Wow, 100,000! that is impressive. You'd just about fill the 7-1/2 mile stretch with that many people.
That's a nice number, but it didn't look like anymore people than we have seen here in Portland on similar length 'closed streets' rides or on the 13, 25, 38 miles Providence Bridge Pedal routes that draw 10-20,000 (2nd only to the 5-boro ride in NYC).
Hope to personally participate next time to gauge it for myself.
Lou