New York State Route 100B

New York State Route 100B
Dobbs Ferry Road
Map of Westchester County in southeastern New York with NY 100B highlighted in red
Route information
Auxiliary route of NY 100
Maintained by NYSDOT
Length:	2.88 mi (4.63 km)
Existed:	late 1930s – present
Major junctions
West end:	NY 9A in Worthington
	Sprain Brook Parkway in Hartsdale
East end:	NY 119 in Fairview
Location
Counties:	Westchester
Highway system
New York Highways Interstate U.S. State Reference Parkways ← NY 100A NY 100C →

New York State Route 100B (NY 100B) is a 2.88-mile (4.63 km) spur route of NY 100 in Westchester County, New York, in the United States. The route follows Dobbs Ferry Road across the southern part of the town of Greenburgh, connecting NY 9A to NY 119. It does not directly connect to NY 100; however, it intersects NY 100A about 1 mile (1.6 km) west of NY 119. NY 100B was assigned in the late 1930s.

NY 100B begins at an intersection with NY 9A (Saw Mill River Road) in the town of Greenburgh, right next to the New York State Thruway (I-87). Known as Dobbs Ferry Road, NY 100B proceeds northeast through Greenburgh as a two-lane residential street, passing the local Ferncliff Cemetery and bending east into a junction with Park Avenue. Crossing east through Greenburgh, the route crosses south of the Elmwood Country Club. At the east end of the country club, NY 100B crosses into an interchange with the Sprain Brook Parkway, with only ramps to access the northbound direction. After the Sprain Brook, the route continues east through Greenburgh, passing more residences and entering an intersection with NY 100A (West Hartsdale Road / Knollwood Road).

After NY 100A, NY 100B turns northeast in front of the Metropolis Country Club, remaining the two-lane residential street through Greenburgh. Passing south of a large strip mall, the route crosses into a junction with NY 119 (Tarrytown Road) in the center of Greenburgh. The right-of-way for NY 100B merges into NY 119, marking the eastern terminus of NY 100B.