Heavy rail; 50 million
Light rail: 25 million
Freeway:5-10 million
So why aren't they simply doing dedicated roads for transport?
With AI platooning and supervised self driving, "trains" of busses can run along those lines, but split off and merge in from local service seamlessly.
Commercial traffic (even through traffic) can piggyback on low traffic periods.
In emergencies, they are additional roads for evac or supply.
Roads are much more easily repaired and fail less catastrophically.
Electrification of busses is well underway and should be simpler / cheaper for recharging infrastructure.
Platooned "trains" of busses will conserve energy and likely could go 100 mph or more with proper convergent sensors monitoring and maintenance.
Safety should be equivalent.
I suspect there are political nuances where rail gets its own budget apart from roads, whereas dedicated roads get thrown it with general road funding, and then wouldn't get proper funding.