It's another question if it makes sense to add that amount of road. It probably depends on the particular case.
And how much money would it cost to build out enough road infrastructure to 'overwhelm all possible demand'? How much would it cost to move the same amount of people via some other form of transportation?
The province of Ontario finds it cheaper to run an entire railway (GO Transit) compared to being able to build out enough highway infrastructure (and it's not like they've stop building that):
* https://www.youtube.com/watch?v=vxWjtpzCIfA
And that's just the road infrastructure: what about things like parking space at the destination(s) of where all these folks are going? How much area would have to be bulldozed for all of this?