This Tool Might Help Calculate the Risks of Outdoor Dining

“This is not the year to be going out and about,” Palo Alto-based infectious-disease doctor Dr. Krutika Kuppalli told the SF Chronicle last month. “I understand that people are getting cabin fever, but the first recommendation I’m going to make is people stay as close to home as possible.” But for many folks, the sense of isolation they’ve experienced during the pandemic is almost as strong as the fear of infection. Now there’s a new tool from the Georgia Institute of Technology that can help you calculate your risk of infection during a sit-down, outdoor meal.

With indoor dining on hold for an indefinite period of time, restaurant patrons must rely on takeout, delivery, and outdoor seating (if a spot has it) for their favorite dishes. Delivery and takeout are relatively low-risk propositions, assuming that you and those around you maintain proper social distancing and face covering protocols.

That risk increases when you sit down for a meal, even outside — speaking with the Chron in June, Dr. George Rutherford, head of the division of infectious disease and epidemiology at UCSF, ranked “going out for dinner and a drink” as one of the “highest risk” activities one can engage in, as in a sit-down dining setting, you can expect more sustained contact with potentially infected folks. “If you want to go to a restaurant, I’d either go very early or late, and miss the crowd,” Rutherford says.

The volume of an area is also a factor. If you’re dining al fresco on a busy, loud street and have to raise your voice to be heard, the risk rises yet again. That’s because, as the Chron reported in June, loud talking produces “significantly more exhalations of viral droplets than normal activity and thus spread[s] the virus.” That argument is one of the reasons the state ordered bars that don’t serve food to cease operations last month, saying then that “louder environments and the cacophony of conversation that are typical in bar settings, also require raised voices and greater projection of oral emitted viral droplets.”

So, we know all this, but, still, life is a set of risks, and “sitting down for a meal gives people a sense of normalcy in an abnormal world,” Cassandra Carter, a server at Cole Valley brunch-and-dinner standby Zazie, says. That’s why Georgia Tech created an interactive map to allow folks to determine just how much of a risk they’re taking while enjoying a sit-down meal, or at any other sort of gathering, professor Clio Maria Andris tells NBC Bay Area.

Speaking with the Chron, Georgia Tech prof Joshua Weitz says that their map uses data from the Atlantic’s COVID Tracking Project (tagline: “The public deserves the most complete data available about COVID-19 in the US. No official source is providing it, so we are.”) and 2019 census data to calculate the chances that you’ll be in a gathering that also contains a person infected with coronavirus. (The map can’t possibly calculate your chances of infection or even exposure — just the chances that someone else where you are might have the virus.)

Some experts say that the information on the map might mislead people into a false sense of security — for example, Stanford University infectious disease expert Robert Siegel tells the Chron that “it’s more of an explanatory thing than a model for behavior,” and that it should not be used as the only way to determine if and when you should go out. It is, however, better than nothing.

Here’s how to give it a spin:

1. Go to the map site here.
2. Scroll down the left sidebar to choose the “event size” based on the outdoor seating capacity of the place you’re thinking about visiting. 10 is the minimum, so for places with just a few tables on the sidewalk, that should be fine. The next choice is 25, which makes more sense for places with small patios or shared spaces platforms.
3. Use the zoom in tool (the little plus on the upper left) to see the Bay Area.
4. Roll your mouse over each county to see the likelihood that a person with COVID-19 will be in that group.

Based on the map, as of publication time, San Franciscans in a 25-person group have a 37 percent chance of being with a person with coronavirus. That probability drops to 17 percent when the group shrinks to 10.

Obviously, there are some flaws in the data — just looking at the map for Marin County, one has a 50 percent chance of being in a 25-person group with a person with COVID-19. But those numbers are skewed by the massive outbreak at San Quentin Prison, at which (as of Monday) 2,231 inmates and 261 staff members have been infected.

Despite that, Weitz says that the map can be useful in helping people get their heads around how safe it might be to engage in various activities. “We want people to be informed about the risk,” Weitz tells the Chron. “That it’s real, it’s elevated, and many people may be asymptomatic.”