Imagine: a severe pandemic races through the United States, hitting cities like New York hard. Public transit is partially blamed for the spread, given that transit works best by squeezing in a lot of people in tight places to move them efficiently.

What happens next, as the virus dissipates? After a few years dealing with panic and fear of being too close to others, how will urban residents react?

In response, residents could start to abandon cities and the public transit they depend on. Americans might choose to move out of high-cost, dense transit-dependent urban areas to emerging lower-cost, western cities, built around the automobile and single-family homes. They might abandon transit forever.

The result could be catastrophic, an environmental wasteland dominated by suburban sprawl, crushing traffic, and choking pollution, with little open space or agricultural land preserved. Those left behind in cities to ride transit will predominantly be lower-income individuals who can’t afford a car or single family home – too often people of color. This dynamic will only worsen racial disparities, and transit service, already underfunded, will worsen.

But this harsh reality is actually not the future — it’s what already happened in our past. Specifically, after the 1918-1920 Spanish Flu, urban residents abandoned American cities, particularly in the East Coast, lured to the cheap housing and car culture of places like Los Angeles. Developers sold the West Coast “car suburb” to newcomers as offering an escape from disease-ridden cities. The result was the environmental degradation and ongoing racial residential segregation we see today.

To be sure, since Spanish Flu times, trends on transit have reversed to some extent. Urban rail transit launched a comeback starting in the 1960s, and cities have since been revitalized with strong demand for housing. Voters have increasingly taxed themselves to build more and better transit, particularly with local sales tax measures.

And in the Spanish Flu era, the automobile was new and exciting, but the limits of the technology were not yet widely understood. Consumers only saw the upsides of driving, not the downsides of increased traffic, pollution, transportation costs, suburban isolation and lost open space. Since that time, we’ve learned many of those lessons and implemented new environmental policies to counteract the pollution and sprawl.

But public transit is indeed in serious danger. Fear is powerful, and those with means will choose to drive or work from home instead of taking on the risk of getting the virus from transit. Those with no other option, such as people with low-incomes, service jobs requiring in-person work, or disabilities, will have no other choice, exacerbating social inequities.

The result will be a downward spiral: as ridership plummets, budgets take a hit, transit service is cut back, and the systems overall can become unappealing to lure “choice” riders back who could otherwise drive.

This future in many ways is already here, in the initial months of COVID sheltering. As Janette Sadik-Khan and Seth Solomonow noted recently in The Atlantic, ridership on bus and rail systems has already dropped from pre-pandemic levels by:

• 74 percent in New York
• 79 percent in Washington, D.C.
• 83 percent in Boston
• 87 percent in the Bay Area

We all have a stake in making sure this outcome isn’t permanent. Transit is essential for cities, as our economic and cultural engines, to function well. We also need transit to reduce driving miles and pollution and reduce pressure to sprawl. And transit can address equity concerns, by providing mobility for those who can’t afford a vehicle.

So how do we save public transit post-Coronavirus and not repeat the mistakes of the past?

First, transit officials and advocates need to address the public’s fear. The evidence on viral spread via transit is mixed at best. On its face, we’ve seen outbreaks in places with heavy public transit use, like in New York City, so the public and some scientists have superficially connected transit ridership with disease spread.

But recent studies in Paris and Austria showed no spread from transit. And looking at the geography, it’s hard to see a connection between COVID and transit:

• Hong Kong with heavy transit use has recorded one-tenth the number of cases as Kansas
• In New York, car-heavy Staten Island has had higher infection rates than transit-dependent Manhattan
• Cities in South Korea, Taiwan and Japan have had little infection compared to suburban parts of the US or Italy, where outskirts of Milan were hit harder than the city itself

In general, spread seems to be more acute in places like nursing homes and prisons and among families living together, not via transit.

Second, transit officials should point to and replicate success stories. Taipei in Taiwan provides perhaps the gold standard. Taiwan officials require mandatory mask wearing on trasit. They use noninvasive handheld or infrared thermometers to screen all riders. They test, trace and quarantine, and they clean the systems well. Transit officials also adjust service to limit crowding. All of these steps require resources in times of budget crunches, so we’ll need financial support for transit, for both environmental and equity reasons.

Third, officials can highlight the miserable alternative to supporting transit. Without transit, we would see significantly more traffic congestion, including traffic deaths (averaging about 37,000 in the US per year). We’d also see more pollution, imperiling our air quality, public health, equity, and climate goals.

Fourth, we need to boost non-automobile alternatives to transit. These options include “active” transportation, timely with e-bike sales skyrocketing and the proliferation of e-scooters. Cities can also explore employing more shuttles and vans instead of mass transit. And they can set aside street infrastructure for all of these uses, as well as offering rebates and other incentives to encourage e-bike and e-scooter purchases, to replicate success we’ve seen with zero-emission passenger vehicles.

And there looms one major, yet controversial idea to consider for the long term: replacing all rail transit with far-cheaper and more efficient automated, electric bus-rapid transit lines (ART) on the dedicated lanes of former rail tracks. This transition would harness new technology in self-driving software and improvements in batteries to save transit agencies orders of magnitude in costs for operations and maintenance compared to rail. And with rows of connected buses, ART can replicate the capacity and electric propulsion of rail at a fraction of the time to build and money to operate — timely for squeezed transit agency budgets. Now might be the time for transit agencies to study these conversions.

In the future, public transit post-COVID doesn’t necessarily have to replicate the past. But unless we act now to bolster public transit and its sustainable alternatives, we may indeed find ourselves moving backwards, in more ways than one.