[9] An additional 60-car order is currently finishing delivery in response to increased ridership and usage on Shore Line East.

The overhead wire is at a nominal 12.5 kV AC (60 Hz) power from overhead lines via pantographs for operation from Pelham, New York to New Haven, Connecticut (as well as along the New Canaan Branch), and 25 kV AC (60 Hz) power from catenary for operation along the Shore Line East route east of New Haven to New London, Connecticut.

[10] In the event that a disabled rider boards a car, all cyclists must move their bicycles to the entry vestibule.

In spite of the hook installation, during peak travel periods only folding bicycles are permitted aboard most Metro North trains.

An additional safety feature is the installation of intercom systems that customers can use to contact the train crew in case of emergency.

Other features included curved luggage racks, coat hooks, electrical outlets to charge personal devices, and LED displays that show that next stop and automated announcements.

[21][1][22][23] The first run of the initial eight-car set (consisting of cars 9114, 9115, 9116, 9117, 9112, 9113, 9108, and 9109) originated in Stamford at 10:30 am, arriving in Grand Central Terminal at 11:28 am.

A total of ten eight-car train sets were slated to enter service by the end of the year.

[25] Two months later, an investigative report by WABC-TV's news operation examined correspondence between Kawasaki and Metro-North over the delays in introducing the cars.

At the time it had been claimed the cars merely had software problems, but the documents reporters obtained under New York's Freedom of Information Law showed Kawasaki repeatedly asking for deadline extensions over issues such as bad weather and financial difficulties at the company that supplied the onboard toilets.

Railroad officials complained in emails reviewed by the channel that some of the requests "defie[d] logic" and were a waste of time.

[26] On July 20, 2011, the Connecticut Department of Transportation announced the order of 25 unpowered M8 railcars, with options for up to 25 more, at a cost of $93 million to provide additional service.

[27] On October 16, 2012, Metro-North announced that they would be installing 15 weekday and 30 weekend M8 trains to their schedule to accommodate increased ridership.