Cities like Pittsburgh must make it possible to return to the streets and shop without losing the safety of physical distancing, said Ricks. If only so many people are allowed into a store at one time, how can others line up outside? If restaurants operate at 25 percent capacity, where will expectant diners wait?

“It’s going to require us to reimagine our streets,” she said. “How much of our streets can we turn over?”

Many cities have already removed cars from streets to allow more people to walk and bike. They’ll need even more space if people are allowed to go to shops and restaurants again, said Brent Toderian, the former chief planner for Vancouver, Canada who now leads his own company, TODERIAN UrbanWORKS.

“All of it requires more space between buildings, more life between buildings,” he said. “If we try to do all that without inconveniencing the cars, we will fail.”