I admittedly found my favorite evening commute route thanks to work being done on the Mt. Vernon Trail. A relatively short section of it was temporarily replaced by a mulch path while it was being moved a bit further away from the parkway and straightened to solve some line of sight issues. Some local cyclists hated the mulch path so much they started a long thread on the WABA forum about alternate routes just to avoid it. One of those routes is now my new fave - I just leave the MVT a little earlier than I did before.