I find it is better to just handle it myself in my own way and if it works great and if it doesn't then involve the parents because most things are daycare specific. So what if parents let him run ahead on them to the park what you do at daycare are your rules and he must follow them. Tomorrow he will be leashed/harnessed whatever is the proper term for tied to the stroller for the walk - he has lost the privilege of walking like a big kid so is treated like a younger child that doesn't know the rules yet. Do not let him ride but limit his ability to run ahead. Let him earn the privileges back. This is a safety issue and you will be liable if he darts across the road - not a risk I would be willing to take. Rule is simple and age means nothing - If I do not have voice command of you at all times then you are in the stroller/wagon, or secured to such plain and simple.