I should have said that it's dangerous (to the piano) to move a piano with the sound board horizontal. Spinets and other uprights should be moved upright, and grands should be moved when they are on their side.
However these were only 300 dollar pianos** and I couldn't afford to also pay a mover. So I went only about 10 MPH on the rough parts of the road and only 25 or a little more on the very smooth parts, looking ahead to see if there were any chuckholes.
**The Wurlitzer sounded very good when my friend got it. The Winter sounded bad, even to me, when it came to my house. Maybe I wouldn't have bought it if I'd known a piano could sound bad to me. None other has, before or since. But a cheap, used piano can sound very good.That's pretty funny.