Weirdly, when I was doing my MPA at Fort Leonard Wood (Webster University), I did a paper on this subject. Missouri has really, really bad transport.
I’d rather drive myself than risk sitting for an extended period beside something that smells foul and bumps up against me. (The last time I took a bus, the fellow beside me pissed himself.) I much prefer driving myself, stopping where and when I chose and being able to fully recline and snooze comfortably, listing to a CD or radio without headphones, breathing clean air, not having to worry about luggage, and not being annoyed by others.
For a trip that is too far for me to comfortably drive in one hop, a plane will get me there much more quickly than a bus, and at the destination there will be a car rental available, whereas with the bus, there more than likely will not be a car rental on site.
The Grehyound Bus Museum is well worth visiting: http://www.greyhoundbusmuseum.org/
It gives insights into how America grew. Quite inspiring.