Will my living will and advanced directive be used at the trauma center?

Certainly, as long as the trauma center has access to this document they will indeed use it and follow the directions contained in it. That is why it is very important that your family knows where your document is so that they can bring it to the hospital on your behalf. If your personal doctor has a copy of it he/she can deliver it to the hospital also.

If you are in the trauma center and you are critically ill and cannot communicate with the medical team, the contents of the document will inform the medical team about your values (what types of health care interventions you want/don't want in times of medical crisis).