In addition to combating fare evasion, the new type of gates are expected to make coming and going easier for riders with disabilities, as well as those with strollers or suitcases.
Passengers on Metro-North and Long Island Rail Road trains could face $8 fines if they keep waiting until after the train leaves to activate their mobile tickets.
There was no set number of late activations or late ticket purchases that would trigger the charge, a spokeswoman for the Metropolitan Transportation Authority said.
Gov. Kathy Hochul said the state would spend another $77 million on police patrols in the subway, acknowledging that felony assaults remain stubbornly high.