Principal signs (本標識, hon-hyōshiki) are categorized into 4 types; guide, warning, regulatory and instruction signs.

Guide signs edit

Guide signs (案内標識, an'nai-hyōshiki) indicates directions or distances of the road. Guide signs have dark green backgrounds and white text for expressways. In urban areas and on national highways, direction signs have dark blue backgrounds. The signs are normally written in Japanese and English. Since 2014, Vialog is used as the typeface for English words and Place name Transcriptions.

^[3]

•  
  Expressway ramp ahead
•  
  Expressway exit ahead
•  
  Exits and distance (expressway)
•  
  Junction (expressway)
•  
  Expressway number (E1; Tomei)
•  
  Expressway shield (E4; Tōhoku)
•  
  Urban Expressway shield (C1; Shuto C1)
•  
  Intersection
•  
  Intersection
•  
  Distance of cities and areas
•  
  National highway shield (Route 20)
•  
  National highway shield
•  
  National highway shield
•  
  Prefectural highway shield (Fukuoka Route 758)
•  
  Prefectural highway shield
•  
  Prefectural highway shield (inter-city route)
•  
  Prefectural highway shield
•  
  Prefectural highway shield (inter-city route)
•  
  Street name
•  
  Detour
•  
  Detour
•  
  Mitigated limitation of height (expressway)
•  
  Mitigated limitation of weight

Warning signs edit

Warning signs (警戒標識, keikai-hyōshiki) warn drivers of dangers or situations that they must pay attention to. Their design, black pattern and border on yellow diamond (usually with 45 cm per a side), is based on the U.S. MUTCD (due to this nation being part of Major non-NATO ally).^[4]

•  
  Crossroads
•  
  T-intersection with road on the right
•  
  T-junction
•  
  T-intersection with road on the left
•  
  Y-junction
•  
  Traffic circle
•  
  Curve to the right
•  
  Curve to the left
•  
  Sharp curve to the right
•  
  Sharp curve to the left
•  
  Double curve, first to the right
•  
  Double curve, first to the left
•  
  Double sharp, first to the right
•  
  Double sharp, first to the left
•  
  Winding road first curve to the right
•  
  Winding road first curve to the left
•  
  Railroad crossing ahead
  Option 1: steam locomotive
•  
  Railroad crossing ahead
  Option 2: electric train
•  
  School ahead
•  
  Traffic light ahead
•  
  Slippery road
•  
  Fallen rocks
•  
  Bumpy road
•  
  Traffic merges from the left
•  
  Left lane ends
•  
  Road narrows on both sides
•  
  Two-way traffic ahead
•  
  Steep descent (10%, 1:10)
•  
  Steep ascent (10%, 1:10)
•  
  Men at work
•  
  Crosswind
•  
  Watch for large animals (deer)
•  
  Watch for large animals (rabbit)
•  
  Watch for large animals (monkey)
•  
  Watch for large animals (raccoon dogs)
•  
  Be careful

Regulatory signs edit

Regulatory signs (規制標識, kisei-hyōshiki) show the regulations of each roads in order to keep road condition and prevent dangers of traffic.

The stop sign is a red, downward-pointing triangle, with the text 止まれ (tomare) & "stop" (in English, for the pre-1963 and current designs only) in white. Prohibition signs are round with white backgrounds, red borders, and blue pictograms. Mandatory instruction signs are round with blue backgrounds and white pictograms.

