Well, it looks like the bandwagon has turned against Megaproject Support this turn. I suppose we are still at war with the Swamp Folk, and it's hardly the end of the world even if we weren't, probably.
Still, it would be a good thing to have. The tax crisis will probably be resolved through Megaprojects, after all - the Palace, the Census, and then the Law (Iron Age). I feel like a sufficiently massive and comprehensive road network might be put under the label of Megaproject, if Academia Nut was feeling nice.
What I want to do with the roads is somehow get the military involved. The Roman legions were famous for their road construction, and in modern times the Army Corps of Engineers is pretty good at what they do. That would probably mechanically translate into Martial constantly trickling into road construction, which might be a good thing if handled correctly - all other stats overflow into Martial eventually, after all, though of course we haven't really had issues with the main stats overflowing in... a while.