I've learned the trick of lifting up the front wheel of the tricycle by pushing down on the attached pole. This means that the tricycle "driver" can't steer. Of course, the rider can't pedal either, but in Julia's case, she's not pedaling much for the long haul anyway. So a little lift from me means that the two of us can cruise. I was running at a decent pace, sweating, in fact, and Julia enjoyed the fast ride.
The preschool girls stayed to the right on the path, waited if they got ahead of the moms, and put the breaks on for the downhills and sharp turns. In "Fit Family" I discuss how bike paths can have some potential cons, if they are busy and you are trying to get a child acquainted with riding. Yup, I've had some close encounters with kids and potential collisions on the bike path, but not this time.