Have you ever noticed that many surfaces in public places are made of metal? That is an infection control measure, as some metals have microbicidal properties. In addition, the air systems are designed to minimize risk of disease transmission. Infection control is a huge public health issue, yet the majority of people hardly know a thing about it. The major source of infection in public subways would be from direct exposure to a sick person, not from the air or surfaces. And most people do try to stay away from people who are visibly sick. Not to mention the fact that many people avoid touching public surfaces.
2. Do you think it's a coincidence that NYC had the highest COVID-19 infection rate of any city in North America?