Ahhh, I remember when the cops started enforcing bike speed limits in parks and on MUP's in CO. You are only nimble at 25 mph until you scare someone into your wheel. Though it alternately infuriated and provided laughs there is no doubt it settled everyone down enough to make use of the public trails in multiple ways. If you can't take a group of kids down a 13 mile trail both ways without serious incident you should contact the authority who spends their budget to build and maintain the trail system. That is if you are sure that you were making all reasonable attempts to corral your rolling blockade so others could pass and not taunting them.