> If the roads were designed with enough capacity and planning in mind such that groups of vehicles are not stuck driving 15 MPH on a 70 MPH speed limit stretch

> If the roads were designed with enough capacity and planning in mind such that groups of vehicles are not stuck driving 15 MPH on a 70 MPH speed limit stretch of highway for 30 minutes or longer every day, that'd be fine. If you build that, then more people see that there is a nice quick road between where they work and a place where they can buy a more affordable home. The road gains more commuters until the congestion returns. Your other suggestions are more scalable. If housing is expensive, there should be more, denser housing. If commutes are long, we should be zoning such that houses can be near workplaces, and conversely workplaces can be near housing. If you create pockets of higher density housing and workplaces, instead of only building large swaths of low density single-family residential, you can preserve the options to live in a city, a walkable town center, or a more quiet location, while still having dense enough groupings to make transit lines viable.