CHICAGO (CBS) — More than a million spectators will line Chicago streets Sunday to watch the 41st annual Bank of America Chicago Marathon. That means lots of road closures throughout the city and motorists looking for different routes to get around.

According to the city’s Office of Emergency Management and Communication, people traveling through the downtown area and throughout the various neighborhoods “should allow for extra time, expect delays or consider alternative routes to avoid the impact of the race.”

Beginning Thursday, Columbus Drive closures start with Roosevelt Road to Congress Parkway. Starting Friday, Congress Parkway to Monroe Street will be closed October 5 at 4:00 a.m. On Saturday, the Columbus Drive closure will extend to Randolph Street at 6:00 a.m. and Monroe Street from Michigan Avenue to Lake Shore Drive will be closed at noon.

Also, street closures along the route will start around 7:00 a.m. and expected to be reopened by 4:30 p.m. “or when it is deemed safe to do so,” according to an OEMC news release.

Visit this site for a list of the street closures and the race day routes.

More than 40,000 runners are expected to participate in 26.2 mile run.

Click here to see a map of the Chicago Marathon course.