That's really interesting, PaintHorseMares. My horses got out last summer. The quarterhorse gelding I had then was very curious and he found a way to open the gait. Anyway, he and my friend's thouroughbred gelding were running down a county road at evening comute time. When the county sherrif pulled up to the side of the road and stepped out of his car, to figure out how to catch the horses, my Archer ran right up to him. I believe my horse asked could he see the sheriff's gun; would he please put the lights and sirens on and could Archer ride shot-gun. He was just so curious! A funny horse.
Winter Filly, you're right. It can be really scary. I'm lucky in that our roads are quite wide with nice shoulders on them. And there's always the ditch to ride in, if things look too iffy.