Did Subway Riders or Motorists Do More To Spread COVID-19 in New York City?

Transit wonks are debating which mode of transportation was most responsible for the country's worst COVID-19 outbreak.


Is the New York City subway system responsible for seeding the nation's worst COVID-19 outbreak? Or are the Big Apple's motorists to blame? The answer has major implications for our immediate response to the COVID-19 crisis, and the role cities will play in a post-pandemic America.

The debate started last week when Massachusetts Institute of Technology economist Jeffery Harris published a controversial working paper claiming that the nation's largest rail transit network was the major vector for spreading novel coronavirus in New York City, where it has killed over 10,000 people.

"New York City's multitentacled subway system was a major disseminator—if not the principal transmission vehicle –of coronavirus infection during the initial takeoff of the massive epidemic," wrote Harris in his paper, which was originally published on April 13.

Harris, in his initial paper, cites two pieces of evidence to make his point. The first is a correlation between a fall in subway ridership and the falling rate of new, reported COVID-19 cases. The number of daily turnstile entries fell from nearly 6 million to just over 500,000 by late March, his paper shows, which corresponded with a dropoff in new infections. New cases of the virus, Harris notes, fell most in areas of the city that saw the biggest decline in transit ridership.

"The near shutoff of subway ridership in Manhattan—down by over 90 percent at the end of March—correlates strongly with the substantial increase in the doubling time of new cases in this borough," writes Harris. Boroughs with a less dramatic fall in ridership saw shorter doubling times for new cases. ("Doubling time" is the period of time required for an observed phenomenon to double in number; in the case of a pandemic, the longer the doubling time, the better.)

Harris' first draft also includes a map of new COVID-19 cases broken down by ZIP code, which he suggests shows that one subway line stretching from Queens to Manhattan correlated with disease hotspots in the city.

In his original draft, Harris caveats all of this by saying correlation does not equal causation. But on April 19, he released an updated paper which pointed to the high death rate among the city's transit workers—79 of whom have reportedly died of COVID-19—as the smoking gun proving his case.

"How ironic it is that [the] unfathomable tragedy of these frontline workers turns out to be the clincher that transports us from correlation to causation," he said.

This paper and its conclusions have fueled calls by some officials to shut down New York's mass transit system, which carries nearly half of the country's transit riders, to help stem the spread of the virus. On Saturday, the New York Post reported that three New York City councilmembers sent a letter to Gov. Andrew Cuomo (D) urging him to temporarily close the subway and suspend bus service.

"We believe that the New York City transit system is a primary contributor to the spread of COVID-19, and we recommend a temporary closure of the system for at least one week for deep cleaning of trains, buses, and stations," these councilmembers wrote. They, like Harris, suggested that the city subsidize rideshare or cab rides for essential workers. So far, Cuomo has resisted these calls.

At the same time, a number of voices are pushing back on Harris' conclusions, and even suggesting the counterintuitive idea that motorists, not transit riders, are the ones most responsible for spreading COVID-19 throughout the city.

In an article over at Market Urbanism, Salim Furth, a researcher at George Mason University's Mercatus Center, pokes holes in Harris's case. While cratering subway ridership is correlated with a slowing rate of infection, says Furth, so are a lot of other activities.

"People take the subway, not for the heck of it, but to get places. When those destinations are places they no longer want to go or are no longer allowed to go" they ride less, Furth tells Reason. Thus, it becomes difficult to disentangle the effects of falling subway ridership from all the other social distancing measures that were happening simultaneously. Falling restaurant visits and declining use of bike-share also correlate with a declining infection rate, he says. But that correlation doesn't tell us anything specific about the role restaurants and bike-sharing played in spreading COVID-19 around New York.

While boroughs that saw a smaller percentage decline in transit ridership also saw a smaller decline in the rate of new cases, Furth says these same boroughs had lower numbers of transit riders to begin with.

"If subways (or ferries) are the primary vector, why is Staten Island, with a 67 percent automobile commute share, just as susceptible to COVID-19 case growth as the rest of the city?" Furth writes. "The change in transit usage is plausibly consistent with Harris' hypothesis; the level of transit usage is inconsistent with it."