• Stop and slow down
•  
  Slow down (In Japanese and English, current design from 2017)
•  
  Slow down (In Japanese Only, phased out in 2017)
•  
  Yield (In Japanese Only, phased out in 2017)
•  
  Stop (In Japanese and English, current design from 2017)
•  
  Stop (In Japanese Only, used from 1963 to 2017)
•  
  Stop (In English Only, used in United States Armed Forces Bases in Japan.)
•  
  Stop sign, used from 1950 to 1960
•  
  Stop sign, used from 1960 to 1963

• Exclusions
•  
  Road closed to all
•  
  Road closed to vehicles
•  
  No entry
•  
  No motor vehicles except motorcycles and mopeds
•  
  No trucks
•  
  No buses
•  
  No motorbikes or mopeds
•  
  No non-motorized vehicles except bicycles
•  
  No bicycles
•  
  No motor vehicles
•  
  No two-person motorbikes or mopeds
•  
  No vehicles carrying dangerous goods
•  
  Weight limit
•  
  Height limit
•  
  Width limit
•  
  Motor vehicles only(Except mopeds)
•  
  Bicycles only
•  
  Bicycles and pedestrians only
•  
  Pedestrians only
•  
  Road closed to pedestrians

• Turns
•  
  Only straight ahead or left turn permitted
•  
  Only straight ahead or right turn permitted
•  
  Turn left
•  
  Turn right
•  
  No turns
•  
  Turn left or right
•  
  Directions permitted
•  
  Roundabout
•  
  Keep left
•  
  Keep right
•  
  No crossing center line to enter e.g. a car park
•  
  No U-turn
•  
  Two-stage right turn for mopeds & bicycles required.
•  
  Two-stage right turn for mopeds & bicycles NOT required.

• Restrictions
•  
  No crossing center line to overtake. 追越し禁止 sign below = NO passing at all
•  
  Speed limit
•  
  End of special speed limit
  The statutory speed limit applies
•  
  End of speed restriction limit^[5]
•  
  Minimum speed limit
•  
  One-way street to the left
•  
  One way street to the right
•  
  One-way street ahead
•  
  One way (bikes)
•  
  Trucks use left lane^[6]
•  
  Buses-only lane
•  
  Bike lane
•  
  Buses-priority lane
•  
  Lane usage
•  
  Lane usage
•  
  Lane usage
•  
  Lane usage
•  
  Use car horns
•  
  No jaywalking

• Parking and stopping
•  
  No stopping
•  
  No parking
•  
  Restricted parking
•  
  Parallel parking
•  
  Perpendicular parking
•  
  Angle parking

Instruction signs edit

Instruction signs (指示標識, shiji-hyōshiki) show points and devices on the road that drivers should pay attention.

•  
  Cyclists are permitted to ride side-by-side.
•  
  Driving on tram line permitted (Except two-wheelers)
•  
  Priority road
•  
  Center line
•  
  Stop line
•  
  Parking zone
•  
  Stopping permitted
•  
  Crosswalk
  Alt. A
•  
  Crosswalk
  Alt. B: school zone
•  
  Bike crossing
•  
  Bike and crosswalk
•  
  Tram stop
•  
  Controls ahead

Supplemental signs (補助標識, hojo-hyōshiki) are usually put just below the principal signs, and shows their valid range like time, day and category of vehicle.^[7] They are equivalent to the "plaque" of the American MUTCD. The width of the plates is usually 60 cm, and the sentences should be less than 7 characters per a line or 3 lines.^[8] When the sentences can not be shortened less than the limitation, they should apply changeable signs.^[8]

•  
  100 meters ahead
•  
  Next 50 meters
•  
  Except Sundays and Holidays
•  
  8 a.m. to 8 p.m.
•  
  Except mopeds
•  
  Large trucks
•  
  Bicycles (symbol)
•  
  Trucks (symbol)
•  
  Trucks carrying over 3 tonnes (symbol)
•  
  Only for permitted vehicles
•  
  Leave at least 6 meters road width clear when you park
•  
  Permitted until the time the parking meter shows
•  
  Restriction begins (symbol)
•  
  Restriction begins
•  
  Restriction begins
•  
  Restricted zone (symbol)
•  
  Restricted zone
•  
  End of restriction (symbol)
•  
  End of restriction
•  
  End of restriction
•  
  End of restriction
•  
  School zone
•  
  No passing or overtaking
•  
  Yield
•  
  Train crossing caution
•  
  Caution crosswind
•  
  Caution wild animals
•  
  Caution
•  
  Safety speed: 30 km/h
•  
  Caution soft shoulder
•  
  Be quiet
•  
  direction
•  
  Control zone: Honmachi, Komoro
•  
  Starts
•  
  Ends

