From the city website:

PITTSBURGH, PA (March 30, 2020) Neighborhood street sweeping by the City of Pittsburgh Department of Public Works, which was due to begin Wednesday, April 1, is being postponed due to the COVID-19 virus.

Some street cleaning, as well as catch basin cleaning, will still be performed to help with protections against weather-related events. But with residents staying home and parking enforcement being suspended to help fight against the pandemic, the normal April 1 start to street sweeping season is being postponed until further notice.