Haunted Cycle Route

Most evenings cycling home up the Clyne Valley cycle path, and particularly if I don't have my full beam on, I see the spectre of a ghostly jogger. At first I think I see a man running in the dark, ahead of my light, but I never catch him. He's wearing a light top, I can see the shape of his shoulders, and he's bobbing up and down as he runs. This occurs just after Killay. I have seen this phantom on at least three occasions.

Sure, I could apply the scientific method and test the hypothesis that in fact what I see is a light patch a long, long way ahead of me as the trees thin around the path before it reaches Dunvant, and that neither my eyes nor my brain work in quite the same manner in low light as they do in full light. I could stop my bike and see if the bobbing motion stops, and I could put on my full beam and see if that changes my perception. But then I wouldn't have a very interesting story, would I?