Route 1 is closed in both directions from Slater’s Lane to First Street in Alexandria due to two fallen electrical poles in the road.
Earlier delays because of a train malfunction are clear.
Trains were stopped at Fort Totten.
Crews are waiting for asphalt to cool and should be finished working on southbound lanes by midday Thursday.
Authorities reopened the highway following the 6:10 a.m. accident, just before Route 97, also known as Georgia Avenue.
Emergency pavement repairs will close lanes, even during peak commuting times, through the week, Maryland officials say.
Metro Transit Police pull a man back onto the station platform just seconds before a Red Line train would have struck him.
Multiple vehicles were involved in the crash.