Single Point of Failure

In my line of business, I, and my team, are judged by how often servers and services go down and how quickly we get them restored. I'm constantly trying to make sure there's no single point of failure. There should ALWAYS be a backup. We have to employ tactics that use what the world calls Reliability Engineering. For you non-technies, here's a good layman's definitions

I'm often held accountable on items that fail on me. Sometimes it's people, other times it's a $5 part. Regardless, as I live life, I see single points of failure. Two specific ones are:

In January, AT&T had a single tower in the Charlotte area causing other towers to experience complete outages. I'm guess they had a single point of failure.

The other morning I dropped my daughter off at school. To get to work I have to travel a two lane road. An auto accident on that road forced me to go out of my way about 5 miles. They should widen that road. We'd have other lanes to go around.

My point is... you should always have a plan "b", a backup. Someway to get around the single-points-of-failure in your life. So... Do you?