When your life is at a crossroads, you have some very important decisions to make about what "direction" your life will take. Will you have a child or not? Quit your job to go to school, so that you can find a better job later, or keep working in the one you're in. Will you take a new job in another part of the country? This is a very common figure of speech.
If you have run out of gas, you have a lack of energy. Maybe you are just too tired to make these big decisions, or maybe you don't have the emotional reserves needed to face up to the consequences of these big decisions. This is simply a metaphor, and not really a common figure of speech.
- For Teachers