I live next to a busy highway. I can't see a splat cat, I couldn't deal with that. I rode in the back of the station wagon with a kitty when I was a kid because I had climbed up the old Chinese Elm to see Cinders and he jumped down and ran in front of a car...it was one of the most horrible things I've ever seen. I still have the picture in my head. He was of course put to sleep and I was traumatized for days. (When I went back to school Sister Frances yelled at me that animals don't have souls and I would NOT be seeing my cat again. THis was the only time I remember my mom fighting my battles, but I was in second grade and my mom recalls she ripped Sister French Fry a new one.)
My cats don't go outside, but they have the run of the screened in front porch. I never thought of it as cruel to keep them in...they run and play and seem happy. Now I feel kind of bad.