A fictional road number is a road number that does not really exist except in works of fiction.

United Kingdom

If a fictional road number is used in on TV or film, it is blacklisted, meaning it cannot be used in real life for five years.

• The Archers, a BBC radio soap opera
  Note: These road numbers were obtained from the map of Borsetshire provided by the BBC. [1] Since the county is apparently between Worcestershire and Warwickshire, the numbers in the county should technically begin with a 4 to be in the right "zone", according to the British road numbering scheme.
  • A1702
  • A1823
  • A1829
  • A1835
  • A1992
  • A9110, linking the town of Borchester with the city of Felpersham
  • B1900
  • B1985
  • B3391, running through the village of Ambridge where the series is set
  • B3700
  • B3770
  • B4879
• Blott on the Landscape
  • M101, featured in the novel by Tom Sharpe
  • M399, featured in the 1985 TV version instead of the M101
• Thunderbird 6
  • M104, used in the 1966 film - in reality, this was part of the M40 motorway that had just been built and not yet opened

United States

• Interstate 60, featured in the 2002 film of the same name, directed by Bob Gale
• Interstate 570, a new freeway that is built in a fictional script for South Park [2]
• Highway 8, runs through the town of Hill Valley in the Back to the Future films
• Highway 395, also runs through the town of Hill Valley in the Back to the Future films
• Route 401, runs through the town of Springfield in the TV series The Simpsons
• Skyway C25, seen in the year 2015 in the film Back to the Future Part II (1989)