This dream exemplifies the importance of looking at a sequence of dreams: it answers the previous nightmare.
The Dream: I'm in a tunnel. There is a long line of traffic going slowly in the left lane. I follow along at first, then become impatient, wondering why I don't go around the other cars. I pull to the right and pass the other cars, coming into daylight.
Interpretation: In the previous dream, I was waiting for a train (on a fixed track) in a very black tunnel. It clearly wasn't going to take me where I needed to go. In this dream I'm in the driver's seat, controlling my own vehicle, and getting around an obstacle. Something unconscious (on the left) has been slowing me down; I pull to the right (the obstacle becomes conscious). I get past the block and see the light.