I did some cross-country hitchhiking in my youth. I forget why, but tractor trailer drivers where generally prohibited by laws or company rules (probably both)

I did some cross-country hitchhiking in my youth. I forget why, but tractor trailer drivers where generally prohibited by laws or company rules (probably both) from picking up hitchhikers. Moving trucks, however, were the exception. For some reason they were able to pick up hitchhikers and I rode many miles in them.