The Philadelphia Inquirer has an article showing foot traffic at various locations around the city during the coronavirus shut down compared to average. As might be expected, foot traffic is down pretty much everywhere except grocery stores, where it is up slightly. This matches my personal observations. It doesn’t match the media accounts of crazy lines at grocery stores and big box stores in the suburbs. Maybe this is because in a dense walkable city, we have many small stores instead of a few large stores, and people tend to spread out their shopping over the entire day and week and to buy just a bag or two at a time that they can carry home. There are odd, sporadic shortages, but I have not observed any extreme shortages of basic goods.
The data supposedly come from Google. I tried to find out more about how, where and when Google is collecting this data, and came up short after 15 minutes or so of looking.
Now, I admit that clearly dense cities with a lot of social interaction have their down side right now. The big dense cities are also where the most international arrivals happen, and this factor along with density might be why they are the worst places to be right now. Hopefully they also have the largest medical facilities with the most experienced medical staff, but whatever we have is clearly not going to be enough to help everyone who needs help in the next month or so.