This is really dependent on how many people are taking the same trip you are.

There’s a rail line that goes very regularly between my state capital and my state’s eponymous megacity. (And more along the entire corridor on south to the national capital). If it’s just one or two adults doing that trip it’s cheaper to ride the rail, since the two round-trip tickets cover gas, fuel, tolls, parking, and depreciation. Not so if it’s enough people to fill the car.