Make sure you have a decent spare and all of the tools necessary to change it out. A bottle jack and jack stand, lug and torque wrenches, tire repair kit and even a small portable compressor are all must haves. Trailers are notorious for picking up road junk, it is usually the right rear that catches the worst of it.
Having these items isn't much help if you don't know how and have experience using them. Practice changing a tire in your driveway just to confirm that you can do it quickly and safely as the side of the interstate is no place to linger.
:C
