The limitation with TrueCrypt (as I understand it) is that because it "mounts" the encrypted portion of the USB memory as a new drive on the computer you have to run it under a profile that has administrative rights. I think this could cause some problems accessing your data in an emergency because the government or public computers that you might use in a "re-establish your identity" situation probably won't have admin rights enabled.
Oy here we go again.
Encrypted digital data is NOT - not not not not suitable for emergency records. In fact, expecting your USB drive to be in any way useful in a real emergency is at best a fantasy and at worst dangerous.
I was a firefighter for six years, I did many rescues,auto extrications, etc. Of the ambulances, fire trucks, helicopters, rescue vehicles or command vehicles I worked in and with, of the few with computers on board, NONE were able to read a USB key.
At the emergency room, 0% of the computers in use could read a USB drive.
I'm now the emergency management coordinator for a local township, but I'm training up to go further. There's no model in the various national response plans and communications plans to utilize data stored on unknown devices that are handed to you by someone.
Further, a scan of a driver's license is not recognized by any agency as a legitimate identification, any more than a scan of a credit card would be accepted at a store for payment. A scan of a birth certificate? Useless.
You'd do better simply writing a list of document identification numbers, expiration and the like on a sheet of paper and using that for your emergency records.
We can go into medical records deeper later, but I asked a Dr. to email me the MRI of my head and they simply laughed at me. "No, this system will never touch the internet" and so I handed them my USB drive and they were like, "You're joking right?"