Ultraviolet radiation robots that sanitize subway cars in a flash. Nanoparticles that kill Covid-19 on bus poles and subway seats for three months, non-stop, after just a single application.

In the New York Metropolitan Transportation Authority’s headlong search for ways to woo riders back to the nation’s biggest transit system once the pandemic eases, no idea is too outlandish.

Subways and buses are the circulatory system of the most economically important city in America — they carry more than 5 million people a day during normal times, from grocery clerks to investment bankers, to and from their homes and jobs.

They’ve also likely been a central conduit for the spread of Covid-19 and are seen as among the factors in New York becoming the epicenter of the crisis.