LET ME BEGIN by saying I believe in vaccines. I am fully vaxxed and double boosted.

I believe in the value of wearing a quality, well-fitting mask in most indoor venues where I don’t know the people I am gathered with. I use an N95 in certain limited circumstances where I think the risk level is highest. Otherwise, I wear a KF94 because it is easier than an N95 to breathe with it on, and I have confidence it will perform well, as Korea imposes strict controls on mask production and approval. With very rare exception, I limit my restaurant dining to places where I can eat outdoors, or where the owner requires all customers to show proof of vaccination.

I am not an epidemiologist or medical professional. I believe in following the science, and the facts, as best we know them.

I also believe that the decision of Florida District Court Judge Mizelle to ban the federal transportation mask mandate was wrongly decided and inappropriately based on the judge’s personal ideology and a factual predicate that on its face is laughable. But I would not have chosen to appeal it.

I believe that lifting the mask mandate for public transportation is the right thing to do at this time. It would not have been the right decision a year ago, or even three months ago, and it may not be the right decision six months from now. But at a time when mask mandates across the nation have largely been lifted for indoor places, when effective vaccines are in ample supply and effective anti-viral medications are available as part of the treatment arsenal, keeping the mask mandate in place for public transit is a mistake. Here’s why.

Everything we have learned about this virus points to three key factors in the transmission of the COVID virus: duration of exposure, ventilation of venue, and proximity to an infected person. Those three factors – duration, ventilation, and proximity – matter a great deal and, for most people, one’s risk can be judged in large part by how those factors play out in specific circumstances. Let’s look at each as it relates to non-vehicular modes of transport.

Air travel presents the most compelling reason for enforcing mask wearing. One reason I do not support lifting the mask mandate on airplanes is that two of the three factors, duration and proximity, rate poorly. Ventilation on planes in flight is quite good, so that factor is covered. But by definition, air travel takes a while, and depending on your origin and destination, it is often a matter of several hours in the aircraft, and then in the airport, often in lines. Proximity is also an unavoidable air travel issue, as you have to accept being seated in fairly close quarters and with people who are strangers to you. So having a mask mandate for air travel continues to make sense to me. I could support lifting the air travel mask requirement if every airline simply required proof of vaccination for every traveler. That is clearly not on offer, so I do think it is problematic to lift the air travel mask mandate.

Transit is a different story. Transit performs well on the duration and ventilation factors. The typical bus or subway ride is a relatively brief excursion, often a matter of a few stops along a route. My guess is that the average transit rider spends as much time on a typical journey as they do shopping for groceries. (I am not talking here about travel on Amtrak, which typically mimics the duration issue presented by air travel, and which in my view should be treated accordingly).

Ventilation on transit systems is much better than most people realize. Ventilation is about introducing fresh air into a vehicle and filtering and recycling air within the compartment. That air exchange happens robustly on airlines. It also happens, with varying degrees of frequency, on subway cars and buses. Buses have an advantage: doors frequently open, and windows can be left open, so there is ample opportunity to introduce fresh air into the bus. Combined with on board HVAC systems, buses offer really good ventilation. Subway and train cars also have good ventilation, differing in degree according to type and age of equipment. New York subway cars exchange air 18 times each hour. The MBTA’s subway cars do the same roughly 10-18 times each hour, although the new Orange Line trains can achieve exchange rates of 40 times an hour. BART trains in San Francisco reach 50 times per hour.

Proximity is the one factor where transit, like air travel, poses concerns. Unlike airlines, transit agencies can mitigate this by improving capacity to prevent unreasonably crowded buses and subway cars. Running more buses and trains more frequently all day long will help achieve this. Changed commuting and journey patterns, driven partly by employers offering more flexible work hours, means that the severe pre-pandemic morning and evening rush hour peaks have reduced, flattened a bit, and therefore demand for service is more spread out throughout the day. Better transit frequencies means better access and safer trips for everyone.

Keeping a mask mandate on transit under the current circumstances would, in my view, unfairly and unreasonably stigmatize transit as something that is inherently less safe than many of the activities most people now undertake every day without a mask mandate in place. Attending events at sports venues, going to restaurants or bars, spending 30 minutes or more in a grocery store or retail environment – these routine activities are at least, if not more, risky if assessed by the duration, ventilation, and proximity factors.

We should not be sending the false message that transit is somehow so materially different that it should be avoided. There is nothing science or evidence-based about doing that. Stigmatizing transit does no one any good, and harms society overall as we seek to encourage more public transportation use as a way to reduce health-damaging carbon and particulate emissions, and as a way to promote access to opportunity and social cohesion. We can’t sacrifice those important societal goals.

Many of the routine activities of daily life (except grocery shopping) are discretionary acts, and oftentimes taking transit is not. Many people are transit dependent and must use the system to get to jobs or other important destinations. But most people are able to get fully vaccinated and wear a good mask if they choose, and the data has shown that taking these steps offers a great deal of protection. One-way masking is highly effective as a protective measure, especially when combined with vaccination. I respect the need to be mindful of those with medical conditions that make vaccines less efficacious. One solution is for state government to make paratransit options with enforced mask wearing available to people who simply cannot be in proximity to others.

There are many considerations to take into account, and as a society we should act in the pursuit of the best outcome, which may not also be the perfect outcome. We ought to balance the pros and cons of policies like enforced mask wearing informed by facts and experience. We should bring a large measure of humility to the task, in candid recognition that there may not be a perfect solution. Perfection is an elusive, unattainable goal in most endeavors, especially so in circumstances like this. We also need to commit to redirect our behavior quickly when circumstances change. The removal of the mask mandate won’t change how I behave. I will continue to keep current with vaccinations and will continue to wear my mask in indoor settings when it is required, or when it is clear that infections are rising.

The important societal goals I am concerned about – providing people with access to key destinations, reducing harmful vehicular emissions, rebuilding the urban small business economy, promoting social cohesion – cannot be fully realized in a long-term environment where people are misled into unreasonable fear of public transportation, unsupported by any evidence that it poses a larger risk than most other activities people routinely engage in every day. The vast majority of people have the tools to protect themselves. There are appropriate ways to care for the most vulnerable who cannot benefit from vaccines without doing permanent damage to the societal goals I have mentioned. Ultimately each of us needs to make the best informed decisions about our risk profile and risk tolerance as we engage our lives in full.

James Aloisi is a former Massachusetts secretary of transportation and a member of the TransitMatters Board.