The fact that transit workers have a higher death rate than transit riders could point to some sort of institutional spread within New York's transit agency, Furth argues. It is not proof that subway cars themselves are the primary disease vector.

The Metropolitan Transportation Authority, which runs bus and train service in New York City, also prevented its employees from wearing masks throughout early March.

In his response to Harris, Furth compares U.S. Census Bureau data on the share of people commuting via car to the number of new COVID-19 cases broken down by ZIP code. He found that rates of car travel are highly correlated with the number of new infections. Outer boroughs, where rates of car commuting are highest, are also showing the highest rates of COVID-19 infections.

Furth offers two theories for why motorists, not transit riders, might have been more likely to spread coronavirus. "Cars may give you a false sense of security," he says, suggesting drivers could have reduced their travel around town less than transit riders. "Somebody who only has the subway to get around may be only relying on delivery, only going to the corner store, not leaving their block for commerce," Furth says.

In addition, he says transit riders could be interacting with a more tightly-knit network of people; others who take the same subway line or frequent businesses near the same transit stops, for instance. That would reduce the number of new people they run the risk of infecting. Auto travelers, by comparison, could have a more random network of interpersonal interactions, helping them to spread infections farther and faster.

This is not just an academic debate. In the short term, knowing which mode of transportation is more likely to contribute to the spread of COVID-19 would help guide immediate policies for combating the virus.

If Harris is correct, then it would make more sense to shut down transit for deep cleaning or subsidize Lyft and Uber rides. But if cars are helping transport the virus, then raising bridge tolls or closing some bridges and highways in New York altogether might be the smarter move.

Getting this response wrong would mean actively encouraging the most dangerous modes of travel. Urbanites are also debating the longer-term impacts of the coronavirus pandemic on denser cities. Reason just published a video exploring this very topic.

Finding solid answers to these questions will determine how tens of millions of Americans get around each day, where they live, what kinds of developments their governments encourage and restrict, and how their tax dollars are spent.

NEXT: Education Won’t Be the Same After the Pandemic Passes

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  1. We obviously need to reduce population density by sending everyone to the countryside to work in the rice fields.
    Pol Pot = Best Pot

    1. Pepper Potts.

      1. John Jonah Jameson Jr.

        What are we doing.

      2. Annie Potts?

  2. Getting this response wrong would mean actively encouraging the most dangerous modes of travel.

    Then unless you want people to die, there’s no choice. All convenient modes of travel remaining in NYC must be eliminated.

    1. Not paranoid enough!

      We need to shut down all travel into and out of NYC. Then we need to build a wall, a beautiful glorious wall, and shoot everyone who tries to leave. It’s the only way to stop the zombie horde!

      1. Snake Plissken hardest hit.

        1. I thought he was dead.

      2. Funny

        But still, it is certainly intuitively obvious that it is impossible to maintain 6 ft social distancing in NY subways, busses, or even sidewalks during busy times.

        Certainly, if social distancing works, then the inability to maintain social distancing is a problem. Seems clear that the inability to maintain social distancing and a high concentration of European travel would largely explain the concentration of Wuhan Flu in the NYC metro area.

    2. All convenient modes of travel remaining in NYC must be eliminated.


  3. If everyone on a train was going to the same place you would only need one entrance and one exit. By their very nature they are about forcing people with a multitude of destinations to sit directly beside people with a multitude of origins.

  4. It seems like you might do some comparative studies – how many motorists got sick in Wyoming compared to the number of subway riders in Wyoming? That might provide a clue as to which way the argument leans.

    1. subway riders in Wyoming

      Nice band name.

      1. Did they inspire the song ‘Riders on the storm’?

  5. In the short term, knowing which mode of transportation is more likely to contribute to the spread of COVID-19 would help guide immediate policies for combating the virus.

    “Since we don’t know, our guided policy is to suspend them both. After all, it might help save just one life.”

