Designation

When NY 270 was assigned as part of the 1930 renumbering of state highways in New York, it began at Main Street (NY 5) in the hamlet of Eggertsville and followed Eggert Road north to Millersport Highway. Here, it turned to the northeast, utilizing what is now NY 263 to the modern campus of SUNY Buffalo. While today's Millersport Highway veers east to bypass the college, the highway originally went straight through the grounds, partially by way of what is now St. Rita's Lane. North of Ellicott Creek, NY 270 proceeded to Getzville via North Forest and Stahl Roads. At Getzville, NY 270 joined its modern alignment and followed it to Saunders Settlement Road (now NY 31), where it turned northeast onto Saunders Settlement Road for a short distance to Upper Mountain Road, where it ended at NY 3 outside of Lockport.^[2]

Both extents of NY 270 were realigned slightly by 1932. In the vicinity of Eggertsville, the route was reconfigured to follow Bailey Avenue and Grover Cleveland Highway between Main Street and Eggert Road. Near Lockport, NY 270 was shifted southward onto Hinman Road and Ohio Street. The latter change was made as part of a larger realignment of NY 3 through central Niagara County.^[5] The realignment of NY 270 near Lockport was short-lived as the route was moved back onto Campbell Boulevard c. 1935; however, it was also truncated to end at the junction of Campbell Boulevard and Saunders Settlement Road.^[6][7] NY 270 was truncated again in the mid-1930s after U.S. Route 62 (US 62) and NY 18 were realigned to follow Bailey Avenue between Main Street and Sheridan Drive (NY 324).^[8][9]

Truncations

By 1935, NY 270 was realigned to bypass North Forest and Stahl Roads by way of a new section of Millersport Highway.^[7] In the early 1940s, NY 270 was extended north over Junction Road to meet US 104 at Warrens Corners. Around the same time, NY 263 was extended southwest to Buffalo over NY 270.^[10][11] Initially, NY 263 overlapped with NY 270 along Millersport Highway; however, the overlap was eliminated in the late 1940s after NY 270 was truncated to begin at NY 263 in Getzville.^[12][13] Similarly, NY 270 initially overlapped with NY 93 along Junction Road from Lower Mountain Road to US 104. At Lower Mountain Road, NY 93 left NY 270 and proceeded east toward Lockport on Lower Mountain and Gothic Hill Roads.^[10][11] NY 270 was truncated to the southern end of the overlap c. 1963.^[14][15]

In the late 1970s, NY 93 was realigned to use Junction and Upper Mountain Roads instead. As a result, NY 270 was cut back to its junction with Upper Mountain Road.^[16][17] On November 1, 2005, the Niagara County Legislature voted on a measure that, if passed, would allow the county to ask the New York State Department of Transportation (NYSDOT) to remove the NY 93 designation from Upper Mountain Road, a county-maintained highway, and reassign it to Junction Road (NY 270) and Saunders Settlement Road (NY 31).^[18][19] The change was intended to eliminate truck traffic on Upper Mountain Road while providing additional capacity to NY 93.^[20] This part of the agenda was passed.^[19] NYSDOT obliged to the request in 2006,^[20] rerouting NY 93 as proposed and truncating NY 270 southward to NY 31.^[21]

Other developments

On December 1, 2008, the bridge carrying NY 270 over Tonawanda Creek (also the Erie Canal) was closed to traffic to allow construction to begin on a replacement bridge over the creek.^[22] The existing bridge was built in 1941 and considered to be structurally deficient.^[23] During construction, commuter traffic was detoured onto Tonawanda Creek and Bear Ridge Roads while trucks were instructed to follow NY 263, NY 78, and NY 93 around the closed bridge. The new bridge was opened to traffic in July 2009.^[22] NY 270's intersections with Tonawanda Creek Road (Erie CR 2) and Tonawanda Creek Road North (Niagara CR 60) on the north and south approaches to the bridge were reconstructed as part of the $10.9 million project. The new bridge is similar to the former, two-lane structure; however, unlike the old one, it has wide shoulders for bicyclists and includes new sidewalks for pedestrians.^[24]