Spare Tire....How many of you carry one?

I came across this forum and got me thinking. We just bought this class c and I never considered a spare. First I know it was not with the rig and second I just thought we would use the Good Sam insurance. Frankly, actually with a little embarrassment, I have never changed a tire on a dually so I am not sure how much more difficult it would be. Front tires would be ok. But I agree with the one who said how dangerous it is in the first place to change tires on an interstate. I am definitely doing some rethinking on this. It really ticks me off though that the rv manufacturers don't include one. They do on the fivers and tt"s. The more I get into this class c the more I think maybe I should have stayed with the fiver and just worked through those headaches instead of adding more with motorhomes. Bill