Roads were closed Tuesday night from 20th to 8th streets and Arch to Walnut streets.
In a statement, a city spokesperson said: "The traffic closures were instituted purely as a precautionary measure in light of ongoing and expected demonstration activity."
Pedestrians were still able to walk around and all residents and essential employees were able to access the area if they showed ID.
The Office of Emergency Management lifted the closures at 4 a.m. Wednesday.
"Update: Philadelphia Police have reopened roads that were closed to vehicular traffic overnight within the Center City traffic reduction zone. Drive safely," Philadelphia OEM tweeted.