On August 31st, 2021, New York & Atlantic Railway Extra 301, with Progress Rail PR20B 301 solo, heads west on Track 2 within the "City Zone" area of the Long Island Rail Road Main Line. The locomotive was heading towards one of the entrances to the East Side Access tunnels at Harold Interlocking for a brief Positive Train Control (PTC) protection enforcement test. The approaches to the ESA tunnels are protected with PTC transponders that prevent access to work/freight trains in the event they are misrouted. Though the NYA does not run on this section of the Main Line, it was necessary to ensure the protection feature operates as intended.