Welcome back.
I figured you were gone for good. We're not here to beat folks up (Unless they're ready to pick a fight, then we are happy to oblige.)
Learning what is and is not legal in regards to furbearers is one of the first responsibilities of any trapper. Your idea was not wholly unfounded, using "waste" furbearers to practice skinning and fleshing is a good idea. And it would seem logical that one killed along the road would be a good place to start. However, the law says otherwise.
If you want the actual, technical rule for my state of Ohio, it is not legal at any time to pick up a roadkill, with the possible exception that the law enforcement folks give you a permit for it, like they do road killed deer.
In Ohio "methods of taking" for furbearers and game animals are cited specifically in the code/regulations. Since "roadkill" is not listed in those regulations, it is illegal to possess an animal killed that way. Now, in all fairness, I don't know of anyone who has been cited for picking up a road killed furbearer
in season, but it is still technically illegal.
Hal