You will most likely be stopped from crossing the bridges if your vest isn't showing.

I have done it every year for the last couple years. It's like $40 once a year, which is totally not a big deal and you get to ride with thousands of other people on places you never will otherwise.

If you do go, it is stop and start until the teens, with another hold up for a few blocks before the park. I guess this is to space out the ride a bit. After that it tends to be pretty much non-stop, with one or two occasional traffic stops. Your best bet is to get near the front of the pack at the beginning and keep up a good pace once it is not so congested.

The worst part of last year was waiting for the Ferry. Something went wrong and they didn't have as many special boats as they needed. Or something.