Twice a year Times Square gets closed to traffic: on New Year's Eve for the ball drop and party and on the Sunday nearest St. Patricks Day for the NYC Half Marathon.
I ran the race this year with 25,000 of my closest friends. More entered but there was a lottery to get in. The BEST part of the whole event was running out of Central Park straight down 7th Avenue through Times Square--it is really cool to run down the middle of 7th Ave. but not a good idea most of the time.
Here's what the Ave looks like with nothing but runners. I am in the middle acting like I won, but there are 12000 people ahead of me and six miles to go!