Compare driving and flying costs.
The drive-or-fly decision turns on two numbers: how many people are travelling and whether the drive needs an overnight stop. Airfare is per person, so a family of four multiplies it while the car does not — that alone flips many trips toward driving. But once a journey is long enough to need a hotel night in each direction, driving picks up a large per-person-independent cost that often exceeds the fuel itself. Airport extras — parking for the week, transfers at both ends, checked bags — are the line most people leave out, and they routinely add 20 to 40% to a cheap fare.
Drive vs Fly Cost
Driving = round-trip miles / mpg x fuel price + overnight stops x 2 x hotel rate; flying = airfare x travellers + airport extras
Usually beyond 600-800 miles for one or two travellers, because the drive then needs an overnight stop. For four or more travellers, driving often stays cheaper well past 1,000 miles.
On the flying side: airport parking, transfers, bags and seat selection. On the driving side: overnight stops, meals on the road and vehicle wear at 15-25 cents a mile.