U.S. Route 20 (US 20) is a part of the United States Numbered Highway System that runs from Newport, Oregon, to Boston, Massachusetts. In the U.S. state of New York, US 20 extends from the Pennsylvania state line at Ripley to the Massachusetts state line in the Berkshires. US 20 is the longest surface road in New York. It runs near the Lake Erie shore from Ripley to Buffalo and passes through the southern suburbs of Buffalo, the Finger Lakes, the glacial moraines of Central New York, and the city of Albany before crossing into Massachusetts. US 20 connects to all three major north–south Interstate Highways in Upstate New York: Interstate 390 (I-390) near Avon, I-81 south of Syracuse, and I-87 in Albany by way of Fuller Road Alternate.
With the exception of Albany, it passes directly through no major cities of the state, bypassing Syracuse and Utica by great distances to the south while the New York State Thruway and New York State Route 5 (NY 5), which share its corridor, pass right through or close to them. It skirts the southern and eastern suburbs of Buffalo. It is, however, a major artery in many of the outlying areas it passes through in the hilly fringes of the Allegheny Plateau, often expanding to four lanes (it has no limited-access sections, although many intersecting roads are grade-separated) with extensive commercial strip development. One of these sections, the easterly of two concurrencies with NY 5 across the northern Finger Lakes, is the second-longest surface-road concurrency in New York, behind only the concurrency of I-86 and NY 17 in the Southern Tier, extending from Avon to Auburn.
From Oneida County to Albany, the road follows the historic Cherry Valley Turnpike, built at the beginning of the 19th century to connect Albany and, at the time, the important villages of Sharon Springs, Cherry Valley, Richfield Springs, Cazenovia, and Skaneateles. US 20 itself was assigned in 1926 and was the state's main east–west route from that time until the Thruway was completed in the 1950s.
Route description US 20 enters Western New York closely paralleling the Lake Erie shoreline, the Thruway and NY 5. Passing through the southeastern suburbs of Buffalo, it assumes a due-east heading at Depew, taking it to the NY 5 overlap in Avon. The two roads pass through many of the communities at the north ends of the larger Finger Lakes, splitting in Auburn. Through Central New York and the Central New York Region to its east, US 20 drifts south into the rugged upper reaches of the Allegheny Plateau, distancing itself from the Thruway and NY 5 by as much as at some points.
In the Capital District, the three routes all converge again, and US 20 goes right through downtown Albany, the largest city along its route in New York. Just before crossing the Hudson River, US 20 is joined again by US 9 for its second-longest concurrency, which ends just before the Thruway's Berkshire section in Schodack Center. From there, it drifts southward into the Berkshires, crossing the Massachusetts state line west of Pittsfield.
All but of US 20's alignment in New York is maintained by the New York State Department of Transportation (NYSDOT). In Cayuga County, the section of US 20 in Auburn between NY 38A and the eastern city line is maintained by the city of Auburn. To the east in Albany County, the of US 20 in Albany from the western city line to the north end of the NY 32 overlap is also city-maintained.
Western New York From the state line to the Buffalo suburbs, US 20 is largely a two-lane through road on the same northeastern heading it has followed most of the way from Cleveland. It serves as the main street of the few communities it passes directly through. In the Buffalo area, US 20 begins to head more east, widening to four lanes and becoming a busy regional artery that intersects many other roads of major and minor importance. For the leading into Depew, it runs due north along with NY 78 as part of Transit Road, a busy commercial strip east of the city. At Depew, US 20 leaves Transit Road and begins its journey east across the state. The surrounding countryside returns to farmland by the Genesee County line.
Lake Erie
US 20 enters New York immediately after passing through State Line, Pennsylvania. It remains on the northeasterly course it has been following as I-90, now the New York State Thruway, veers between it and what is now NY 5 in order to remain on level ground. This section of US 20 hugs the foot of the beach ridge to the south of Lake Erie, which is sometimes visible from sections of the highway, in Chautauqua County. A mile and a half () east of the state line, Shortman Road (unsigned NY 950D) leaves to the left for exit 61, the westernmost interchange on the Thruway. Shortly afterward, US 20 reaches its first settlement in New York, the hamlet of Ripley, where it intersects NY 76, the first touring route along US 20 in the state.
Another of two-lane rural road, crossed at its midpoint by the onetime New York Central Railroad and now CSX Transportation mainline, brings US 20 into its first incorporated community, the village of Westfield. Here, NY 394 intersects US 20 in the middle of town on its way to the Thruway's next exit and the hamlet of Barcelona, where it encounters NY 5 and the lake. Beyond Westfield, US 20 begins to drift south, coming farther inland as it heads northeast. to the east, it reaches Fredonia, the largest village along its route so far. 20 intersects with NY 60 at Reed Corners at the eastern edge of Fredonia, which heads north to the neighboring city of Dunkirk. east, NY 39 becomes the first state route to end at US 20. It makes a loop of nearly through the interior of the state to return to US 20 in the Finger Lakes.
