I haven't, but probably will. I do carry a small wallet, and usually keep my ID on my body. A bracelet or necklace would be better.

As 10 Wheels mentioned, emergency personnel may not check anywhere but your neck and wrist for wearable ID. I just got a reminder of that Thursday afternoon when I chatted with EMTs about an ill family member (heat exhaustion) who couldn't remember her address, phone number, etc., and whose ID and other contact info were scattered loosely in a crowded tote bag under stuff she'd just purchased at the store.

My baggy shorts have small zippered or Velcro pockets for ID, but these may not be obvious to folks in a hurry. A bloodied, torn jersey may be cut off and discarded, along with our phones and IDs. In an accident we'll be separated from our bikes so the IDs and phones in and on our bikes won't help.

Having been in health care for years I've seen many folks who've suffered concussions and cannot give useful information to helpful folks who stop or emergency rescue personnel.

While I've never had a concussion, including as an amateur boxer, I should be realistic and admit that's only because I haven't been hit hard enough.