Driving is much more expensive. You can buy a round trip ticket from Boston to Los Angeles today for $238.
If you drove a magic car that got 35 mpg and needed no maintenance or insurance, and you used a magic credit card that let you pay only $2.50/gal for gas, and you didn't need to stop for sleep for the 90 hours and 6010 miles of the round trip, or need any food for the same period...
...it would still cost you $429.28 to drive.
You could pack yourself into a box and ship yourself as freight. The round trip would take 8 days. Assuming you were small and took only enough luggage to fit into a 200 lb. package, it would cost $792.46.
If 8 days in a box is undesireable, you could ship yourself as overnight freight. The round trip would then cost you $2041.60.
The passenger airline industry in this country is completely broken. Freight pilots are paid 3 to 4 times as much as passenger pilots, their companies are making record profits, and no one is asking them to take pay cuts.
Think about that.