kWh/passenger-mile, which, even if you assume both have environmentally-equal power sources, means environmental impact.
Probably also easier to keep other vehicles off your “dedicated” lane with a train.
High speed trains are three times as fast.
A 100mph train (again, not a modern high speed train) with limited stops would beat the car. Not sure the track could be built for this in this geography, however.
100+ mph roads aren't unheard of (see autobahn). Neither are 100+ mph trains. The fact that neither is available is frustrating.
This whole "one mode to rule them all" attitude- common in American news media- is toxic. Cars, trains, buses, planes, and more all have their place.
Train service between the two cities, meanwhile, is much more reliable in how long it's actually going to take.