Jamers from San Diego CA on 9/4/2020 1:48:32 PM:
Amtrak is required to take your trike in bike areas if you use it as a mobility device. You may need to have a Disability ID for transit though for that to work. On planes you can check it for free as a mobility device no questions should be asked, but Amtrak might require “proof of disability.” On a positive note, once you have that you can also ride at a deeply discounted rate and a companion gets a discount to too.