For comparison, math for the Villach to Edirne trip comes up with USD 158 in gas for the average US car mileage and gas price for 1400km, versus USD 443 for the car + person tickets.
Driving 100km on a nauseating mountain serpentine can easily take 2-3x longer.
But yeah, 300 dollars in Turkey is a lot of money that most people will be willing to save.
In my own little world, I don't worry too much about 1400km in one day. I'll probably stop and take a long break at some point (and maybe catch a nap), but I don't think I'd be willing to pay $300 to avoid the drive.
It's a long day of driving, but I enjoy the diversions on trips like that. There's a whole world of stuff between A and B and it's nice to be able to stop and take some of it in whenever I feel like it when driving alone, which I can't do with a train that has my car loaded on it. (My solo driving style suits me very well.)
Or: With passengers, we can take turns driving and the cost per-head decreases instead of increasing.
I’ve driven 680 km each way on interstates to my in-laws’ home. There on Friday, back on Sunday. Had to drive because I was bringing gifts, way too much for air travel.
And to most Americans, that’s not a particularly long drive. It’s all a matter of what you’re used to. I’ve done 4800 km in eight days and didn’t do anything but local driving on three of those days. That’s a bit more than Madrid to Berlin and back. It’s a lot of driving, but it’s definitely doable even if you’re not twenty years old.
(Though for a journey this long people with multiple cars would probably be taking the larger one.)
The train costs more, but means families can play with their children (around a table) rather than having them stuck in the back seats for hours, and probably part or all of the journey is overnight.