Gaimen50-question practice tests in the real exam formatWhat does 補助標識 (hojo hyōshiki) mean? Auxiliary signs, 8-20
Updated: 2026-10
補助標識 (ほじょひょうしき, hojo hyōshiki) is an auxiliary sign or supplemental plate, usually mounted under a main sign, that adds the times, days, vehicle types or sections a rule applies to, or the reason for it. It is a separate category from main signs (本標識: regulatory, instruction, warning and guide). Common test points: '8-20' means the rule applies from 8 a.m. to 8 p.m.; '原付を除く' means mopeds are exempt; and the difference between the abbreviations 二輪 and 自二輪.
Legal status
Article 1 of the Order on Road Signs, Lane Lines and Road Markings (道路標識、区画線及び道路標示に関する命令) divides road signs into main signs (本標識) and auxiliary signs (補助標識), and main signs into four types: guide (案内), warning (警戒), regulatory (規制) and instruction (指示). Auxiliary signs are not a fifth type of main sign.
The National Police Agency's rules explain that auxiliary signs supplement the meaning of main signs such as regulatory signs, are usually mounted below them, and show the reason for a rule or specify the times, days or vehicle types it applies to.
Main types
Some of the main auxiliary signs listed in Appended Table 3 of the rules.
| Type | Meaning |
|---|---|
| Distance, area | Distance, section or area to a regulated or dangerous place |
| Days, times | Days or hours the rule applies (e.g. 8-20) |
| Vehicle type | Which vehicles the rule covers (e.g. 大型等, 原付を除く) |
| Parking clearance | Space to leave on the right of a parked car (e.g. 6m) |
| Start, within section, within area, end | Start, section, area and end of the rule |
| No overtaking | Overtaking prohibited |
| School route, railroad crossing, crosswind, animals, caution | Reason for caution |
| Reason, notes | Reason for the rule or notes supplementing the main sign |
Vehicle-type abbreviations
To specify vehicle types, plates use the abbreviations in Appended Table 4 of the rules. Similar-looking characters are a favorite trap.
| Abbreviation | Meaning |
|---|---|
| 大型 | Large motor vehicles |
| 普通 | Ordinary motor vehicles |
| 自二輪 | Large and ordinary motorcycles (not mopeds) |
| 二輪 | Two-wheeled motor vehicles and ordinary mopeds (includes mopeds) |
| 原付 | Ordinary mopeds (一般原動機付自転車) |
| 特定原付 | Specified small mopeds (特定小型原動機付自転車) |
| 小特 | Small special motor vehicles |
How it appears on the test, and the traps
Auxiliary signs narrow or supplement the main sign. '〜を除く' removes that vehicle from the rule; a time range limits the rule to those hours.
- 'With an 8-20 plate under a no-parking sign, parking is banned from 8 a.m. to 8 p.m.' → True
- 'With a 原付を除く plate under a vehicles-prohibited sign, mopeds still may not pass' → False (mopeds may pass)
- 'Main signs are of four types: regulatory, instruction, warning and guide' → True (auxiliary signs are not main signs)
- 'If a no-crossing-right-for-overtaking sign has a 追越し禁止 plate, overtaking without crossing right is allowed' → False (all overtaking is banned)
- 'A rule for 自二輪 also applies to mopeds' → False (二輪 includes mopeds)
Practice questions using this term
FAQ
Q. Does an auxiliary sign mean anything on its own?
A. It supplements the main sign and is read together with it.
Q. What does '8-20' mean?
A. The main sign's rule applies from 8 a.m. to 8 p.m.
Q. What's the difference between 二輪 and 自二輪?
A. 二輪 covers two-wheeled motor vehicles and ordinary mopeds; 自二輪 means large and ordinary motorcycles only, not mopeds.