Why do I keep having this kind of dream?

Its not the same dream but the same thing happens. I'm driving through an underground tunnel that's kinda hilly and curvy. Its made of rock and is just wide enough to drive in, no chance of turning around. In these dreams I always make a joke saying "It would suck if my car died on me in here and I'd be stuck here." or something like that. Also its at night when I'm driving in these dreams. I realize when I wake up that I wouldn't consider driving such a tightly one lane road, but I keep having this kind of dream and it feels very real in the dreams. If someone could help me I would greatly appreciate it. Thanks in advance.