    1. How will women get to the abortion centers to end ‘just one life’ ?

  6. With the promise that shutting down the subways would allow ‘deep cleaning’. There is an overused canard, the deep cleaning meme.
    The virus does not stick around all that long. And if it is on a surface, then no big deal, just watch where you put your hands next (hint, not to your face).
    A perfectly sterile subway car stops being deeply cleaned with the first passenger, and is utterly filthy with germs in minutes.
    There is no getting around population density problem. 67,000 people per sq mile in manhattan, or about 400sq feet per person. In my midwestern city of 2 million, population density less than 2000 per mile, or 14,000 sq feet per person. Which maybe explains why with a family of 4 and only one acre I’m feeling a bit cramped.

    1. But think of THE JOBS!!

    2. Actually, they’ve failed to scientifically prove smear transfer at all. That you can get covid-19 off surfaces is unproven conjecture.

      (“Contrary to original assumptions, however, the WHO determined at the end of March that there is no evidence of aerosol dispersal of the virus. A leading German virologist also found no aerosol and no smear infections in a pilot study.” , #14 from the Overview. Includes a link to the paper, but the paper is behind a paywall).

      1. WHO determined at the end of March that there is no evidence of aerosol dispersal of the virus. A leading German virologist also found no aerosol and no smear infections in a pilot study

        Thus it only spreads by direct contact with bats! Proven.

    3. “There is no getting around population density problem. 67,000 people per sq mile in manhattan, or about 400sq feet per person.”

      Social distancing says we should stay at least 6 feet apart. A 6 foot radius circle has an area of 113 square feet. More than 1/4th of the available per person space in New York.

    4. It’s interesting to note how different Tokyo’s experience with the Coronavirus has been compared to NYC. Tokyo is larger, but its population is not as dense. Japanese citizens have been in the habit of wearing masks for many years, especially in urban areas. Tokyo’s subway system is pristine compared to NYC and it carries more passengers each day. To be fair, the NYC system runs 24 hours a day and covers more miles. Tokyo’s system shuts down each night and is thoroughly cleaned. There are surely many other factors in play, such as health conditions, obesity, diabetes, high blood pressure. The residents of Tokyo are probably scoring better than New York city residents on some of those important issues. Most of the deaths – world wide – from COVID-19 have been people with compromised immune systems, high blood pressure, heart disease, etc. Here’s a quote from an article on the NIH website: “The prevalence of overweight and obesity is higher in the US than in Japan, as is the prevalence of heart disease, diabetes, arthritis, and functioning problems. Education level and marital status are predictors of overweight for older Americans but not for older Japanese people.”

  7. Well it is obvious on the face of it that a person riding alone on a car will transmit just as much of anything as some poor schmuck jammed into a subway car last used as a urinal.
    Well, at least it is obvious in NY to the totally unbiased politicians elected by transit workers unions.

  8. Dont need to shut it down, just clean and sanitize the cars, platforms, everything. The entire system was filthy and disgusting before and now it is 1 million times worse with feces and garbage and rats everywhere. Get the national guard in there to do it. Someone, anyone. Its a nitemare.

    1. Uhh, you ever been on the subway

      Yeah, lots of people use it, it gets dirty, it could be better

      little to do with the virus

    2. You know who else was a big fan of exterminating every filthy, nasty, dirty living thing off of a train? I mean, sure, New Yorkers are filthy nasty disgusting creatures, but maybe instead of sterilization, just install showers on the trains. Oh, wait, shit.

      1. I LIKE IT …. oh wait, you like showers with WATER … never mind.


    3. When you have people breathing in each others faces, cleaning and sanitizing isn’t going to help much. And getting more people out and about NYC to clean is likely to do more harm than good.

  9. Paper does not pass teh laugh test

    If the subway workers had gone on strike and the virus cases dropped, and all other things remained the same, OK, that would make sense

    This, this is just dumb.

    Restaurants closed
    businesses closed
    people stay indoors

    I mean, how much do you have to hate mass transit to think this up

    1. How much do you have to hate cars to think they could be the spreading vector as opposed to crowded sweaty subway cars filled with bums and gropers?

