[This post has been updated.]

An annual marathon and half marathon that planners anticipate will draw more than 30,000 participants will close many D.C. streets Saturday. These closing for the Rock ‘n’ Roll Marathon have a history of creating citywide gridlock and Metrobus delays in the morning and early afternoon.

Click on map image for larger course map on Rock ‘n’ Roll Marathon Web site.

The marathon is set to begin at 7:45 7:30 a.m. Saturday, but some of the street closings will begin as early as midnight. All the affected streets should be reopened by 2 p.m.

Other major athletic events close streets each year, but the closings usually are concentrated around the Mall and along the Potomac River, and they’re often set for Sundays, when traffic is at a minimum.

The Rock ‘n’ Roll Marathon closes streets to Saturday traffic and sprawls across many residential neighborhoods that don’t normally experience such events. Capitol Hill, Adams Morgan, Columbia Heights, Southwest Waterfront and Anacostia are among the communities where streets will close.

Participants pass through all quadrants of the city. Major roadways affected include Constitution Avenue NW, Arlington Memorial Bridge, Rock Creek Parkway, Calvert Street NW, Columbia Road NW, Harvard Street NW, North Capitol Street, K Street NE, H Street NE, East Capitol Street, Minnesota Avenue SE, South Capitol Street and Maine Avenue SW. See a course map on the marathon Web site (pdf).

The Web site also has a list of all the streets to be closed (pdf).

D.C. police say they will are prepared to temporarily open some access points during the event when no runners are present. These are the intersections where traffic will occasionally be allowed across the route: Sixth and East Capitol streets NE, Eighth and East Capitol streets NE, Fourth and East Capitol streets NE, 10th and East Capitol streets NE, Eighth and H streets NE, 15th and North Carolina Avenue NE and 17th and C streets NE.

[Update: 11 a.m. Wednesday] Post reporter Patricia Sullivan notes that another traffic-disrupting event is scheduled for Saturday morning: the Four Courts Four Miler Race in Arlington County.

County police plan to close these streets.

  • Wilson Boulevard from Courthouse Road to North Rhodes Street from 6:30 to 11 a.m.
  • Wilson Boulevard from Courthouse Road to Route 110 from 8:45 to 11 a.m.
  • Northbound Route 110 from Interstate 395 to Interstate 66 from 8:45 to 11 a.m.

Street parking in the race area will be restricted so be on the lookout for “No Parking” signs, police said. They urged race participants to take Metro.

The race begins and ends on Wilson Boulevard near the Court House Metro station. The start time is 9 a.m. Saturday. See a course map here.

Metrorail will open at 5 a.m. — two hours early — on Saturday to help participants and spectators get into position for the marathon. The marathon start is on Constitution Avenue NW, just east of 14th Street. The transit authority advises participants to use the stations at Federal Triangle (Blue/Orange lines), Smithsonian (Blue/Orange lines) or Archives (Green/Yellow lines). The early opening will be paid for by the marathon sponsors.

Metrorail schedules
Metrorail is in the midst of a massive rebuilding program that will affect the rail schedules this weekend. The transit authority urges the marathon participants and spectators to use stations other than Franconia-Springfield or Greenbelt.

For many, the alternative to Franconia-Springfield will be the stations at Huntington or Van Dorn Street. Alternatives to Greenbelt include College Park and New Carrollton.

These are the Metrobus routes most likely to be disrupted by the marathon through early afternoon: 32, 34, 36, 38B, 42, 52, 54, 64, 70, 74, 80, 90, 92, 96, A42, A46, A48, B2, D4, D6, D8, G2, G8, H2, H4, L2, M6, N6, P6, S2, S4, U2, U6, V8, X2 and X8.

When the race begins, Metro said, buses on the affected routes north of Constitution Avenue NW will turn back at a point near a rail station, if possible. They will resume their regular routes into downtown D.C. as streets reopen.

South of Constitution Avenue, Metro said, there will be no regular service on the affected routes from the start of the race until the runners are clear of downtown. Service will be restored as streets reopen.

Other Southeast routes will return to regular service when the race ends.