Producers for the latest Batman movie were ready to settle on the subway in Pittsburgh, Pa., as the underground urban railroad for Gotham City. They liked the location, but it wasn’t perfect.

An assistant location manager happened to mention that when he went to NJIT, there was a subway in Newark he took to school.

Christopher Nolan, director of "The Dark Knight Rises," visited Newark with about 100 other crew members and fell in love with the subway for its urban feel. The Military Park Station on Broad Street became the setting for the meeting between Batman and Catwoman as they formed their alliance.

The producers can be forgiven if they never knew the subway existed. It’s perhaps the best-kept transportation secret in the state — a small hidden subway under New Jersey’s largest city where the cars are clean and efficient and on-time rates of 98 and 99 percent are recorded.

Ask someone on the street of any New Jersey town where you can find the subway, chances are good they’ll direct you to the sandwich shop.

"A lot of people, when they find out it’s here, say they’re shocked," said Greg Woods, assistant general manager of the system, called the Newark City Subway when it was built in 1935 and now under the umbrella of the Newark Light Rail.

"They can’t believe all this infrastructure’s here and has been here for so long," he said. "And it’s amazing when you see it for the first time — just like I was years ago when I moved here (from California). ‘You have a subway?!’"

Platforms look like miniature versions of those in the New York subways, complete with white subway tiling on the walls.

"Please stand clear of the closing doors," the voice tells Newark subway passengers, just like those in New York — except you can clearly hear the announcement in Newark.

No third rail on these subways, though.

"New York, New York — a wonderful town. The Bronx is up and the Battery’s down. The people ride in a hole in the ground," dancing sailors sang in the musical, "On The Town."

They ride in a hole in the ground in Newark, too.

The subway trolley cars, known as LRVs, for light rail vehicles, are run by AC electric power. The underground portion is brief, from Newark Penn Station to the third stop 1.2 miles away at Warren and Lock streets in the city, and those taking just that trip can pay the "underground station fare" of 70 cents.

It costs $1.50 for the full 5.3 mile, 20-minute ride from Newark Penn Station to Grove Street in Bloomfield Township, where there is a light rail vehicle maintenance facility and the only stop that has customer parking.

A second segment opened in 2006, spanning the one mile from Newark Penn Station, near Route 21 and Market Street, to the Newark Broad Street Station, at Broad Street and Lackawanna Avenue, making stops in between that include Riverfront Stadium and the New Jersey Performing Arts Center. That’s the same year the system name was changed from Newark City Subway to Newark Light Rail.

The system attracts between 18,000 and 22,000 riders on weekdays, largely composed of students from NJIT and Rutgers-Newark and office workers going to downtown Newark.

Newark native Penrod Parker moved out to Hackettstown, but still makes use of the Newark subway, taking a train from Hackettstown to Newark Broad Street Station, then hopping on a light rail vehicle to Newark Penn Station.

"Once you get outside of Newark, if you’re not born and raised in this area, you probably wouldn’t know," he said. "When I was in college and I would bring friends into the city and we’d take the subway, they’d go, "They’ve got subways?!’"

"It’s a great system," added Parker, 68, as he grabbed a ticket below Newark Penn Station. "I started using the subway when I was 15 years old, going from Broad Street to Penn Station. It was one of the fastest ways to go down, particularly in the winter or inclement weather. You could just run down in the subway, jump on a train and you’re here."

Kirk Wassong retired from NJ Transit as a supervisor after a career that spanned nearly four decades.

He said construction of the subway system started near the beginning of the Great Depression in 1929 and it was opened in 1935 along the old Morris Canal right-of-way.

The old subway cars were 2600 series cars, built in 1917, that lasted until 1952, Wassong said. In 1951, Public Service Coordinated Transport bought 30 Presidents’ Conference Committee cars from Twin City Rapid Transit — with the most comfortable seats you ever felt — and repainted the cars in gray and light gray.

They ran for a half-century — an idea to run buses underground in the tunnel was scrapped in the early 1950s — until the longer, modern light rail vehicles, which can travel up to 50 mph and hold 68 seated passengers and 122 standees, arrived in 2001.

"Because it’s underground in downtown Newark and it’s in a cut pretty much the rest of the line, people don’t even see them — it’s hidden," Wassong said. "And when you say, ‘Oh, I work for the subway.’ "What subway? Newark doesn’t have a subway.’"

Plenty of people found the subway when "The Dark Knight Rises" filmed for two weekdays in Newark in November 2011.

The movie’s stars, Christian Bale and Essex County’s Anne Hathaway, who had been given safety training earlier by NJ Transit on how to navigate the tracks, filmed their scene.

Raymond Boulevard was shut down, scenes were shot at Newark City Hall and police cars and subway maps reflected Gotham City as people in the streets shouted, "Go Batman."

"This was a station in Gotham City. So all of the signage in the station was changed over, the lighting was changed, the police cars that they used in some of the outside production were labeled Gotham City and there were police in Gotham City uniforms running through the station," said Neal Fitzsimmons, director of service planning for NJ Transit’s light rail system. "So it was a couple of days worth of Gotham for the Newark Light Rail line and Military Park Station."

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