    2. The paper may not prove it, but I don’t see how the subways couldn’t be a major location for people picking up infections. It’s not a criticism of subways as such. Just how things work when you cram a lot of people in a small space. I’m sure people pick up loads of colds and flu on the subway every year.

  10. I see Staten Island has indeed passed up Queens for second in the cases per population metric, which is indeed interesting as it is the borough that is most suburban in character. It is worth noting that SI has far and away the lowest population of the boroughs, about 1/3 of the next closest. So every positive case has a much bigger impact on their relative cases than the other boroughs. Of course the whole idea of looking at cases per population is to take that out of the equation, and it should, but it’s something to consider. I have also seen it said that anecdotally, a lot of cops (and I would guess other emergency personnel) live on SI, which would seem to give some above average chances for exposure to infected populations which then come home to their families.

  11. Don’t forget the bus riders? What are they, chopped liver?

  12. The headline asks a really stupid question.

  13. Talking about spreading- what is the deal with slaughterhouses? I noticed that Brown County, WI has had some major jumps in cases recently, and apparently most of them are coming from one or two meat packing plants. And of course we have heard about Smithfield, et al. I have a hard time believe that close working conditions alone explains it. I wonder if it is because of a generally moist and refrigerated environment? Still, most of those people are gloved (and maybe masked?) anyway.

    1. …generally moist and refrigerated environment..
      Nailed it.

    2. Well, the fact that they are essential businesses and people are actually going to work there would be a factor too.

      1. Wisconsin has a ton of manufacturing, and pretty all of it is considered essential and continues to operate. I assume most midwestern states are similar. But meat packing seems to be the only one having outbreaks like these in individual plants.

        1. Hmmm, I wonder if it has anything to do with the persistent habit in the meat packing industry to employee illegal aliens? you know, people who live in high concentrations, avoid medical care, … no?

          1. Seems to have a significant impact. There seems to be a lot of transmission outside of the workplace.

  14. So, let’s see one mode of transportation is mostly isolated and other one involves being tightly packed with strangers. Yea, we’ll never get to the bottom of that one. I’d encourage Salim Furth to actually ride the NYC Subway and then rewrite his paper.

  15. //This is not just an academic debate. In the short term, knowing which mode of transportation is more likely to contribute to the spread of COVID-19 would help guide immediate policies for combating the virus.//

    Easy. Transport the immune in cattle cars, to and from the gulags. Anything short of that present an unacceptable danger to the public. Ultimately, we suspect leaving people in the gulags will reduce the rate of inadvertent infection to 0%, due to the reduction in back-and-forth transportation. It will also save money. Issuing one-way tickets, therefore, is the most sensible method of protecting the vulnerable.

    On the bright side, those among the most at risk that do not perish can look forward to joining their friends in the camps. There will be plenty of allowances granted for outdoor exploration and activities.

    1. Oh, fuck you, ya retarded idiot! You’d just as soon go back in history where they transferred people to camps to be systemically murdered! You know what, Geraje Guzba? You’d do the late Boston School Committeewomen, Louise Day Hicks and Pixie Palledino, as well as the late Boston City Councilor, James Kelly, of Southie mighty proud. Thanks a bunch, you retard!

      1. I can’t tell if you’re trolling me, or supporting me, or what the fuck that was.

        1. Two broken sarc detectors.

          1. Are sarc-detector fix-it shops an “essential service?”

            Inquiring minds want to know.

  16. This article lacks common sense.

    The NYC subway system was an all day super-spreader event for a month running.

    That’s why NYC has done so much worse than LA.

    1. But, on the up side, they are probably getting pretty close to herd immunity.

  17. I don’t know about NYC, but I do know that there are enough assholes here in the Bay State who are flouting the rules about social distancing and wearing masks when they go out in public, without a care in the world about the fact that they’re screwing everybody else over and prolonging this mess. Those spoiled millennials and their pals are a bunch of nasty, arrogant, willfully stupid people who don’t care if they end up killing or permanently sickening other people, especially more vulnerable ones. The parents who raised these spoiled, selfish brats are responsible. I don’t give a shit if they take themselves down, but the fact that these spoiled brats take others with them is the most disgusting of all.

