I run part-time in a system that services a rural area of Ohio. We have 5 stations with 5 staffed trucks, and two back-up rigs available if we need them. We aren't a full-time department, but are a part-time paid service. None of our personnel is full-time, and as long as there are two EMT's on the truck regardless of certification level, the truck is in service. To allow for ALS coverage, we created a roving medic/county supervisor that oversees EMS operations, but also responds as a medic. It works great for our county. If the medic gets there, and sees that he isn't needed, he marks in-service. If there is a medic on the truck, and he needs help the medic rides in as a second medic. If you want further information on our program feel free to ask, and I will see what I can do to help.