Some members of the MTA board are once again advocating for subway platform doors.

In the past, the MTA has talked of launching a pilot program to test platform doors, but the agency has never followed through.

Board members we spoke to say platform doors, while costly, would protect subway riders and help ease overcrowding.

"Those platform doors, which are in use in London, in use in Paris and in use in many other cities, and which have had the effect, the direct effect, of limiting overcrowding," said board member Charles Moerdler.

"I think many parents of young people of all ages would be reassured with some protective devices, particularly at the overcrowded stations," said board member David Jones.

Only the Airtrain in Queens currently uses platform doors.