This Saturday, more than 20,000 runners are expected to run in the United Airlines Rock ‘n’ Roll Washington D.C. Half Marathon, which starts in downtown D.C. along the National Mall and snakes around the city, ending near RFK Stadium.

Most road closures and detours will last from 7 a.m. to noon. However, some closures will begin as early as 3 a.m. and continue past 1:30 p.m. Streets will reopen on a rolling basis as the last runners pass through each area and the race material is removed.

D.C. Police will be enforcing no-parking blocks, including large stretches of H Street NE; North Capitol Street; Harvard Street NW; Columbia Rd. NW; and more. Locals are encouraged to move their cars from those blocks or risk getting towed.

The organizers posted a full list of closures and no parking zones online.

Signage will be posted along the 13-mile route, listing “No Park – Tow Away Zones” and detours.

Some sections of roads downtown — including 9th, 10th, 12th, and 14th Streets NW — will be shut down to north-south traffic from 5:30 a.m. to noon. In addition to some Metrobus delays, the D.C. Streetcar will delay service until 3 p.m. during the half marathon, as the race includes H Street from 4th to 13th streets. The event’s organizers urge local residents and businesses to plan ahead.

For maps of the routes and closure times, see below.