Originally Posted by rickair7777

Generally, airliners vs. car is about a wash on fuel/carbon for a given trip assuming...

1) Traditional IC engine car
2) One pax (driver)
3) Reasonably full plane

If you add additional people to the trip, the car is more efficient. Also hybrid/battery cars are more efficient. An empty plane is not efficient.

A 50-seat RJ is somewhat less efficient than a NB. WB's are more efficient than a NB, although you'd have to compare those to a boat, not a car.

The kicker of course is the time factor. Many, probably the majority, of RJ routes (especially 50-seat) can be driven in a day or less. The real advantage to a lot of short-haul RJ service may be the small-town airport environment... park next to the terminal, walk in, breeze through TSA. A lot of people pay for the RJ connector just to avoid driving, parking, and TSA at the hub. My parents are about a 2-hour drive from the hub, and that's what they prefer. When frequency gets cut (it seems to come and go at their town), they'll drive rather than spend five hours of airport appreciation waiting for their connection. I do the same when I visit, rent and drive the last leg if the connection time is excessive. In the turboprop era there was a flight every couple hours, basically a small prop-job flew back and forth all day.