If you find yourself trapped in a cul-de-sac, or dead end in a dream, it can be a message that you are working hard to achieve a goal but that your efforts are futile. It is possible that you are trapped in the same, unproductive pattern of behavior, doing the same things over and over yet not getting any closer to your goal. Your dream is telling you that you should step back, take a look at what you are doing, and try to see if there is another way to achieve your aim.
When you are in a dead end, the only way you can get anywhere is by moving backwards, so a dream of a dead end can mean that before you can move ahead in life, you need to look back at the lessons you have learned from the past.
A dream of being in a dead end can also mean that you are being too idle and you need to take action.