immediate inflation bump as a mode change like that really needs careful panning and transition.
I feel like I heard of a Labour plan to build rail hubs. Infrastructure like that is expensive and risky for private companies (because what if there are no customers?), but if the government set it up (say, one near Auckland and one near Wellington), and organised the rail freight between, you could have a really nice rail system set up, with trucks handling just the first and last stretch.
Yeah, and if well designed it potentially is an investment like electrifying steel furnaces. Anything we do that has a big impact on reducing emissions is likely a good thing.
If it follows SH1 (mostly) that would be a great thing.
I would love to be able to have passenger terminals available to travel to Wellington / Auckland