Yeah...or for some reason I am running like I'm waist - deep in molasses, R-E-A-L slow, or one of my legs is numb or something. Or I have no shoes.
That happens to me, too. My theory based on some observations of when I have this kind of dream it that it can be triggered by falling asleep or turning over into a position that slows down the circulation in my legs. For instance one time recently I was dreaming that I couldn't move to my right, and when I woke up I saw I had fallen asleep on my right side with my right arm under me so that it had gone numb. Also, sometimes if my neck is in a weird position on my pillow I will have dreams related to that sensation.
Oh, and I'm always walking somewhere, even in my regular dreams - I seem to leave my car in odd places. A common dream is being stuck on a bad part of town and I have to walk home. Rather boring really ---it's just your garden-variety anxiety dream.
I've noticed that my dreams typically begin and end with me getting on a bus and going home, or something like that; and I've read that a lot of people have similar dreams about flying or turning into a bird; I tend to think walking/car dreams are often related to this category of dreams. My theory on that one is that it symbolizes the transition of the body from waking to sleep and vice versa, with the sense of "travel" symbolizing losing/gaining awareness of the body as one drifts into or out of sleep.
I've read that a lot of people have similar dreams about flying or turning into a bird
Occassionally, I get the classic-Superman gift of leaping (not flying) for long distances. But not very often. :(