The estimated cost to reopen PATCO's long-shuttered Franklin Square subway station in Old City is at least $18.5 million, a new study has found.

That's about 50 percent more than transit officials expected.

The study, requested last year by PATCO's parent, the Delaware River Port Authority, estimates 1,300 riders would use the station each day, but that nearly all would be current riders who now use the Eighth and Market Streets station.

The port authority has been considering reopening the "ghost station" beneath Sixth and Race Streets for years, and the agency included $500,000 in its current capital budget to reexamine the issue.

The new study makes no recommendation about reopening the station, which has been closed since 1979.

The cost estimated by the study is 50 percent higher than the $12 million estimate in the authority's budget. And, the study said, an additional $8 million would be needed to add improvements such as escalators and an entrance on the south side of Race.

The rebirth of the once-seedy Franklin Square park above the station and new development nearby has brought renewed bustle to the area and thus a renewed interest in using the subway station.

For more than five years, the authority has proposed and then shelved plans to reopen the station, citing financial constraints.

John "Johnny Doc" Dougherty, the Philadelphia labor leader who last year represented Pennsylvania Auditor General Eugene DePasquale on the port authority's board, was the leading advocate for reopening the station. He is no longer on the board.

The Franklin Square station opened in 1936 as the easternmost Philadelphia stop on the Camden-Philadelphia rail line owned by the Delaware River Joint Commission and operated by the Philadelphia Rapid Transit Co.

The station closed because it got little use, but increased activity on the riverfront during World War II prompted its reopening.

Closed again after the war, the station was reactivated in 1953 when the commuter rail line was extended from Eighth and Market Streets to 15th and Locust Streets. However, it was closed again for lack of use. PATCO took over the line in 1969.

In 1976, when Philadelphia was celebrating the Bicentennial, PATCO spent $1.1 million to renovate and reopen the Franklin Square station. It closed again in 1979.

The station now serves as an occasional storage site for construction crews working in the PATCO tunnel. It has electrical power to operate the dim emergency lights that remain and provide air-compressor power for rail switches.

The station was last used by the public in February 2014, when police and firefighters opened emergency exits there to rescue passengers stranded after a crowded train broke down.