Update: 2:30 p.m.
All streets closed for the marathon have reopened except for East Capital St. NE in front of RFK Stadium, according to D.C. Police.
The Rock n’ Roll USA Marathon and an associated half marathon, which rolled out through the city’s four quadrants early Saturday, prompted street closures that have led to some traffic tie-ups on some of the District thoroughfares.
The Metropolitan Police Department advises that drivers should avoid these streets through 4 p.m., but rolling closures have begun as the tail of the races passes certain spots.
Carly Schnitzer, 18-year-old volunteer, was attached to her megaphone, directing runners at the corner of Constitution Avenue and 13thStreet NE, a mile from half-marathon finish.
"Everyone must turn down this street right here," Schnitzer said. "Full marathoners will merge to the right side of the street. If you are running the half marathon, you will be merging to the left side of the street."
The race began at 8 a.m., with street closures expected through 2:30 p.m., according to the District Department of Transportation.
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— Del Quentin Wilber and Michael D. Bolden