My megaproject ideas are mostly pretty standard. I'd build a high speed rail network across North America, and build and expand metro and regional rail systems in and around every city. I'd turn all cities and suburbs into fifteen-minute cities. I'd decommodify housing, and build ten million units of public/social/non-market housing, mostly three bedroom units. I'd link those last three policies together by building TODs around the new Metro and rail stops. And I'd build bicycle networks in every town and city and connect them to the TODs. I'd build bridges and walkways across skyscrapers. I'd put a bidet in every American toilet (uses less water than toilet paper apart from being more comfortable). Fiber internet in every home. A heat pump in every home. An induction stove in every kitchen. Phase out fossil fuels and power everything with Pumped Storage Hydropower and Geothermal. I'd make the US go Metric.
But my truly crazy, obsessive idea would be to bring back the French Revolutionary calendar. Or I'd purge all French influences from English.
Create a large network of state and/or cooperatively owned cannabis farms to mass-produce hemp for industrial purposes, and every strain of quality marijuana known to man. You think the weed's too strong these days? That's ok, the state will devote its resources to developing 10% THC strains that taste like a gourmet meal. You want to be sent to the moon? Why yes, there will be 99.9% pure concentrate oils widely available.
Just as the USSR had an alcohol ration, there will be a mids ration available for all. Any unclaimed rations will be distributed to the gulags to forcibly pacify political prisoners. While high and marginally more open-minded, they will be made to play video games where every character is a black lesbian and all the messaging is based on post-colonial theory. Only after their daily shift constructing and tending the farms is finished, of course.
Any questions?
Also linen! Massive state linen and wool production so no one ever has to wear cotton, the shittiest fiber, again!