The elite athletes and the amateurs will be pounding the pavement in the annual Bank of America Chicago Marathon. Final preparations are under way for the race.
Forty-five-thousand runners are registered. It is one of the largest marathons in the world and one of the most competitive.
This year could present a number of challenges, however, with numerous other events scheduled for downtown and warm weather in the forecast.
In addition to the 45,000 registered runners, the marathon course is lined with an estimated million or so fans. On marathon Sunday in Chicago, it is all about the runners. The job of making sure it all comes together falls to race director Carey Pinkowski.
"These are the finest athletes we've had in the history of the race," said Pinkowski.
Pinkowski has directed the race for the last 21 years and has seen it grow from a few thousand runners to a huge international event with world wide television coverage.
Jim "Skinny" Sheahan is running his 26th Chicago marathon this year. He also used to work in Mayor Daley's administration.
"Everybody is involved in this," Sheahan said.
Recognizing the mayor's support, and knowing he's not running for reelection, race organizers invited him to run the race instead. And while that's unlikely, Bank of America, sponsor of the race also gave him a check for half a million dollars for his Chicago Youth Fitness Initiative.
The mayor has become a big supporter of the race.
"This shows the beauty of Chicago," Daley said.
Race organizers are expecting great weather to show off the city to visitors, but the forecast for warmer temperatures could cause problems for some runners. They say they learned a lot after having to stop the race early because of warm weather and a lack of water in 2007.
"Since 2007, we've increased the water," said OEMC's Jose Santiago.
"The event alert system's been very important," Pinkowski said.
The marathon starts in Grant Park, heads north to Addison, west to Damen and south to 35th Street.
For a complete list of street closings and parking bans you can check out the City of Chicago's website.