Interstate Highway standards in the context of "Waiver"

Interstate 80 (I-80) is a transcontinental Interstate Highway in the United States, stretching from San Francisco, California, to Teaneck, New Jersey. The segment of I-80 in California runs east from San Francisco across the San Francisco–Oakland Bay Bridge to Oakland, where it turns north and crosses the Carquinez Bridge before turning back northeast through the Sacramento Valley. I-80 then traverses the Sierra Nevada, cresting at Donner Summit, before crossing into the state of Nevada within the Truckee River Canyon. The speed limit is at most 65 mph (105 km/h) along the entire route instead of the state's maximum of 70 mph (110 km/h) as most of the route is in either urban areas or mountainous terrain. I-80 has portions designated as the Eastshore Freeway and Alan S. Hart Freeway.

Throughout California, I-80 was built along the corridor of US Route 40 (US 40), eventually replacing this designation entirely. The prior US 40 corridor itself was built along several historic corridors in California, notably the California Trail and Lincoln Highway. The route has changed from the original plans in San Francisco due to freeway revolts canceling segments of the originally planned alignment. Similarly in Sacramento, the freeway was rerouted around the city after plans to upgrade the original grandfathered route through the city to Interstate Highway standards were canceled.

Interstate 278 (I-278) is an auxiliary Interstate Highway in New Jersey and New York in the United States. The road runs 35.62 miles (57.32 km) from US Route 1/9 (US 1/9) in Linden, New Jersey, northeast to the Bruckner Interchange in the New York City borough of the Bronx. The majority of I-278 is in New York City, where it serves as a partial beltway and passes through all five of the city's boroughs. I-278 follows several freeways, including the Union Freeway in Union County, New Jersey; the Staten Island Expressway (SIE) across Staten Island; the Gowanus Expressway in southern Brooklyn; the Brooklyn–Queens Expressway (BQE) across Northern Brooklyn and Queens; a small part of the Grand Central Parkway in Queens; and a part of the Bruckner Expressway in the Bronx. I-278 also crosses multiple bridges, including the Goethals, Verrazzano–Narrows, Kosciuszko, and Robert F. Kennedy bridges.

I-278 was opened in pieces from the 1930s through the 1960s. Some of its completed segments predated the Interstate Highway System and are thus not up to standards, and portions of I-278 have been upgraded over the years. In New York, the various parts of I-278 were planned by Robert Moses, an urban planner in New York City. The segments proposed tore through many New York City neighborhoods, causing controversy. Despite its number, I-278 does not connect to I-78. There were once plans to extend I-278 west to I-78 east of the Route 24 interchange in Springfield, New Jersey. This was canceled because of opposition from the communities along the route. The segment that does exist in New Jersey was opened in 1969. There were also plans to extend I-78 east across Manhattan and into Brooklyn via the Williamsburg Bridge; this would have been a second interchange between I-278 and its parent highway, but these plans were also thwarted. I-78 was also planned to extend east beyond I-278 to John F. Kennedy International Airport, and then curve northward on the Clearview Expressway, ending at the Bruckner Interchange in the Bronx. If these plans were fully completed, I-78 and I-278 would have met at three interchanges.

Interstate 26 (I-26) is a main route of the Interstate Highway System in the Southeastern United States. Nominally east–west, as indicated by its even number, I-26 runs from the junction of US Route 11W (US 11W) and US 23 in Kingsport, Tennessee, generally southeastward to US 17 in Charleston, South Carolina. The portion from Mars Hill, North Carolina, east (compass south) to I-240 in Asheville, North Carolina, has signs indicating FUTURE I-26, because the highway does not yet meet all of the Interstate Highway standards.

Northward from Kingsport, US 23 continues to Portsmouth, Ohio, as Corridor B of the Appalachian Development Highway System, and beyond to Columbus, Ohio, as Corridor C. In conjunction with the Columbus–Toledo corridor in Ohio formed by I-75, US 23, and State Route 15 (SR 15), I-26 forms part of a mostly high-speed four-or-more-lane highway from the Great Lakes to the Atlantic Coast at Charleston, South Carolina.

Auxiliary Interstate Highways (also called three-digit Interstate Highways) are a subset of highways within the United States' Interstate Highway System. The 323 auxiliary routes generally fall into three types: spur routes, which connect to or intersect the parent route at one end; bypasses, which connect to the parent route at both ends; and beltways, which form a circle that intersects the parent route at two locations. Some routes connect to the parent route at one end but to another route at the other end; some states treat these as spurs while others treat them as bypasses. Like the primary Interstate Highways, auxiliary highways meet Interstate Highway standards (with rare exceptions).

The shorter auxiliary routes branch from primary routes; their numbers are based on the parent route's number. All of the supplement routes for Interstate 95 (I-95) are designated with a three-digit number ending in "95": I-x95. With some exceptions, spur routes are numbered with an odd hundreds digit (such as I-395), while bypasses and beltways are numbered with an even hundreds digit (such as I-695). Because longer Interstates may have many such supplemental routes, the numbers can repeat from state to state along their route, but they will not repeat within a state.