Many roads will be closed in D.C. and Arlington, Virginia, this weekend for the 51st annual Marine Corps Marathon. Most of the parking restrictions and street closures will be from early. The 51st Marine Corps Marathon takes over D.C. Why it matters: "The People's Marathon" is the nation's third-largest marathon without prize money, drawing thousands of. Several areas across Arlington County and D.C. will see road closures for the race.