Your neighbors are more likely to be charmed if they know what the hell is going down. Be proactive or risk having to tell it to a judge.
A letter distributed to neighbors around the starting line a week before your event can go a long way. You can even invite them to join the event at the starting line or at the checkpoints, or donate a few non-perishables towards the food drive. This is a fun spectacle, perfect for bringing the kids out to watch. And, it’s a good cause they can embrace. Leverage that. An engaged, welcomed community is a happy one.