I was driving south on mopac highway approaching slaughter lane; there the road rises in such a way that drivers have a pretty clear view of a large part of the sky to the south and southwest. the sky was clear, and the object pretty noticeable. i first though it was a sun dog, then thought it was a jet leaving a small contrail. however, as i watched it, i realized it wasn’t moving as a jet would. it seemed to me that it was moving extremely slowly or motionless. i would describe as looking like a jet-type object creating an extremely wide but also extremely short contrail. i don’t think it was moving. i was curious what it was, but had no other emotional reaction etc. i turned off of mopac and heard west on slaughter lane. there are more trees and commercial buildings and i could not see it anymore. it was below the horizon. i live within a mile of that intersection and by 2:45 i could not see it in the sky there.