The Park Avenue main line, which consists of the Park Avenue Tunnel and the Park Avenue Viaduct, is a railroad line in the New York City borough of Manhattan, running entirely along Park Avenue. The line carries four tracks of the Metro-North Railroad as a tunnel from Grand Central Terminal at 42nd Street to a portal at 97th Street, where it rises to a viaduct north of 99th Street and continues over the Harlem River into the Bronx over the Park Avenue Bridge. During rush hours, Metro-North uses three of the four tracks in the peak direction.
Originally constructed in the mid-19th century as a New York and Harlem Railroad route, the Park Avenue main line was initially a street railroad and ran to what is now Lower Manhattan. It was gradually truncated through the 1860s, until Grand Central Depot was opened at 42nd Street in 1871. The line was placed in a grade-separated structure in the late 19th century, as part of the Fourth Avenue and Park Avenue Improvement projects, and was electrified in the first decade of the 20th century as part of the construction of Grand Central Terminal. Since then, several improvement and rehabilitation projects have been made along the main line. From 2023 to 2026, the Metropolitan Transportation Authority (MTA) carried out a major project to replace the viaduct north of 99th Street.
Line description
The Park Avenue main line originates at Grand Central Terminal to the south, which is located at 42nd Street. It consists of various train yards and interlockings between 42nd and 59th Streets consisting of 47 tracks between 45th and 51st Streets, 10 tracks from 51st to 57th Streets, and then finally narrows to four tracks at 59th Street. At this section, known as the Grand Central Trainshed, the surrounding streets are suspended over the Park Avenue line via various viaducts.
The line runs in two parallel tunnels from 59th to 97th Streets, with each tunnel carrying two tracks. Initially, the line enters fully-enclosed brick tunnels between 67th and 71st Streets, and later between 80th and 96th Streets. The remainder of this segment is located in a beam tunnel structure; the roof of the tunnel is supported on I-beams, and the cross-streets are carried on steel-beam bridges. The tunnels have a vertical clearance of above the running rails. At 97th Street, the line rises onto a viaduct and continues above the median of Park Avenue until it reaches 132nd Street. There, the line crosses the Park Avenue Bridge, a vertical lift bridge, and traverses the Harlem River. The line continues into the Bronx, where it diverges into the Hudson Line and the Harlem Line.
Internally, the Metropolitan Transportation Authority (MTA) refers to the entirety of the Park Avenue main line's tracks as part of the Hudson Line. According to this internal designation, the Harlem and New Haven Lines merge into the Hudson Line in the Bronx, and the Hudson Line is the only line that continues into Grand Central Terminal.
History Street railway The Harlem Line in its current form originated from the New York and Harlem Railroad (NY&H), which was the first streetcar company in the United States and in the world. It was franchised on April 25, 1831, to run between the original city core in Lower Manhattan to the suburb of Harlem, several miles to the north on Manhattan Island. The railroad's charter allowed the line to run between 23rd Street and any point on the Harlem River between Eighth and Third Avenues, with a branch running to the Hudson River, encompassing most of the island. The company initially had a stock limit of $350,000 ().
While the NY&H wanted to run the line as a steam line, the city made it use horse power south of 14th Street. On September 13, 1831, the Board of Directors of the railroad approved its route along Fourth Avenue (later renamed Park Avenue) from 23rd Street to the Harlem River. On April 6, 1832, the railroad's charter was amended to allow the line to be extended south to 14th Street.
On May 2, 1832, the City Common Council secretly granted the NY&H the right to lay track along Broadway to City Hall and Bowling Green. The general public objected once it found out, and a fraudulent map was circulated at the time, showing that the railroad would take up of the street when it really would only take up . Newspaper editors also objected to the railroad's plan. In spring 1833, the railroad published a pamphlet titled "A Statement of Facts in Relation to the Origin, Progress, and Prospects of the New-York and Harlem Railroad Company" to refute objections to its plan. On March 1, 1833, a meeting was held in Tammany Hall concerning the issue. At the meeting, cabdrivers and cab owners came out against the railroad. After the meeting, the crowd tore up some of the railroad's track and the council withdrew its Broadway agreement with the railroad. The NY&H was eventually extended downtown in 1839, but along a different route.
Ground was broken on the NY&H's construction on February 23, 1832, at Murray Hill on Fourth Avenue. At the ceremony, Vice President of the railroad John Mason hinted at the railroad's ambitions, saying that while the railroad's principal objective was local, its higher importance was to get to Albany. In 1832, the New York State Legislature authorized the company to raise its stock limit to $500,000 on the condition that the line be completed to the Harlem River by 1835. That November, two horsecars—"John Mason" and "President"—built by John Stephenson were ready for operation, both of which were named after John Mason, who had become the railroad's president in August.
