Hi Rico,
Just to add some detail to Hoov's comment regarding roads, I have attached an older post that I wrote when a similar question was asked some time ago. I agree completely with what Hoov has said and the following just gives you some idea how these things can evolve:
I am not too familiar with how a railroad might be shared but I am very familiar with how resource extraction roads are usually shared.
Typically, if a road is built to access resources in a remote area, whether mining, forestry, oil or gas, then the various companies (and the gov't.) that might need to use the same road will sign a joint road use agreement of some sort. If they all know that they want into the area in advance, they will often jointly fund the cost of construction based upon the relative amount of resource that they will be hauling over the road. Further to that, there will be a long term maintenance agreement where the users contribute maintenance costs for the road on the same basis of relative use. It is not too difficult to determine how much a given company uses a road by simply taking the delivery results from the truck scales at some point in the system. Normally, in remote Canadian operations, the provincial government is a part of the road use agreement equation because the road runs through public (crown) land and thus the government has a significant amount of control and input into how the road will be administered. They also will often contribute construction funds in the right circumstances (which would be the case in the ring of fire).
Since the road is on public land and potentially provides beneficial public access to places like remote communities, the public is usually allowed more or less unfettered use of these roads if they need it. Often there are just some safety constraints placed on public users to reduce accident potential when resource deliveries are at high levels. I am not aware of tolls ever being charged for such use. Essentially, the roads are paid for by all of the natural resources that roll over them. The public users benefit from the road being there, and the industrial users benefit from both the resources and the government funding and/or reductions of royalties in some cases to help them build and maintain the road.
The laws and/or regulations relating to joint road use are not necessarily all that clear. However, one usually finds that the players come to an amicable agreement and things move ahead (i.e. there is always some negotiation around all of this). The good news is that this is very common in Canada and there are many thousands of kilometres of resource roads throughout the country that have such agreements in place and are completely functional. I have, during my own career, written and signed several of these with users including the provincial gov't, and multiple resource extraction companies in both BC and Alberta.
Just as an FYI, in Canada, all natural resources are under provincial control and the provinces are the sole beneficiaries of royalties, stumpage, etc. that come from their resources. The federal government has no say at all in how these matters are managed by the provinces. This has been the case since 1930.
I hope this is helpful,
RHammer
