The MTA issued "travel papers" to their workers

On March 17th, a few days before New York issued a shelter in place order, the Metropolitan Transportation Authority issued "travel papers" to their employees to prepare for a potential coronavirus curfew. The NY Daily News reports:

If non-emergency travel is restricted, workers can show law enforcement officials the letter if they're stopped on the way to work.

"This letter along with current New York CIty Transit identification identifies this individual as an essential employee who is required to travel during the curfew imposed due to the Coronavirus emergency," states the letter, which is signed by the Metropolitan Transportation Authority's Police Department's acting chief Joseph McGrann. "Please give this individual due consideration during this crisis."

MTA spokeswoman Abbey Collins said the letter was distributed on Monday to a "limited number of NYCT bus employees living in New Jersey" because the state's Gov. Murphy suggested imposing a statewide curfew between 8 p.m. and 5 a.m. (source)