I know its not
Interstate Business Route Appreciation Week anymore, but while that was ongoing, I was early through a three-week overhaul of the
Business Route Guide. Just completed the last of those page revisions, which included going through every route's guide and trying to verify whether the loop or spur was still signed, decommissioned, or switched to local control. Additionally the old picture page, with photos contributed over the last 15 plus years, was retired, with most of the photos posted there moved onto the individual route pages. Also added a few taken from recent roadtrips and scanned a few maps too.
Went through some of the posts here and added the proposed routes for the Oklahoma City Boulevard Business Loop for I-40 mentioned by Eric (okroads) and the Indian Creek, MI one cited by Andy. If I missed a route, got something wrong, or forgot to upload a file, please let me know here.