As someone who has done about 10 50+ miles in the park I must attest.

It is really annoying to ride that kind of ride in the park during the day on a weekend this time of year. Especially w/o brakes. There are just infinite numbers of idiotic parents letting their little little kids run out onto the road. I have had a number of close calls that left me really shaken -- feeling like I almost killed a kid.

Just my warning. I ride laps all the time, but on the long rides you get tired and you start to go too fast, etc.