Depends on the day. There aren't a ton of crowds in the park on a weekday, and as you'd expect there are more people on a weekend ... 'cause it's a park. We spent time there on a Sunday in the morning and I definitely never considered it unsafe for kids. In fact, there were a bunch of kids on bikes and everybody seemed fine. Let's face it, unless they are new to biking, most kids handle their bikes better than the average desk job adult. I seriously wouldn't worry about it, but heading there in the AM if you're going to be there on a weekend is probably a good idea either way.