•  
  Expressway name (Tomei)
•  
  Asian Highway route shield (AH1)
•  
  Ferry (pictogram established in Japanese Industrial Standards)

The first standardised road signage schemes appeared in 1922. At first, two types of signs were established: "road warning signs" equivalent to warning signs and "road guide signs" as information signs.^[9] Warning signs at that time closely resembled the British design as used in Hong Kong, the only difference was the white-on-black lettering.

Japanese road signs in the early 1940s closely followed European road signage practices at that time based on the 1931 Geneva Convention, except that most road signages contained text. A variation of the early 1940s Japanese road signage system is still in use today in Taiwan.^[9][10]

In 1950, a complete revision of the "Road Signs Ordinance" was promulgated and enforced as an Ordinance of the Prime Minister's Office and the Ministry of Construction. Unlike the 1922 and the 1940s devised road signs, it included both bilingual Japanese and English text and symbols. Warning signs were changed from a European red-bordered triangular design to an American MUTCD yellow diamond design.^[9] It also introduces the yellow American stop sign that only lasted for 10 years. This road signage system was used until 1963, when it was replaced with a new road signage system that is based on the Vienna Convention on Road Signs and Signals. The present-day Japanese road signage system also replaced the stop sign's shape with an inverted equilateral triangle like the old stop sign used in China.^[9]

In 2016, it was announced that the Japanese National Police Agency was considering changing the design of the "Stop" sign used on Japanese roads since 1963 from the inverted red triangle sign to an octagonal design more closely conforming to the recommendations of the 1968 Vienna Convention on Road Signs and Signals.^[11] The inverted red triangle sign was introduced in 1963 ahead of the 1964 Summer Olympic Games in Tokyo, and replaced the earlier red octagonal sign used from 1960, which in turn had replaced the yellow octagonal sign used from 1950.^[11] It was later decided to make the stop sign bilingual in both Japanese and English, but to maintain the inverted triangular shape.^[12]

•  
  Street name and highway shields (Chiba Prefecture)
•  
  Expressway exit sign
•  
  Intersection guide sign
•  
  Height and weight restrictions apply (to streets pointed to by arrows)
•  
  Lane usage signs
•  
  Changeable lane usage signs
•  
  Directions permitted
•  
  Tram stop
•  
  Right turn prohibition (7-9 a.m.) ends
•  
  Taxis without any passengers can not enter from 9 p.m. until 2 a.m.
•  
  Restrictions 200 m ahead
•  
  Asian highway sign and symbol of Nihonbashi (Shuto Expressway)

• 時崎賢二 (1979). "道路標識等の基礎知識". 月刊交通. 10 (5). 東京法令出版: 18–29.
• 時崎賢二 (1990). "道路標識の国際化". 月刊交通. 21 (4). 東京法令出版: 19–39.
• dark-RX (2008-03-20). "見つけよう! 旧標識". 酷道をゆく. イカロス出版: 104–107. ISBN 978-4-86320-025-8.
• 全国道路標識標示業協会（編） (2013). 道路標識ハンドブック (2012年度版 ed.). 全国道路標識・標示業協会.
• 警察庁交通局 (2017-04-24). "交通規制基準" (PDF). 警察庁. Retrieved 2017-11-08.
• "道路標識、区画線及び道路標示に関する命令　別表第２". www.mlit.go.jp. Retrieved 2018-01-24.
• "17062814_ichiran（止まれ、徐行正式版追加）" (PDF). www.mlit.go.jp (PDF). 2017-06-28. Retrieved 2018-01-25.