Iran route numbering system
Iran route numbering system is a network of highways and roads in Iran that is managed by Iran Road Maintenance & Transportation Organization. The network comprises main highways and several major and minor country roads. History. Probably in the late 1990s, all road numbers were changed. The old system was also a grid, but with only 5 east-west routes (even numbers 2-10) and only 7 north-south routes (odd numbers 1-13). Therefore, the new system is a lot denser, though there are a few sections that used to have a number that is not  numbered anymore. Route signs. blue on motorways, green on other roads. 3-digit numbers appear in black on a white rectangle Routes. Motorway (Freeway). Numbers roughly increase from west to east . National highway. Odd numbers (11-99) generally denote north-south routes, while even numbers (12-98) denote east-west routes. Numbers increase in eastbound and southbound direction respectively. There are some A roads without a national number. Motorways do not have national numbers. 3-digit numbers are derived from 2-digit numbers by adding a digit at the end.