The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Highway System in the United States. The system extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico.
Interstate H-1 (H-1) is the longest and busiest Interstate Highway in the US state of Hawaii. The highway is located on the island of Oʻahu. Despite the number, this is an east–west highway; the 'H'-series numbering reflects the order in which routes were funded and built. H-1 goes from Route 93 in Kapolei to Route 72 in Kāhala. East of Middle Street in Honolulu (exit 19A), H-1 is also known as the Lunalilo Freeway, after the former Hawaiian king, and is sometimes signed as such at older signs in central Honolulu. West of Middle Street, H-1 is also known as the Queen Liliʻuokalani Freeway, after the former Hawaiian queen; this name is shown on some roadmaps. It is both the southernmost and westernmost signed Interstate Highway located in the US.
Interstate 585 (I-585) is a 2.25-mile-long (3.62 km) auxiliary Interstate Highway of I-85 in the US state of South Carolina. It is an orphan auxiliary route to I-85 since 1995 when the Interstate was relocated further north bypassing Spartanburg. In a concurrency with US Highway 176 (US 176) throughout, it spurs south from I-85 Business for a couple of miles before entering the downtown area.
Interstate 296 (I-296) is a part of the Interstate Highway System in the US state of Michigan. It is a north–south state trunkline highway that runs for 3.43 miles (5.52 km) entirely within the Grand Rapids area. Its termini are I-196 near downtown Grand Rapids and I-96 on the north side of Grand Rapids in Walker. For most of its length, the Interstate runs concurrently with U.S. Highway 131 (US 131), which continues as a freeway built to Interstate Highway standards north and south of the shorter I-296. The highway was first proposed in the late 1950s and opened in December 1962, but the Michigan Department of Transportation (MDOT) has since eliminated all signage for I-296 and removed the designation from their official state map. The designation is therefore unsigned, but still listed on the Interstate Highway System route log maintained by the Federal Highway Administration (FHWA).
Interstate H-201 is the only auxiliary Interstate Highway located outside the contiguous United States, serving the island of Oʻahu in the US state of Hawaii. The 4.1-mile-long (6.6 km) loop route connects exits 13 and 19 on H-1, passing Fort Shafter, Tripler Army Medical Center, and the Red Hill Underground Fuel Storage Facility.
Interstate 180 (I-180) is a 1.09-mile-long (1.75 km) expressway in the US state of Wyoming between I-80 and downtown Cheyenne.
An unsigned highway is a highway that has been assigned a route number, but does not bear road markings that would conventionally be used to identify the route with that number. Highways are left unsigned for a variety of reasons, and examples are found throughout the world. Depending on the policy of the agency that maintains the highway, and the reason for not signing the route, the route may instead be signed a different designation from its actual number, with small inventory markers for internal use, or with nothing at all.
The Roads in Puerto Rico are the national, forest and municipal roadways that make up the approximately 14,400 kilometers (8,900 mi) roads through the terrain of Puerto Rico. The highways serve the more than 3 million residents, and 3-4 million tourists who visit each year.
