I saw a FedEx truck blow out a tire on the highway and he didn't have much of a shoulder to pull off you. He put his hazards on and kept driving. I assume to find a service station. Is that what you guys would normally do?
Yes, if you can get off the road, that's your priority. You only want to be on the shoulder if that's your only choice. Sometimes it's not possible, but if it drives, at the very least, get to an off ramp. The shoulder is a nerve-wracking and dangerous place to be.
If can't get off the highway, pull off as far as you can, get out and set up your triangles, then stay in your tractor until help arrives.
It's happened to me three or four times, where the motor quit, and the shoulder was my only option. Most drivers will do what they're supposed to, but it's amazing how many idiots just stay in the right lane when they could move to the hammer lane as they pass you. Most truckers are pretty good about it, unless they just can't move over.