We could ask why Christian's often travel on Sunday using any mode of transportation. I think it is because Sunday to them is a "down day" and they aren't losing income anyhow since they don't work on Sunday, so why not use that as a day of travel. That way they can be back at work on Monday. From a business standpoint, it makes sense. But I don't think they are aware of the personal values that are driving these judgments.
There is the story about the man in a poor country who promised God that if he gave his hog some piglets, he would give one to the Lord. (His hog was his sole source of income, and it wasn't gestating.
The hog got pregnant and the piglets were born. The owner was excited. One morning he went out to check on his hog and her offspring and found one of the piglets dead. He left the shed in a hurry and ran in to tell his wife the God's piglet died.
The question of course is, "Why is it that when a sacrifice needs to be made, that God needs to make instead of us."
There is a sizeable percentage of Plain Anabaptists (probably the majority) who avoid extensive travel on Sunday and rather travel on Monday.
