Is There An Exit On Every Station?

The startup dilemma: Your project is at a "station" waiting for the next "train" to take it forward, is going to take some time. Sometimes trains are delayed, or even canceled. Should you exit now or wait? Let's assume that you decide to invest the time, take the risk, and wait. Will you have an exit opportunity at the next station? And if so, will it be better then the one in front of you?