At this point, it would almost make more sense to build separate HOV lanes on the interstate reserved for self-guiding automated buses that run at 120+ mph. Probably cheaper and much much more innovative.
“build separate HOV lanes”
No, use existing lanes. Increased bus ridership will decrease the number of vehicles on the roads.
Another thought: allow “jitneys” which I think are independently run buses, vans, etc. Right now the regulated public transportation organizations keep out these independents. That establishment would tell us that the independent transporters would be too dangerous.