The following highways are numbered 23A:
New York State Route 32A (NY 32A) is a state highway in the Hudson Valley region of New York in the United States. It serves as a connector between NY 32 in the town of Saugerties and NY 23A in the town of Catskill. The road allows traffic from the Saugerties area, particularly from the New York State Thruway, to directly reach the interior of the Greene County portion of Catskill Park. The majority of traffic is tourism-oriented, from hikers in summer to skiers bound for Hunter Mountain in winter. If NY 32A did not exist, drivers would have to go several miles out of their way to the intersection of NY 32 and NY 23A.
Maryland Route 23 is a state highway in the U.S. state of Maryland. The state highway runs 20.58 miles (33.12 km) from U.S. Route 1 in Hickory north and west to the Pennsylvania state line near Norrisville, where the highway continues as Pennsylvania Route 24. MD 23 is an L-shaped highway in northwestern Harford County that consists of two major sections. Between US 1 and MD 165 in Jarrettsville, MD 23 is marked east–west along a two-lane road with partial control of access named East–West Highway. From MD 165 to the state line, the state highway is marked north–south along Norrisville Road, a rural two-lane highway that passes through the villages of Madonna and Shawsville. The two sections of MD 23 are connected by a short concurrency with MD 165.
New York State Route 23A (NY 23A) is an east–west state highway in Greene County, New York, in the United States. It serves as a 34.56-mile (55.62 km) alternate route of NY 23 through the northern Catskill Mountains. The route passes several of the Catskill High Peaks, including Hunter Mountain, before dropping into the Hudson Valley via Kaaterskill Clove and ending at an intersection with U.S. Route 9W (US 9W) in the village of Catskill. NY 23A was assigned in the mid-1920s and has not been changed since. A portion of the route through Kaaterskill Clove was closed for several months in 2006 after landslides triggered by heavy rains damaged the route.
New York State Route 296 (NY 296) is a 7.90-mile (12.71 km) north–south state highway located entirely within both the Catskill Park and Greene County, New York, in the United States. It connects NY 23A in the village of Hunter with NY 23 near the Windham hamlet of Hensonville. The route follows a mountainous track between the two locations, climbing up from the Schoharie Creek valley before descending again into the Batavia Kill watershed. NY 296 was assigned as part of the 1930 renumbering of state highways in New York; however, the highway had been state-maintained since the early 1910s.
U.S. Route 23 (US 23) in North Carolina is a north–south United States Numbered Highway that runs for 106 miles (171 km) from the Georgia state line, near Dillard, to the Tennessee state line, near Flag Pond.