The MTA has quietly revived efforts to run more subway trains without conductors – a controversial cost-cutting move it shelved three years ago, the Daily News has learned.

Metropolitan Transportation Authority officials have recently discussed expanding the use of a reduced-staffing scheme – called One Person Train Operation, or OPTO. The practice of running trains with a crew of one has been limited for years to a handful of shuttles or lesser lines, like the G, during off-peak hours.

Union officials and some transit advocates contend conductorless trains on busier lines would put riders at greater risk in emergencies, including situations requiring evacuations through tunnels.

The MTA took conductors off the L line in 2005, but had to put them back after an arbitrator ruled that its contract with Transport Workers Union Local 100 required approval by the union. The following year, the same arbitrator stopped the MTA from taking conductors off G trains on weekdays.

After the second ruling, the MTA stopped putting OPTO plans in its annual budgets and four-year fiscal plans.

Sources told The Daily News that the MTA is again seeking the staffing change as a way to save money.

Transit officials have argued in the past that trains can run safely with just a motorman, as police and firefighters quickly respond to track fires and other emergencies. Officials also have argued that train evacuations between stations are infrequent and have been conducted without passengers suffering injuries.

(Source: NYDN)