Here's the Greyhound bus baggage info:
Greyhound baggage restrictions:
* One (1) piece of baggage is checked free of charge for adults and children. One (1) additional piece of baggage may be checked for a charge of $10.00 for adults only. Baggage carried beyond two (2) pieces will be charged based on Greyhound Package Express rates. One (1) small bag up to 25 pounds can be taken on board for each adult or child. Carry-on bags must fit in the overhead compartment or under your seat.
* The maximum allowable weight for checked baggage is 50 pounds per individual piece of baggage. A charge of $30 - $40 (depending on the distance traveled) will be charged for any baggage above the 50 pound limit.
* Baggage must not exceed 62 inches when adding the total exterior dimensions of the piece (length + width + height). A charge of $30 - $40 (depending on the distance traveled) will be applied to any baggage above the 62-inch limit.
o Packaging exceptions will only be made for the following items: bicycles, skis and ski poles must be packed in wood, canvas or other substantial container, and securely fastened; towing equipment must be enclosed in rigid containers or wrapped in a strong material such as canvas and securely strapped or tied. Towing equipment is limited to 100 pounds actual weight. These items are not exempt from oversize charges.
* If bags exceed maximum size and/or weight, customers must ship the item via Greyhound Package Express.
It has the same 62" limitation, although the oversize charge doesn't seem very bad.
I don't think I have to worry about TCA though for busses at least.
Basically I want to finish section 7 of transamerica trail in one trip and each of the 4 western express trails. I'll do them one section at a time ~300 miles at a time is fine by me. So, I'll probably be taking the bus to get to/from those end points from Colorado Springs. But, after those are done I will probably investigate other trails that I would probably want to fly to/from the endpoints.
Clearly being able to fit my bike and equipment in two boxes that meet the 62" requirement, that I could take with me on the bike, offers me the most flexibility.