Past this junction, the Thruway and US 20 begin to converge in flatter country until they cross as US 20 veers northward south of Silver Creek. US 20 Truck splits off from US 20 in the center of town and rejoins its parent northeast of the village. This portion of the truck route is cosigned as NY 5, and the first of two overlaps between US 20 and NY 5 begins here. The road resumes its northeasterly course to an access road to the Thruway's exit 58 at Irving. After crossing Cattaraugus Creek into Erie County, the concurrency ends, with NY 5 staying close to the lake and US 20 closely paralleling the Thruway. NY 438 leaves this junction to the east, following the creek into Cattaraugus Reservation.
US 20, which is now Southwestern Boulevard, remains straight when paralleling the Thruway, intersecting only one other state highway, NY 249, just east of the village of Farnham, in an stretch that brings it to the outer fringes of the Buffalo–Niagara Falls metropolitan area at Hamburg. Within of the junction with NY 75, which provides access to the Thruway, US 20 intersects US 62, the first U.S. Highway that it encounters in New York. Continuing on, US 20 crosses the Thruway to reach Big Tree. This hamlet was once home to a six-way intersection featuring US 20A, but a late 2000s reconstruction project moved the west end of US 20A to a new junction to the northeast. Like NY 39, US 20A makes a long loop through Wyoming and Livingston counties to return to US 20 in the Finger Lakes.
Buffalo area After the US 20A split, US 20 begins moving away from the lake and trends more to the east-northeast. The road becomes more developed, and, ahead, a major Buffalo landmark looms to the south—Highmark Stadium, home of the Buffalo Bills. On home game days in the fall, traffic clogs the highway as it crosses over the US 219 expressway and curves northeast to reach the eastern terminus of NY 179 at Mile Strip Road. NY 179 offers access to US 219 via an interchange to the west. A half-mile () beyond, the four-lane US 20 intersects the concurrent routes of NY 240 and NY 277, the main route to the village of Orchard Park off to the south.
At the West Seneca town line, US 20 turns due east when Reserve Road merges in from the west. After another mile (), the road makes a 90-degree left turn at NY 187's northern terminus. It is now headed due north as Transit Road, a busy regional route that continues north as far as Lockport. After yet another mile (), NY 16 and NY 78 come in from East Aurora to the southeast. NY 16 continues west to downtown Buffalo while NY 78 turns north to join US 20. Just north of the junction, Transit Road connects to the entrance ramps for an interchange with the NY 400 freeway, US 20's first interchange with a limited-access highway since meeting the Thruway in Irving.
Shops and stores line busy Transit Road on both sides as it divides the towns of West Seneca and Elma. north of NY 400, US 20 and NY 78 reach another state highway, NY 354, near Ebenezer. Not far from that intersection, Cheektowaga and Lancaster replace West Seneca and Elma as the towns on either side of the road. Increasing development and traffic heralds Transit Road's entry into the village of Depew, and, at NY 130, US 20 turns east, ending the overlap and taking the direction it will follow for most of the rest of its crossing of the state.
East of Buffalo Taking the name Broadway, which NY 130 had retained from the city of Buffalo, US 20 goes through downtown Depew before it proceeds into the neighboring village of Lancaster. It returns to a rural two-lane road beyond Lancaster, passing through a traffic light only at the small village of Alden before crossing into Genesee County. In the town of Darien, US 20 continues straight past Darien Lakes State Park to the junction with NY 77 at Darien Center, where much summertime traffic turns north toward nearby Six Flags Darien Lake. NY 238 forks off to the southeast towards Attica at a junction to the east of Darien Center.
Past the junction with NY 238, which forks off to the southeast toward Attica, the highway begins going straight up and down into the creek valleys here at the northern fringe of the Allegheny Plateau. Passing lanes are sometimes available on the downhill sections, particularly in the next community to the east, Alexander, where another route to Attica, NY 98 crosses via an overpass. This allows traffic to continue at a high speed through the surrounding dairy and sod farms up the other side and into Bethany, the next town, whose four four-way intersections offer only blinking yellow lights and no stop or yield traffic control devices to slow down drivers.
This unbroken stretch ends with a new light shortly into the next town, Pavilion, where NY 63 crosses at an angle. Here, traffic bound for the Southern Tier and farther turn right to eventually connect to I-390 at Mount Morris. The four-lane US 20 straightaway continues across the town, with NY 19 also on an overpass at Pavilion Center. US 20 goes on past the Livingston County line to the east, where it finally drops the Broadway name. After another , the route enters the hamlet of Fraser, where the north–south NY 36 crosses US 20 on its way from Mount Morris to Caledonia. US 20 continues on to the community of Canawaugus to the east, where NY 5 enters from the village of Caledonia to the northwest and rejoins US 20. The two routes continue east from here to the village of Avon.
NY 5 concurrency and Finger Lakes