MTA NYC Transit officials are warning customers of the dangers of walking or riding between subway cars, with a new public service announcement campaign that started last week and continues to be in development.

Seven people died while walking or riding between subway cars in 2018, including four people in December alone. Five people died during such activity in 2017, and another five in 2016.

Digital displays in stations began airing a PSA last week that stated simply and directly: “3 people have died this month walking between moving subway cars. Don’t take the risk. Please ride safely.” The PSA was later updated to note four people after an incident on Dec. 29, and starting today says “7 people died in 2018…”

An announcement in subway cars that began this week says: “Hello everyone. It’s against the rules and very dangerous to ride or walk between train cars, unless it’s an emergency, or if you’re directed by a police officer or MTA crew member. Have a safe day, and thank you for riding with us.”

“Riding or walking between subway cars without supervision is dangerous and can cost a person their life,” NYC Transit President Andy Byford said in a statement. “It’s not worth it and we’re urging our customers not to do it.”

Transit officials are also working on in-car signage to reinforce and amplify the message that stepping between subway cars without official supervision is dangerous. Existing signage already notes that the act is prohibited.

The first responder investigation and recovery work associated with these fatalities — during which power needs to be cut from the tracks — can also cause significant train delays and crowding conditions on platforms. There were approximately 500 delays in 2018 recorded as being caused by a person killed while between moving train cars, including about 190 delays from one incident alone, in which a person died on Dec. 21 while walking between cars on the 2 line near 110 St.