signaling traffic destined for the towns of
Sigurd and
Aurora to exit the freeway. The road at this exit is officially designated
SR 259, a short connector; however, the sign instead shows
SR 24, the highway at the other end of the connector.
Highway maintenance agencies with multiple numbering systems • The C, D, and U road systems in the
Great Britain road numbering scheme are systems of routes considered less important than B roads and typically left unsigned •
Delaware,
New York, and
Pennsylvania, among other jurisdictions, sign virtually all state maintained transportation features with small inventory markers, called
maintenance road numbers (reference numbers),
reference routes, and
Quadrant Routes respectively. •
Secondary highways in states such as
Montana are often unsigned (or minimally signed) when they pass through city or urban limits.
Signed with a name and not a number •
Queen Elizabeth Way (Highway 451) in
Ontario •
Skyline Drive and
Blue Ridge Parkway (
State Route 48) in
Virginia •
Florida's Turnpike (State Road 91) in
Florida •
Canal Parkway (State Route 61) in Maryland • Several parkways and toll roads in
New Jersey, including:
Garden State Parkway (Route 444), southern portion of the
New Jersey Turnpike (Route 700), the
Palisades Interstate Parkway (Route 445 in New Jersey) and the
Atlantic City Expressway (Route 446). • The
Kentucky parkway system of former toll roads were initially signed exclusively with their names, although all carry an unsigned designation over 9000.
Concurrencies in
Bowie, Maryland. The empty spaces next to the US 50 shields were reserved for
Interstate 595 shields, which US 50 is concurrent with. However, the shields were never added, and I-595 remains unsigned. There are numerous cases in the United States where the same physical roadbed has designations in the
Interstate Highway System,
U.S. Highway system and the state route system. In many cases one or more of the official designations is omitted. • Many examples exist in the
western United States where an Interstate highway runs concurrent with a U.S. or state highway, but only the Interstate designation is signed, though any route that becomes unsigned in these situations will still be signed on many road maps and atlases. Examples include
U.S. Route 6 which is unsigned while concurrent with
Interstate 70 throughout
Colorado and
U.S. Route 77 with
Interstate 35E through the
Dallas metropolitan area. • Conversely, there are
several urban freeways in the U.S. that have an unsigned Interstate Highway designation. Examples include:
Interstate 444 in
Tulsa,
Oklahoma,
Interstate 345 in
Dallas,
Texas,
Interstate 305 in
Sacramento,
California, and
Interstate 595 in
Maryland. • The Interstate Highway System includes highways outside the
contiguous United States. While the ones in
Hawaii are signed similar to those in the contiguous United States, those in
Alaska and
Puerto Rico are signed with their state/territory route designation, not Interstate Highway shields. • In the states of
Alabama,
Florida, and
Tennessee, every US Highway is concurrent with an unsigned state highway for its entire length. Similarly, in the states of Florida and
Georgia, every Interstate Highway is concurrent with an unsigned state highway for its entire length. In Tennessee, the state highway route number is signed along the green mile marker signs that display mileage within each county.
Other situations • There are a small number of cases where a highway briefly crosses a political boundary, but is only signed with its designation on one side of that political boundary. Examples include the
Alaska Highway, which crosses the boundary of the Canadian provinces of
British Columbia and
Yukon Territory several times. Although the highway has different numbered designations on each side of the border, the signs along it change designation at only one point. Another example is
Washington State Route 41, the unsigned designation for a brief portion of the highway signed
Idaho State Highway 41 that crosses the state line. • The
East Los Angeles Interchange is a case where a highway is unsigned with a conflict between the state and federal definition of a highway. The state definition of
Interstate 10 has a discontinuity with a stub freeway proceeding west from the northern part of this interchange towards
U.S. Route 101, while the federal definition of I-10 is contiguous. The discrepancy is resolved by having westbound signage at the interchange follow the federal definition. When driving west, I-10 is signed proceeding towards the main portion of the interchange concurrent with
I-5, while the I-10 stub is signed instead as US 101. ==References==