One thing high speed rail, or any rail for that matter, requires is dense walkable cities. If the rail link requires driving to the station and renting a car a

One thing high speed rail, or any rail for that matter, requires is dense walkable cities. If the rail link requires driving to the station and renting a car at the destination it's not going to be comparable with one where you can walk or take the tram/subway to move within the endpoints, and there it loses the appeal of convenience. The best thing that trains offer is direct connection from one city centre to another city centre. These centres need to be such that they have places to go to, reachable by at most public transit and a bit of walking. If they aren't then your single train trip effectively becomes three separate trips.