We sometimes have work trips that are about a 6 hour drive away...some folks drive it, I still fly even with a connection.

I really despise driving more than about 2 hours but will do it if I have to. Once in the 4-6 hour range I may be more likely to fly - depends somewhat on the specific destination, weather concerns, or whatever.

I wish I lived in a place with reasonable rail options as I would go that route often if I could. But it won't happen in this region of the US, not in my lifetime anyway.