First, a Cheers to all who participate in walks/runs for charity causes. But, a big jeers to the organizers for allowing people to spray-paint arrows on public & private walkways! Do you have any idea how much work it is to clean spray paint off sidewalks? Probably not, since you never come back to clean up after yourselves. Each arrow is an hour of scrubbing with eco-friendly solvent. Don't even ask how hard it is to get paint off a wooden bridge or boardwalk. From now on, use duct tape, & please, be considerate & send someone around after the race/walk to take the tape off after the event is over!