ON THIS DAY: March 23, 2012, North Shore Connector begins service

PITTSBURGH — After nearly two decades of planning, the Port Authority’s light rail system opened a 1.2 mile extension to the North Shore on March 23, 2012. The North Shore Connector tunnels from the Gateway Subway Station, under the Allegheny River and to a pair of new stations by PNC Park and Heinz Field.

The Port Authority first began studying the project in 1994. While many asserted that an extension to Oakland would be preferred, costs were expected to be more than double that of the proposed tunnels to the North Shore.

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North Shore Connector In this file photo from July 11, 2008, workers on Pittsburgh's North Shore Connector Project prepare to remove retaining wall steel from in front of the face of the 500-ton tunnel boring machine, at left, in the pit on Stanwix Street in downtown Pittsburgh. The machine that dug a tunnel to extend the light-rail system under the Allegheny River had broken through Thursday evening. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector A worker on Pittsburgh's North Shore Connector Project prepares to remove retaining wall steel from in front of the face of the 500-ton tunnel boring machine in the pit on Stanwix Street in downtown Pittsburgh, Friday, July 11, 2008. The machine that dug a tunnel to extend the light-rail system under the Allegheny River had broken through Thursday evening. It will be turned around and used to dig a twin tunnel from downtown back to the North Shore, near PNC Park and Heinz Field. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector A crane towers over the pit at the north end of the first tunnel that was bored under the Allegheny River as part of the North Shore Connector project in Pittsburgh, Monday, July 21, 2008. The new section will tie into the subway system in downtown Pittsburgh, connecting it to Pittsburgh's North Shore where the sports complexes are. (AP Photo/Keith Srakocic) (Keith Srakocic/ASSOCIATED PRESS)

North Shore Connector Workers on Pittsburgh's North Shore Connector Project prepare to remove retaining wall steel from in front of the face of the 500-ton tunnel boring machine, at left, in the pit on Stanwix Street in downtown Pittsburgh, Friday, July 11, 2008. The machine that dug a tunnel to extend the light-rail system under the Allegheny River had broken through Thursday evening. It will be turned around and used to dig a twin tunnel, starting at the orange marks on the concrete at right, from downtown back to the North Shore, near PNC Park and Heinz Field. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector On Schedule, $100M Over Budget

North Shore Connector In this photo made with a wide-angle lens, the tops of skyscrapers in Pittsburgh are viewed from the bottom of the pit where the new North Shore Connector meets the light-rail system in downtown Pittsburgh, Tuesday, Oct. 7, 2008. The Port Authority of Allegheny County says the North Shore Connector is a sound investment in mass transit that will serve and further spur development in the area. Critics say it's an example of costly federal spending unlikely to reap much benefit. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector Project Halfway Complete

North Shore Connector Support girders line a section of the tunnel for the new North Shore Connector subway during construction in Pittsburgh, Tuesday, Oct. 7, 2008. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector Workers walk through the lowest point of the tunnel under the Allegheny River that will carry the new North Shore Connector in the Port Authority Transit's new subway that will connect downtown to the major stadiums during construction of the first of the two tunnels in Pittsburgh, Monday, July 21, 2008. The Port Authority of Allegheny County says the North Shore Connector is a sound investment in mass transit that will serve and further spur development in the area. Critics say it's an example of costly federal spending unlikely to reap much benefit. (AP Photo/Keith Srakocic) (Keith Srakocic/ASSOCIATED PRESS)

North Shore Connector A welder joins a section of rebar as other workers knot together the net of steel for the floor before concrete is poured in the tunnel under the Allegheny River for the new North Shore Connector for the subway system in Pittsburgh, Tuesday, Oct. 7, 2008. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector In this photo made with a wide-angle lens, a worker prepares the massive boring machine, right, for it's return trip under the Allegheny River from a pit in downtown Pittsburgh, Tuesday, Oct. 7, 2008. The hole on the left is the first tunnel for the North Shore Connector in the Pittsburgh subway system connecting downtown to the north side and the city's two sports fields. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector A pair of workers stand above the rebar forms for the new platform section of the North Shore Connector between the two major sports stadiums in Pittsburgh, Tuesday, Oct. 7, 2008. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector Workers walk into the two-shaft section where the North Shore Connector will rise up to a platform between the two major sports stadiums in Pittsburgh, Tuesday, Oct. 7, 2008. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector A pair of workers climb the stairway in front of the steel rebar network for concrete to be poured in the pit where the new North Shore Connector surfaces on the north side of the Allegheny River in Pittsburgh, Tuesday, Oct. 7, 2008. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

North Shore Connector Keith Wargo, the project director for the North Shore Connector, talks about how the subway will have an overhead platform as construction continues in the area between the two ball parks on Pittsburgh's north shore of the Allegehny River, Tuesday, Oct. 7, 2008. The Port Authority of Allegheny County says the North Shore Connector is a sound investment in mass transit that will serve and further spur development in the area. Critics say it's an example of costly federal spending unlikely to reap much benefit. (AP Photo/Keith Srakocic) (Keith Srakocic/AP)

Civil War Relics Found At North Shore Connector Site

OTD: North Shore Connector opens OTD: North Shore Connector opens

Take a ride on the North Shore Connector with See & Be Seen

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The project cost $523.4 million, of which 80% was covered by the Federal Transit Administration.

Federal funding for the North Shore Connector was announced on Feb. 6, 2004, and construction began that fall.

Initial excavation on the two tunnels was finished by early 2009.

In 2010, Port Authority officials discovered a consultant installed a cable that wasn’t fire proofed. The Port Authority said the setback cost an addition $1.2 million, which was paid for from the project’s contingency fund.

Construction took five and half years to complete. Dignitaries and politicians enjoyed the first trips to North Side Station and Allegheny Station. Though the first public trips under the Allegheny River were after the “soft opening” on Friday on March 23, regular service did not begin until Sunday, March 25, 2012.

The North Shore Connector has been included in the Port Authority’s Free Fare Zone since its debut.

The formerly controversial project has become more appreciated as development on the North Shore, particularly between PNC Park and Heinz Field, has added numerous offices, restaurants and bars. The North Shore Connector also provides service to the Carnegie Science Center, Rivers Casino and the Allegheny Campus of the Community College of Allegheny County.