Japan | Area code 81 | Common abbreviation J | Last updated 5-1-2008 |
| Road class | Syntax explanation | Administrative subordination | Sub classes | Zones | System | Remarks |
| National highway | [0-9]<1-3> | national | 1-d | | sequential | sequential exit numbers |
| 2-d | | |
| 3-d | | |
| Expressway | [0-9]<1-2> | Tokyo, Nagoya, Osaka/Kobe | | | sequential | |
| Local road | [0-9]<1-3> | prefecture | | | sequential |
General description: Motorways are usually not numbered, except for urban expressways. They have names (Jidoshi-do), e.g. Kanetsu Jidoshi-do, Tohoku Jidoshi-do.
National highways 1-58 are the most important roads, see Route list.
Numbers are assigned sequentially, mostly beginning in the northeast (on the main island) and increasing towards the
southwest, and then in Hokkaido. Then numbering starts on the main island again etc.
There are 5 ranges on the main island and 4 on Hokkaido for 1- and 2-d numbers and 6 on the main island and 5 on Hokkaido for 3-d numbers. The 1- and 2-d ranges on Hokkaido consist of only one number except for 36-40.
On the main island, ranges always increase towards the southwest (except for the first few) but on Hokkaido they sometimes increase to the northeast.
The table below shows how all number ranges are distributed. The Main area includes all islands except Hokkaido.
Two exceptions are the numbers 250 and 251, which are much too far to the west to fit into the system.
|
| numbers | Main area | direction of increase | numbers | Hokkaido | direction of increase |
| 1- and 2-d numbers |
| 1-4 | from Tokyo | - | 5 | Hakodate-Sapporo | - |
| 6-11 | from Tokyo | - | 12 | Sapporo-Asahikawa | - |
| 13-35 | Akita-Sasebo | N-S | 36-40 | Sapporo-Wakkanai | S-N |
| 41-43 | Nagoya-Kobe | N-S | 44 | Kushiro-Nemuro | - |
| 45-58 | Aomori-Okinawa | N-S | |
| 3-d numbers |
| 101-226 | Aomori-Kagoshima | N-S | 227-244 | Hakodate-Abashiri | S-N |
| 245-270 | Mito-Kagoshima | N-S | 272-278 | Kushiro-Hakodate | N-S |
| 279-332 | Aomori-Okinawa | N-S | 333-337 | Abashiri-Sapporo | N-S |
| 338-390 | Aomori-Okinawa | N-S | 391-393 | Abashiri-Sapporo | N-S |
| 394-449 | Aomori-Okinawa | N-S | 451-453 | Takikawa-Sapporo | N-S |
| 454-507 | Aomori-Okinawa | N-S | |
| Remark: numbers 271 and 450 may exist as well. |
| Numbered Expressways exist only in the three major urban areas of Tokyo, Nagoya and Osaka/Kobe. In Nagoya there are only
1-digit numbers. The highest known number is 31 in Kobe. |
| Local roads are apparently numbered per prefecture.
|
| Road signs: blue with white text. National numbers appear in a white rounded triangle and local roads in a hexagon. |
| National highway | 
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| Local road | 
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| Tokyo expressway | 
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| History: Until the 1950's, the road network was not very well developed. The first motorway was opened in 1963. |
Sources and links: various maps and atlases
Official sites:
- Japan Highway Public Corporation
- Ministry of Land, Infrastructure and Transport
Other links:
- Motorways in Japan
- Motorways in Tokyo
- Japanese Expressways
- Metropolitan Expressways
- Tokyo Expressways map
- Hanshin Expressway
- Some road pictures
- Trafficsignal pictures and other road information
Other pages within this site:
- Main national highways and Tokyo expressways route list
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