Race Director John Mansoor admits he's gotten some unhappy feedback from folks who get stuck in traffic waiting for runners to pass by.

"There are a few folks who sometimes are not aware of the event. But most people are very understanding of this."

That's because Mansoor says the race pumps close to $8 million into the local economy.

"We fill up the hotel rooms from downtown all the way out to Folsom and a lot of people shop when they're here too, it being Christmas time."

More than 12,000 people will be running…either the whole 26.2 mile marathon or in four-person relays.

Fair Oaks Boulevard and other nearby roads will be closed much of Sunday morning to accommodate the race