Some of the most elite runners from around the world — and about 47,000 other committed participants — are hereto run 26.2 miles as part of the Chicago Marathon.

The race begins in waves starting at 7:20 a.m. Sunday in Grant Park and follows a route through 29 neighborhoods. It is a flat, fast course considered one of the world’s six major marathons.

But it didn’t start out that way — nor was it called the Chicago Marathon. It began as the Mayor Daley Marathon, and the first race in 1977 wasn’t even 26.2 miles.

It has become more inclusive for a variety of people — including wheelchair racers — throughout the decades. It has been canceled only twice: in 1987 because of the lack of a sponsor and in 2020 because of the COVID-19 pandemic.

Here’s what to know if you plan to participate, cheer on a runner — or just want to avoid traffic jams on race day.

Date: Sunday, Oct. 13

TV: Live on NBC-5 from 7-11 a.m. Livestream available on nbcchicago.com and telemundochicago.com.

Radio: WSCR-AM 670

Start times

The start line is in Grant Park, which opens to runners at 5:30 a.m. Sunday, at the intersection of Columbus Drive and Monroe Street. Before entering Grant Park, there will be security and bag screening. All participants must use the clear plastic event-issued bag; no backpacks or luggage will be permitted.

Race organizers recommend participants arrive in their corrals about 20 minutes before the close of the corral. Wave 1 start corrals close at 7:20 a.m., with Wave 2 corrals following at 7:45 and Wave 3 at 8:10.

7:20 a.m.: Men’s wheelchair

7:21: Women’s wheelchair

7:23: Handcycle

7:30: Wave 1 (corrals A, B,C, D and E)

8: Wave 2 (corrals F, G, H and J)

8:35: Wave 3 (corrals K, L, M and N)

9:30: Spectator access to Grant Park begins

The course

Chicago has one of the flattest — and hence fastest — marathons in the world. Six world records have been set here, but many runners compete in this race to qualify for others, such as the Boston Marathon.

Runners start and finish in Grant Park but go as far north as Sheridan Road and as far south as 35th Street. Streets along the course will be closed for most of the morning and reopen on a rolling basis. (Note: The route is subject to change.)

Course records

2:00:35 (world record): Set in 2023 by Kelvin Kiptum of Kenya (men’s open division)

2:13:44: Set in 2023 by Sifan Hassan of Netherlands (women’s open division)

1:22:37: Set in 2023 by Marcel Hug of Switzerland (men’s wheelchair division)

1:38:44: Set in 2023 by Catherine Debrunner of Switzerland (women’s wheelchair division)

Time limit

The course is open for 6 hours, 30 minutes. Registrants must be capable of completing the full distance — start line to finish line — within this time requirement (about 15 minutes per mile). Participant times that exceed the event time requirement will not be recognized as official.

Parking

Runners and spectators can reserve a parking spot in advance through Millennium Garages, ParkWhiz or SpotHero. There will be no parking along the course.

CTA trains and buses

The CTA will add service on its Red, Blue, Brown and Green lines and earlier service on the Purple Line on race day. Some buses will be rerouted. See the CTA website for more information, including where to purchase passes in advance, race viewing areas near CTA stations and park-and-ride locations.

Metra

Metra will run extra trains in addition to its regularly scheduled Sunday train service on the Metra Electric, Milwaukee District North and Union Pacific Northwest and West lines. Unlimited rides Sunday are available for $7.

South Shore Line

The South Shore Line, which connects South Bend, Ind., with Chicago, will operate extra service on race day.

What Chicago residents should know

No-parking zones along the course will be enforced beginning at 1 a.m. Sunday, which means any vehicles in those areas will be ticketed and towed. Street closures along the route will occur between 7 a.m. and 4 p.m. Sunday. The roads in Grant Park will be closed longer. City streets will reopen promptly as the final runners pass through (at a 15-minute mile pace).

Road closures

Roads on the course close at 7 a.m. and will begin reopening around 10 a.m. after the final runners have passed through. In the Loop, plans are for the roads to reopen at 10 a.m. Lincoln Park roads are set to reopen around 12:30 p.m., Near West Side around 2:45 p.m., Pilsen around 3:15 p.m., Bronzeville around 4 p.m. and the entire course around 6 p.m. But as always, times are subject to change, so check first.

Roads that will remain open

Loop (bordered by Wells, Van Buren, Wabash and Lake): All streets in the Loop will be open to traffic by 9 a.m. on race day.

North of the Loop: Northbound and southbound lanes on Michigan Avenue (north of 11th Street) will remain open, including access to the Magnificent Mile. Clybourn Avenue, Lincoln Avenue (north of Sedgwick Street) and Clark Street (north of Diversey Parkway) will be open.

West of the Loop: Milwaukee Avenue, Halsted Street (north of Monroe Street), Ashland Avenue (north of Adams Street) and Damen Avenue (north of Adams).

South of the Loop: Damen Avenue (south of Jackson Boulevard), Ashland Avenue (south of Jackson), Archer Avenue (south of Cermak Road), Halsted Street (south of Cermak), Michigan Avenue (south of 35th Street) and Martin Luther King Drive will be open.

Grant Park

Roads inside Grant Park will close Thursday and most will reopen by Sunday evening. All streets will reopen by 6 a.m. Monday.

To avoid delays

Consider using Jean Baptiste Point DuSable Lake Shore Drive and the expressways — including the Dan Ryan (I-90/94), Kennedy (I-90/94), Eisenhower (I-290) and Stevenson (I-55) — instead of local roads.

What spectators should know

To avoid extra crowds, spectators aren’t allowed to escort runners to the start line or greet runners at the finish line. Organizers recommend spectators support runners from various spots on the course and meet up with runners after the race in designated areas within Grant Park.

Finish line

The closest spot to view runners at the finish line is the Bank of America Cheer Zone at Mile 26, Michigan Avenue and Roosevelt Road.

Reunite with a runner

The 27th Mile Post-Race Party and Runner Reunite area of Grant Park will open to spectators at 9:30 a.m. To access this area, spectators must pass through security and bag screening at Jackson Drive and Michigan Avenue or Ida B. Wells Drive and Michigan Avenue.

What participants should know

Race participants will meet at the start line in Grant Park.

Packet pickup

These must be claimed by each participant at the Health & Fitness Expo at McCormick Place, Lakeside Center on Thursday, Friday or Saturday. Bring photo identification to obtain a bib number, timing device, gear-check tag, participant shirt and bag. No one will be allowed to pick up these items on behalf of others. Items will not be available for pickup on race day.

Tracking

Runners can sign up to track live results or download the official mobile app. Results also will be available at chicagomarathon.com.

Security and safety

As in years past, only participants displaying their race bibs, event staff with proper credentials and ticketed guests will have access to the start and finish areas in Grant Park. Marathon participants are asked to use the transparent bags they receive from the prerace expo to expedite the security-screening process. Runners are required to register with a government-issued photo ID. The event website has information on the event alert system.

Sources: Bank of America Chicago Marathon, Tribune reporting and archives