On the interurban trail stenceled on the ground. Is it Urban Way Route? It is driving me crazy :eek:

it's on parts of the green river trail too, and i've wondered the same thing!

anyone know the mystery?

I'm betting it's route markers from the In Unity We Run marathon.

These go to the Duwamish trail and last one I saw was just joining the Alki trail, wondered the same thing while riding last weekend.