The highway traverses two distinct areas, loosely separated by the Tioga–Broome county line. While the Tioga County section serves small communities and sections of undeveloped, rural areas, the portion in Broome County is a major arterial that runs through Binghamton's western suburbs. The easternmost two blocks of NY 434 in the city of Binghamton are locally maintained while the remainder of the route is maintained by the
New York State Department of Transportation (NYSDOT).
Tioga County NY 434 begins south of the
village of Owego at an intersection with
NY 96. The highway heads to the east as a two-lane road, closely paralleling
I-86/
NY 17 as it runs along the southern edge of the
Susquehanna River valley. The first junction along the route leads to exit 64, the first of three exits directly connecting NY 434 to the nearby freeway. Continuing on, NY 434 serves a
housing tract and a cluster of commercial properties at the southeastern edge of the village before heading into less developed areas of the town. For most of the next , NY 434 runs directly alongside the eastbound lanes of the freeway, separated by only a fence in all but a handful of areas. East of the village limits, I-86 and NY 434 curve to the southeast, mirroring a similar turn in the course of the river and its surrounding valley. The route continues through forests and mostly undeveloped fields, serving exit 65 of I-86/NY 17 and passing by Owego Town Court ahead of another bend in the river. I-86 and NY 434 again turn to match, proceeding generally eastward across an area of marshland along the southern edge of the river valley. Past the marsh, the valley swerves southward for a second time, taking the Susquehanna River and the two roads alongside it into an area with firmer ground. Here, NY 434 begins to run along a line of homes and businesses that mark the northern edge of the
hamlet of Apalachin. The highway heads generally southeasterly through the community to Apalachin's central business district, largely centered around NY 434's junction with
County Route 41 (CR 41). Continuing on, the route passes through a small, undeveloped area at an intersection with
NY 962J, a signed
reference route linking NY 434 to part of exit 66 of I-86/NY 17 and to
NY 17C on the north bank of the river. Past NY 962J, the path of the Susquehanna River turns again, taking on a northeasterly track toward the
Broome County line. NY 434 bends northeastward as a result, running past several scattered businesses on the outskirts of Apalachin before finally leaving the community. Occasional stretches of homes continue to follow the route to the county line, where the road widens from two to four lanes and becomes a
divided highway.
Broome County Across the county line in the town of
Vestal, NY 434 assumes the name Vestal Parkway and heads into more densely populated areas that serve as
Binghamton's suburbs. The homes alongside the road are replaced by businesses in the hamlet of Vestal, the first of several large communities that NY 434 serves in Broome County's progressively widening river valley. It becomes a major commercial strip as it proceeds northeastward through the community, a trait that NY 434 retains throughout the Binghamton suburbs. Just east of Vestal's central business direct, the highway intersects
NY 26 at a
partial cloverleaf interchange just south of NY 26's full
cloverleaf with I-86/NY 17. Past NY 26, I-86 heads across the Susquehanna River, leaving NY 434 as the primary highway on the river's south bank. The
strip malls and plazas along NY 434 become progressively larger in size as the highway heads east, leading to two large shopping malls at a junction with Sycamore Street about east of the hamlet of Vestal. The pair of plazas feature several national chain stores, such as
Walmart,
Target,
Sam's Club, and
Lowe's, and a handful of others are located nearby at various points along NY 434. Continuing on, the route reaches the campus of
Binghamton University, located adjacent to a
trumpet interchange that links NY 434 to
NY 201, a north–south freeway connecting the college to
Johnson City on the north bank of the Susquehanna. The route remains on an easterly path to the edge of the campus, where it turns southeast to directly run alongside the river for the first time. At this point, the businesses begin to taper off, giving way to dense residential neighborhoods as the road crosses into the Binghamton city limits. NY 434 remains a four-lane divided highway for its first in the city, following the Susquehanna River along the north edge of a vast neighborhood that comprises the south half of Binghamton. It soon approaches the vicinity of
downtown Binghamton, where the route connects to Pennsylvania Avenue by way of an interchange located across the river from the city's center. Another grade-separated junction with Conklin Avenue follows, at which point NY 434 turns northward and crosses the river into downtown as State Street. On the north bank of the river, NY 434 meets
NY 363, a freeway linking downtown to the Southern Tier Expressway north of the city. NY 434 continues on, narrowing to two divided then undivided lanes for its final two blocks as it passes the
Broome County Veterans Memorial Arena and ends at a junction with
US 11 (Court Street). ==History==