The playground across the street from our house has two sections, one for toddlers and one for bigger kids. Of course, Noah refuses to stay on the toddler side. I tend to let him run around the big kids side (assuming it's not too crowded) and deal with the playground equipment that is too old for him by just refusing to help him. This has worked pretty well for us - Noah gets to play on the bigger slides that he can handle no problem, and is self-regulated away from the equipment he can't manage. I figure he can't fall off the ladder and break his neck, because he is clearly too young to get up the ladder by himself.
It seems it may be time to revise that strategy.