Route number

The numbers chosen may be used solely for internal administrative purposes; however, in most cases they are also displayed on roadside signage and indicated on maps.

For instance, among A1 motorways, the one in Spain has a hyphen between the A and the 1 (Autovia A-1) while in Germany the Autobahn 1 is written A 1, with a space between the A and the 1.

[4] Alphanumeric routes have been introduced in most states and territories in Australia, partially or completely replacing the previous systems.

[5] In 1955, the Australian National Route Numbering System was introduced to simplify navigation across Australia.

National Route 1 was assigned to a network of highways and roads, which together linked all capital cities and coastal towns circumnavigating the mainland.

[11] In the 1990s in Sydney and Brisbane, urban route numbering system were streamlined under the Metroad scheme.

The new system aimed to upgrade the signing of destinations, including previously unmarked roads, and to simplify navigation by allowing visitors to follow numbered routes.

New alphanumeric numbers are appearing for other new roads, and cover plates for signs, possibly pointing to a future phase-out of the metropolitan route system altogether.)

The National Highways were retained, but with the route numbers changed to alphanumeric designations (later to be passively phased out since 2014).

New South Wales and the Australian Capital Territory[a] introduced the alphanumeric system from early 2013.

One of six letters may be used: Bulgaria uses prefix A for highways A1–A7 and Roman numerals I, II, III (followed by a hyphen) for the first-, second- and third-class roads.

Odd numbers refer to routes that are generally perpendicular to the Saint Lawrence River.

National expressways of China are designated with letter G (for 国家高速, guójiā gāosù) followed by 1, 2, or 4 digits.

Provincial expressways are designated with letter S (for 省高速, shěng gāosù) followed by 1 or 2 digits.

Similar to the national expressways, one-digit numbers are used for routes starting in the provincial capital.

Since 2017, the Chinese route naming standard no longer designates provincial expressways with 4 digit numbers.

On directional traffic signs, identification plates of bridge objects or in maps, the route number is given without a prefix.

In texts, official decisions and announcements, the route number is usually preceded by a class designation with a slash (I/67, II/102, III/00425).

The prefix D is derived from the word "dálnice/dialnica", which is abbreviation of "long-distance road", the substantive "dálka" means "a (long) distance".

Markings with the R prefix for "expressways" (rychlostní silnice, the word "rychlost" means "a velocity") were also used in the road network maps and strategic documents.

R-roads did not have a separate numbering system, but they were sections of ordinary I-class roads, but in construction parameters and with a traffic regime similar to highways.

The main change was that most sections of R-roads (expressways) were recategorized to highways and the R prefix has fallen into disuse for the remaining ones as well.

On the roads, cycling routes are marked with specific official orange-black directional road signs, and for local and off-road routes, stripe marks derived from Czech Hiking Markers System are used (with orange margin stripes instead of white ones).

The classification and numbering system of state-maintained roads of Finland is as follows: Streets are maintained by the local municipality.

The numbers of motorways and tunnels are assigned with a circular from the Minister of Infrastructure and Transport to be published in the Gazzetta Ufficiale.

Instead, expressways in Singapore are assigned a three letter code, such as ECP for East Coast Parkway.

[citation needed] A similar clock-face zonal system is used in many other European countries (for example, Spain and Belgium).

U.S. Route 66, known as the "Mother Road", was a cultural touchstone that inspired literature, songs, and other media from its creation in 1926 until it was superseded by segments of the Interstate Highway System.

The designations, depicted with a green rectangle with white numbers and letters, are used on guide signs as well as highway shields.

Where a highway changes into a motorway or vice versa, it may continue to use the same number, but the letter and the color are switched.