Every time you drive through an intersection, a curve, or a construction zone — traffic signs are the direct communication between road designers and drivers. But to understand all traffic signs, you need to know what each color and shape means. And when you need to order or install them — choose the correct film grade and material from the start.
How many types of traffic signs are there? — 4 main types according to Thai law
All traffic signs in Thailand are divided into 4 main types based on their communication characteristics, shapes, and colors as specified in the Department of Highways standard — each type has a clear and distinct role:
Shape: Red circle, diagonal line or prohibition symbol · Violation punishable by fine
Signs with legal effect, such as no entry, no parking, speed limit, stop.
Examples: Stop sign · No entry · No overtaking · 80 km/hShape: Diamond shape, yellow background · Not prohibitive, but requires caution
Informs of upcoming hazards — drivers must slow down and exercise increased caution.
Examples: Curve ahead · Slippery road · Children crossing · Narrow roadShape: Rectangular, blue or green background · Non-binding
Provides information to assist travel, showing place names, distances, and directions.
Examples: Direction sign · Distance sign · Exit sign · Road nameShape: Square, orange background · Temporary
Used in construction or road repair areas. Must be clearly visible day and night.
Examples: Road work ahead · Detour · Workers aheadYellow traffic signs — The most common warning signs on the road
Yellow traffic signs, or warning signs, are the most common signs found on rural roads in Thailand because secondary roads have various dangerous points — sharp curves, intersections, slippery roads, or children crossing. Every such point requires a warning sign at least 100–150 meters in advance.
The diamond shape (rotated 45°) was chosen because it does not overlap with other shapes in the traffic sign system, allowing drivers to distinguish it immediately even from a distance or in poor visibility conditions.
Guide Signs and Direction Signs
Guide Signs are divided into 2 main types based on their guiding nature — guide signs that provide information about places and distances, and direction signs that directly indicate directions with arrows at the end of the sign.
Presents information about places, destinations, and directional arrows. Often includes distance or symbols. Should be installed 25–150 meters before the intersection, according to traffic standards.
The end of the sign is a direct arrow pointing the way. Indicates the distance from the intersection to the location in meters or kilometers. Government signs use a white background with black text. Private signs can use brand colors.
3 Grades of Reflective Film — Determines "how far a sign can be seen"
A good traffic sign is not just measured by how beautifully it's printed — but by the visible distance at night, which depends on the grade of reflective film coated on the aluminum sheet.
| Film Grade | Visible Distance | Lifespan | Suitable for | Price |
|---|---|---|---|---|
| Engineer Grade (EG) | 100–150 m | 3–5 years | Soi, Villages, Construction sites | Most economical |
| High-Intensity Prismatic (HIPS) | 200–300 m | 7–10 years | City roads, Intersections | Medium |
| Diamond Grade (DG) — 3M | 400+ m | 10–12 years | Highways, Motorways | 3–4× higher than EG |
The Department of Highways specifies that Highways No. 1–9 and motorways must use at least Diamond Grade. HIPS can be used on city roads, while EG is sufficient for small streets (soi) or private projects.
Laws and Permit Requirements for Installing Traffic Signs
A common question from customers is, "Do I need permission from anyone to install traffic signs on private roads?" The answer depends on the area:
Private projects / Village roads / Factories
No permit required, can be installed immediately — signs in private areas are at the owner's discretion.
Municipal roads / Provincial roads
Obtain permission from the responsible municipality or Subdistrict Administrative Organization. Takes approximately 2–4 weeks.
National Highways (No. 1–9)
Obtain permission from the Department of Highways, responsible district. Must include plans and installation locations.
Roads in Bangkok Metropolitan Area (BMA)
Obtain permission from the BMA's Department of Traffic and Transport or the responsible district office.
How to choose the right type and grade of traffic sign
Before ordering traffic signs, answer these 3 questions:
What do you want to communicate — prohibition, warning, or guidance?
Prohibition = red circle · Warning = yellow diamond · Guidance = blue/green rectangle · Construction = orange
How fast is the traffic — Determines film grade
≤60 km/h → EG · 60–100 km/h → HIPS · More than 100 km/h → Diamond Grade
Permanent or temporary installation — Determines material
Permanent → 2–3 mm aluminum + reflective film · Temporary → PVC or thin aluminum with foldable pole
Traffic Signs and Safety Signs Products from Octopus
Octopus manufactures all types of traffic and safety signs — from standard Department of Highways traffic signs to prohibition and safety signs for factories and buildings:
Reflective Aluminum Traffic Signs
EG / HIPS / Diamond Grade 3M according to Department of Highways standards
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Prohibition Signs ISO 7010
No smoking, No parking, No entry, 80+ designs
View Products →Warning Signs, Safety Signs
ISO 7010 — Electrical warning, Chemical hazard, PPE, Factory signs
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Parking Signs
Parking, No Parking, No Parking Anytime, Valet
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Wayfinding Signs
Indoor navigation, Exit, Entrance, Hanging signs
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Fire Exit Signs
Photoluminescent / LED, TIS standard
View Products →Need traffic signs or safety signs?
Tell us the installation location, road type, and quantity.
The Octopus team will recommend the appropriate film grade, assist with permits, and provide full production and installation services.