You know the tires are going to have to be replaced, so what's the question?

If, as you say, you are riding in fear of a blow out, or, as others have pointed out, you are continually having to fix the flats that accompany worn out tires, how much are you enjoying the ride?

I'm kind of particular about my tire selection so I keep spare tires in stock at all times. When I replace a tire on one of my bikes, I order a replacement tire to have on hand. Same with tubes, rim tape and a whole bunch of other consumables.