A broken spoke could happen on a 3 mile ride - when it's time for it to go, it will go.

If you're on 32 spokes per wheel then it's not a huge concern, though carrying a spoke wrench is a good idea if you want to be able to get home should a spoke break.

And if you don't want to carry a spare spoke, check out the "fiber fix" temporary spokes, they're pretty cool.