Interstate 87 is defined as part of Interstate Route Connector 512 and part of Interstate Route 502 in New York Highway Law ¡ì 340-a. Interstate 87 begins at an intersection with the Bruckner Expressway (I-278) at the Triborough Bridge. For the next 8.4 miles, Interstate 87 is known as the Major William Francis Deegan Expressway, which travels through the Bronx. The road, formerly New York State Route 1B, was proposed in 1936 by the Regional Plan Association to relieve traffic issues. The road was first opened in 1939, as a 1.5 mile long highway, ending at Grand Concourse. Robert Moses worked on getting the expressway to go farther north, with a proposed ending at the to-be New York State Thruway. By 1956, the Major Deegan was completed, gaining Interstate status soon after.
The first exit along the Major Deegan northbound is for Willis Avenue and the nearby Third Avenue Bridge. There is an exit before this going southbound, for Brook Avenue. At 1.20 miles, Grand Concourse interchanges at Exit 3. East 149th Street is the next exit, which heads into the heart of the Bronx. Exit 5, which is signed for East 161st Street, actually lets off at Jerome Avenue. Exit 6 is only accessible via Exit 5 (going northbound) and is for East 153rd Street. Exit 7 is for the Cross Bronx Expressway and Trans-Manhattan Expressway, both of which are signed as I-95 and US 1. Exit 8 is for West 179th Street, which becomes Burnside Avenue soon after. Exit 9 parallels the Major Deegan for ending at West Fordham Road.
U.S. Route 9 now parallels the Major Deegan, which is accessible via Exit 10 for West 230th Street. Interstate 87 then enters Van Cortlandt Park and interchanges with Van Cortlandt Park South at Exit 11. Exit 12 is for the Henry Hudson Parkway and Saw Mill River Parkway, both of which are accessible by the Mosholu Parkway. Exit 13 is for East 233rd Street and Jerome Avenue. Exit 14 is at the northern end of Van Cortlandt Park, is for McLean Ave. The Major Deegan crosses into Westchester and becomes the New York State Thruway, a 496-mile, state-wide highway.
New York State Thruway
The section of highway between the New York City line and the junction with Interstate 90 at Albany is part of the New York State Thruway, for which it was originally constructed in the middle 1950s. The section received its designation as Interstate 87 in 1958.
When Interstate 87 enters Westchester, the road is located in the Yonkers. The first exit going northbound is for Hall Place, while going southbound it is for McLean Avenue. (McLean Avenue is Exit 14 going northbound on the Major Deegan. There is no southbound Exit 14.) Yonkers Avenue interchanges at 9.80 miles. Present just off Exit 2 is Yonkers Raceway. Exit 3 is for Miles Square Road, which interchanges just after the Cross County Shopping Center. Exit 4 is for the Cross County Parkway, which interchanges just after the shopping center. Exit 5 follows a frontage road, which heads for New York State Route 100 and the Sprain Brook Parkway. Soon after, Tuckahoe Road interchanges just before leaving Yonkers. Exit 6A is for Stew Leonard Drive, which is just a road for Sprain Ridge Park.
As Interstate 87 heads northward, New York State Route 9A begins to parallel, interchanging at Exit 7. The Saw Mill River Parkway is also parallel, intersecting at Exit 7A. Before Exit 8, the Ardsley Service Area is accessible northbound. Exit 8 is for Interstate 287, beginning a concurrency for the next 19 miles. The exit is also the access for the Cross-Westchester Expressway. Exit 9 is the final exit before the Tappan Zee Bridge. The exit is for New York State Route 119 and the nearby U.S. Route 9. All trucks with Class A and Class B explosives must leave at Exit 9. Interstates 287 and 87 cross the Tappan Zee and enter Rockland County.
Interstate 87 begins a 25 mile stretch in Rockland County. Exit 10 is the first exit after the Tappan Zee and is for U.S. Route 9W in Nyack. Exit 11 is in downtown Nyack, for Route 9W going northbound and New York State Route 59 going southbound. 87 then passes the Mountainview Nature County Park as it reaches Exit 12, which is located in the outskirts of Nyack. Exit 12 is a folded-diamond interchange for New York State Route 303 and Palisades Center Mall. The first highway in 9.63 miles interchanges at Exit 13, the Palisades Interstate Parkway.
The road has two current spur routes in Upstate New York. I-287 connects with its parent in a 19-mile (31 km) long concurrency near the southern end of the highway, with I-87 signed as south, and I-287 signed as east. It is a partial beltway around New York City. West of the concurrency, it loops around New York to meet the New Jersey Turnpike in Middlesex County, New Jersey. East of the concurrency, I-287 continues as the Cross Westchester Expressway to end at I-95 (the New England Thruway) in Rye, New York, near the Connecticut border. Note that I-287 leaves New York state, while its parent does not, making I-287 one of only a few three-digit interstates that goes through more states than its parent. I-587 is less than 2 miles (3.2 km) long. It is unusual in that it has no interchanges along its length: its eastern terminus is at a signalized intersection, while its western terminus is at a roundabout (where it connects to Interstate 87).
North of Albany, Interstate 87 is known as the Adirondack Northway (or simply the Northway) and continues all the way to the Canada-US border. This segment was built in 1967 to provide a direct route between New York City and Montreal for Expo 67. The same year, Parade Magazine designated the Northway as America's Most Scenic Highway. A long stretch of the Northway through the Adirondack Park is a "dark zone" for cell phone service. A number of recent tragedies have occurred when drivers crashed off the road and could not summon help, prompting calls from local officials to add new wireless towers to address the problem, and warning signs to inform drivers of the dark zone.
The southern portion of the Northway through Colonie and Saratoga County is now a heavily traveled commuter route. Since the highway's construction, Saratoga County has become the fastest growing area of the Capital District, and indeed all of upstate New York.
The Northway's southern terminus is at US 20 in Guilderland, and the 0.86-mile (1.38 km) section of the Northway that is not signed as Interstate 87 (but runs parallel to, and in proximity to, the Thruway/I-87) is maintained by NYSDOT as New York State Route 910F (an unsigned reference route), also known as Fuller Road Alternate. Plans by the Thruway Authority to construct E-ZPass Only lanes to connect directly to the Thruway, to ease congestion at Exit 24, have been discussed for years.
The Delaware and Hudson Railroad's Troy and Schenectady branch would have been bisected by the construction of I-87. Since they still had customers on that branch, the railroad crossed the Interstate at grade. This lasted four years, until 1963.
Between exits 2 and 4, I-87 closely parallels Wolf Road, a business thoroughfare maintained by NYSDOT as unsigned New York State Route 910B in the Town of Colonie. Wolf Road forks from I-87 at the cloverleaf interchange of I-87 exit 2 and runs along the eastern edge of the expressway for 1.91 miles (3.07 km) before rejoining I-87 at exit 4 (County Route 151, Albany Shaker Road) southeast of Albany International Airport. Wolf Road serves as a main access point for Colonie Center, one of the Capital District's largest enclosed shopping malls, from I-87.
At milepost 100, going southbound, there is a United States Customs border patrol station. This was added after the 2001 terrorist attacks.