Yes, that is correct. Roads cross the rivers at some places, but then it makes the whole thing useless, as the boats can pass "under the bridge" so to speak, so it doesn't matter if the river beyond the bridge is still navigable or not. So the compromise solution that we'll have in EB (that's not a secret, is it?) is, as I said, that the lowermost parts of big rivers are navigable, up to the first bridge location.