I don’t think there should be an issue with the licensing, since this isn’t going to be much of a design job - primarily it’s trying to print a large-size map (about 20 miles of road) with the sort of small, side-road details that web maps typically hide at that zoom level. I think that, being essentially just a large scale print for bus drivers and schoolkids to find the pickup/dropoff points, it falls within the safe boundaries of fair/non-commercial use. Of course, if there’s a line I’m blindly treading on, please let me know. While I don’t imagine Google would file a suit against a rural school district school bus line or the print shop that enabled them, if they did it’d certainly be no fun for anyone.
I did go through the list of permissions/exclusions you linked, and the only line I found that caused me some concern is Section 2, Subsection D here: “[you may not] use Google Maps/Google Earth to create or augment any other mapping-related dataset (including a mapping or navigation dataset, business listings database, mailing list, or telemarketing list) for use in a service that is a substitute for, or a substantially similar service to, Google Maps/Google Earth” - but I think labeling a bus route as a competing service to Google maps is a bit of a stretch.