On April 27, 1837, an act was passed in the State Legislature to widen Fourth Avenue between 32nd Street and the Harlem River to provide room for the railroad. The street was widened by on either side, making the street wide. The company ceded the title for the land that would be occupied by Fourth Avenue to the city in exchange for permission to occupy it. In that same year, the railroad purchased six city lots at Fourth Avenue and 26th Street for $7,000, for the construction of car barns and stables. A tunnel stretching was completed through Prospect Hill, one of the highest points on the East Side of Manhattan, between modern 92nd Street and 95th Street, in 1837. The New York City Landmarks Preservation Commission claims that this is the oldest railroad tunnel in the United States.
The first section of the NY&H, along Bowery from Prince Street north to 14th Street, consisting of , opened to the public on November 26, 1832. Service was then extended northward along Fourth Avenue to 32nd Street on June 10, 1833. Work on the Murray Hill rock cut began in autumn, 1833 and was completed in 1834, and service along a -long segment to 85th Street in Yorkville opened on May 1, 1834. Service ran every 15 minutes between 5 a.m. and 8 p.m., and ran every 60 minutes to 10 p.m.. A one-way fare cost 12.5 cents. Service was extended north, finally reaching Harlem—then a small suburb—on October 26, 1837, with the Yorkville Tunnel constructed to reach this point.
Service then extended further south. On May 4, 1839, the line was extended south along The Bowery, Broome Street and Centre Street to City Hall, at Centre Street and Park Row. Service was extended south on November 26, 1852, along Park Row to Astor House at Park Row and Broadway. In 1851, work began to convert the Murray Hill rock cut into a tunnel, and in October of that year the City Common Council ordered that a -wide planted median be installed atop the tunnel between 34th Street and 38th Street. Real estate developers who purchased adjacent lots named this section of Fourth Avenue Park Avenue, which would later be applied to the remainder of the street. The development of the area increased once the rock cut was decked-over.
On October 6, 1871, the depot used by the NY&H was changed from 26th Street and Fourth Avenue to Grand Central Depot, at 42nd Street. Since there were originally no grade-separated crossings of the railroads between 42nd and 59th Streets, there were frequent accidents; seven people died within 12 days of the move to Grand Central.
On April 1, 1873, the NY&H was leased for 401 years to the New York Central and Hudson River Railroad (later New York Central Railroad). The line then became the Harlem Division of the New York Central. The lease did not include the portion of the line using horse cars. Horse cars were replaced with an underground trolley system in 1897, when it was leased to the Metropolitan Street Railway Company.
Fourth Avenue Improvement
The confluence of tracks to the north of Grand Central was considered to be the city's "most fearful death-trap" by The New York Times in 1872, and large meetings were held to protest the deaths caused by collisions between trains and pedestrians. The New York State Legislature passed legislation in 1872, requiring that of NY&H tracks between Grand Central and the Harlem River be placed underground. The law set up a Board of Engineers to manage the project, which was known as the Fourth Avenue Improvement. The law stated that the authorization for two additional tracks was given "for the purpose of facilitating rapid transit and accommodating local traffic": these tracks were built on the same level and, as part of the project, four local stations were built.
The project's cost was split between the New York Central, run by Commodore Vanderbilt, and New York City, whose payment of $3.2 million was to be recouped from increased taxes on future development. The project was divided into three sections: 45th Street to 49th Street, 49th Street to 79th Street, and 79th Street to the Harlem River. The line was sunk into a tunnel between 59th Street and 96th Street through Mount Pleasant, known as the Yorkville Tunnel. The -long section in the Harlem flats between 98th Street and midway between 115th and 116th Streets was built as a stone viaduct, and reached its highest point at 114th Street. The stone viaduct adjoined earth embankments.
To the north of this section, from 125th Street to 130th Street at the Harlem River, the line was constructed below-grade. Arched brick tunnels were built wherever sufficient room allowed for it. Beam tunnels were constructed where the headway was too small for an arched tunnel, and, where room did not allow for that, open cuts were constructed. The rock tunnels were built between 92nd Street and the north side of 94th Street. Between 48th Street and 56th Street, the line was placed into a shallow open cut. To allow people and vehicles to cross over the rail line, eight pedestrian bridges were built over the line between 45th Street and 56th Street, and vehicular overpasses were built at 45th Street and 48th Street. To cover the frequent openings between 50th Street and 96th Street for ventilation, the roadway's center was landscaped and fenced-off. These malls were narrowed significantly in the early 1930s to accommodate additional lanes of traffic. These malls and the street's great width distinguish the street above, and contribute to Park Avenue's identity as a sought-after residential address.