If you keep your tires inflated right, modern tires will blow out less frequently than old fasioned ones. If you overinflate, they can blow, though.

I blew out a rear (tubular) tire on a descent off a mountain pass at 70kph. The tire blew right off the rim and caught between the wheel and the stays. �@That locked the wheel up and I ground about 2mm. off the bare rim as it dragged on the asphalt. The guy behind me said he saw the sparks coming off the wheel.

It took about 10 meters to stop, but somehow the bike stayed upright. It turns out that the gauge on my pump was reading low and I had actually overfilled the tire to 135psi.

Anyway, make sure your gauge is right and use it.