Brakes and Nightmares

I have been having reoccurring nightmares that my brakes go out on my car. My first dream was not that bad. I hit my brakes and I was only able to slow down to 10 MPH. So therefore, I ran a stop sign on level ground. However, this last nightmare I had, I was going backwards down a cliff and my brakes didn't work at all. To make matters worse there was a fast moving river at the bottom of the Cliff that I landed in. Then I had to swim out and I was drowning.
Why am I having this dream? I am not one to read into dreams and think they mean something. But, why is it that I dream of the same thing over and over and each time it gets worse?