They recommend that you raise $100 for the century. Otherwise, it's just a recommendation, registration is $36.

They close down several highways for this including the holland tunnel.
You go up the FDR, around harlem, where there's a mandatory rest stop while they shut down the highway.
Then you go down the west side highway, go flying through the holland tunnel (the best part of the ride), come out in NJ, go up river road, go into palisades park, fly out of the park onto 9W, go up 9W, around the lake, and back.