As for the helmet questions, I asked my mother this and she gave me a long answer about how the abrasions on the helmet and how deep it goes can tell the doctor a lot more then your head can. She gave me a more complicated response, it's just it was hard to take what she said and immediately repeat it.
Actually, you can reliably learn almost nothing from looking at the helmet. For example, in my son's wreck that put him into a coma, his helmet had not a single scuff on it and yet he almost died. Nor was there a mark on him anywhere his helmet was. I had a terrible bike crash, landed on my helmet and there is just the tiniest scratch on the helmet. Conversely, I've seen many ski helmets literally split in half and there was not a single mark on the patient nor did they sustain a brain injury. I've also seen brain injury patients near death with patients wearing a helmet that looked just fine. And I'd say I've seen them in about equal proportions. Looking at a helmet is interesting but not very useful in terms of determining what happened in the head. In point of fact, if you want to know if you helmet is ok after a crash, it needs to be verified by the manufacturer simply because you can't tell if it's ok or not by simple inspection. Most helmets are designed to stop an intrusion of an object from damaging the integrity of the containment of the brain. They do little to nothing to prevent DAI (Diffuse Axonal Injury) or "shaken baby syndrome" and, IIRC, happens at relatively low speeds and energies.
Again, in a 1st responder situation, no one is examining the patient for status on blood borne pathogens prior to treatment. If it is an emergent situation, you glove up and get to work. There is no protocol that I know of that says you treat a patient differently. In order for the 1st responder to understand it before you work on them you'd better stencil it on the patient's forehead and have a T shirt that says that's the issue with lettering front and back because assessment starts as they are approaching the patient and once they touch them, they are exposed.
OK so I got some dogtags for $10 shipped from Mydogtags.com. On one I have my name and a cool motto and on the other, 2 emergency contacts and abbreviations for:
-Date of Birth (DOB 'xx)
-No known allergies (NKA), -No known drug allergies (NKDA),
-No known medical history (NO MED HX)
So the important dogtag has this on it:
NO MED HX
5 lines of simple information enough to tell emergency services who to call and that to not worry as much about whether or not I'm going to have a fatal reaction to some drug or treatment.
I do also carry my ID but I think they are more likely to find the e-contacts on a dogtag than on some card that might get displaced in my wallet.
what is this 'road tax' you speak of?