    1. Yes, at least 10 young people should take a vow of poverty so that each 85 year old with heart disease and emphysema can spend an extra few months in the home.

    2. without a care in the world about the fact that they’re screwing everybody else over and prolonging this mess.

      You do realize that the stated intent of the social distancing and mask wearing is exactly to prolong this mess? If we wanted this mess to be over as soon as possible, we should have done nothing once it was clear that containment would not work (which I think was about two and a half months ago).

  18. which he suggests shows that one subway line stretching from Queens to Manhattan correlated with disease hotspots in the city.

    Except that the actual map of disease hotspots around the city that he shows doesn’t show that at all. He just connected one hotspot in midtown Manhattan with another more extensive hotspot in Queens.

    The hotspot in Queens is actually perfectly aligned with La Guardia Airport going south on I278 and then east a bit on I495. Which is more like the commuting pattern of airport workers and passengers from Long Island

    The hotspot in midtown Manhattan is at the exact point where the Lincoln tunnel exits/enters NYC and a couple of blocks from both Grand Central Station and Penn Station. And golly – Times Square. IOW while those city residents who work at those locations took the infection home with them by subway, they almost certainly caught the infection at midtown Manhattan.

    1. Looking at those zip codes that are the hotspots – in isolation, it seems to me more likely that Uber/Lyft/taxi drivers were the initial vector. Getting infected by inbound international air passengers – passing it on to either tourists or suburban commuters/travelers and the places where they get a coffee/snack to be well-situated to get their next fare from the Uber/Lyft/taxi crowd.

      That is also what makes sense when NYC is seen as the epicenter for the whole East Coast. It isn’t subway riders who spread things outward from NYC. It was the the Amtrak/commuting crowd, tourists who went to NYC for a show and returned home, and the initial passengers from Europe who flew in to NY airports.

      1. If you look at the infection spread in Connecticut, it’s up and out from NYC with a small smattering in other places.

  19. Only a progressive loon would debate this. It’s obvious what the answer is.

    1. Drivers too close for comfort giving each other the finger?

  20. Shorter Article:

    Experts Have No Clue. But They Still Have An Opinion, Which You Peon Are Not Free To Disagree With. Cause They’re Experts.

  21. The problem with this whole approach is that it ignores that transportation is just a means to go from here to there. Subways no doubt are greater vectors for infection because many people are packed tight together, which they are not in cars.

    But people in cars go somewhere, mingle with crowds, and then come back. If you live 40 miles out in NJ or CT, and commute to NYC every day, and you go through the bus or train station on the way in every morning and mingle with hundreds of people, and then you walk through crowded streets to get to work, and then go to restaurants and bars for lunch or after work where you mingle with more crowds, and then go home, again through a crowded bus or train station, you have plenty of opportunity to get infected, and you can spread the disease driving home.

  22. My hope is that there will be a renewed interest in UV-c light disinfectant systems. The technology is used in hospital operating rooms and in water and air purification systems. In China some public buses are now being blasted with the lights when not in service. No doubt trains, subways, elevators, and taxis could be retrofitted and reduce most of the virus transmission that occurs on mass transit (34% on average and likely much higher in New York City). Reducing the risk of COVID and also the more common (and often deadly) influenza would be a far better gift to workers and the economy than the guaranteed income suggested by AOC.

    Unlike a hospital setting, transportation systems do not have to be sterilized 100% to be effective. The U.S. can become a leader in robotic sanitation systems and make dense urban areas reasonably safe for business and tourists.

    There is a lot of money to be made in doing the right thing.

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  24. This is just common sense. Lots of people pressed up against each other in little metal boxes, (trains, buses, and subways), of course helped spread the virus because close quarter contacts is how viruses spread. We have a thousand years of history to back this up. I do not get the issue here? I mean it is not like they are going to be closed forever. When the virus is under control and if they can develop a vaccine, things will go back to normal.

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