Prohibitory signsThailand

An introduction to the traffic rules and road signs of Thailand. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.


Prohibitory signs

A prohibitory sign is a traffic sign that tells drivers what is not allowed on that specific road or in that situation. These signs impose restrictions such as no entry, no overtaking, no parking, speed limits, or bans on certain types of vehicles. Their purpose is to clearly indicate actions that are forbidden to ensure safety, maintain traffic flow, and protect vulnerable road users.


No entry. Trucks prohibited. Vehicles higher than indicated prohibited. Road narrowing, give way to oncoming drivers. Turning left prohibited. Turning right prohibited. Turning around prohibited (U-turn). Overtaking prohibited. Start of a speed limit. Entry prohibited (checkpoint). Parking prohibited. Parking and stopping prohibited.
How are prohibitory signs classified in Thailand?

Regulatory signs can require road users to refrain from an action or comply with a restriction.

🔗 network.doh.go.th • Thailand — 2020 highway-sign Regulation, actual signs/markings and separate controls

🔗 laksong.metro.police.go.th • Official Police-hosted Gazette — full enacted Road Traffic Act amendment 13, 2022

🔗 aipalync.org • Council of State Thai Act consolidation through amendment 12 — read with full amendment 13

What does a no-turn sign prohibit in Thailand?

It prohibits the left, right or other turn shown at the junction or position controlled by the sign in Thailand. Follow any supplementary panel or authorised direction and choose another legal route.

🔗 network.doh.go.th • Thailand — 2020 highway-sign Regulation, actual signs/markings and separate controls

🔗 laksong.metro.police.go.th • Official Police-hosted Gazette — full enacted Road Traffic Act amendment 13, 2022

🔗 aipalync.org • Council of State Thai Act consolidation through amendment 12 — read with full amendment 13

Can a no-turn restriction apply only to certain vehicles or hours in Thailand?

Yes, where the local sign system provides a supplementary condition or exemption, such as a vehicle class, time or authorised access. Without a valid exception, comply with the prohibited movement shown.

🔗 network.doh.go.th • Thailand — 2020 highway-sign Regulation, actual signs/markings and separate controls

🔗 laksong.metro.police.go.th • Official Police-hosted Gazette — full enacted Road Traffic Act amendment 13, 2022

🔗 aipalync.org • Council of State Thai Act consolidation through amendment 12 — read with full amendment 13

1. No entry

This traffic sign means no entry. Drivers may not enter from the direction in which the sign is placed.

No entry.

English • Traffic sign บ.5 • No entry. Vehicles of any kind must not enter from the direction faced by the sign.

ไทย • บ.5 • ห้ามเข้า. ห้ามขับรถทุกชนิดเข้าไปในทางที่ติดตั้งป้ายนี้จากทิศทางที่ป้ายหันมา

Sources

🔗 Commons.wikimedia.org (Woodennature • CC BY-SA 3.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 60

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-15. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 60. Catalogue-equivalent illustration; intentional update from the previous PNG.

2. Trucks prohibited

This traffic sign indicates that trucks are prohibited. Trucks covered by the sign may not enter or continue beyond it. Any applicable weight threshold or vehicle-category limitation is determined by the sign, supplementary information and local rules.

Trucks prohibited.

English • Traffic sign บ.15 • No lorries. Lorries must not enter the signed road.

ไทย • บ.15 • ห้ามรถบรรทุก. ห้ามขับรถบรรทุกเข้าไปในทางที่ติดตั้งป้ายนี้

Sources

🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 64

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-16. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 64. Catalogue-equivalent illustration; intentional update from the previous PNG.

3. Vehicles higher than indicated prohibited

This traffic sign indicates that vehicles higher than indicated are prohibited. A vehicle or vehicle combination whose overall height, including its load, exceeds the displayed limit may not continue beyond the sign.

Vehicles higher than indicated prohibited.

English • Traffic sign บ.35 • Height limit: 4.2 m. Vehicles exceeding 4.2 m overall height including their load must not enter.

ไทย • บ.35 • จำกัดความสูง 4.2 เมตร. ห้ามรถที่มีความสูงรวมสิ่งของที่บรรทุกเกิน 4.2 เมตรเข้าไปในทางที่ติดตั้งป้าย

4. Road narrowing, give way to oncoming drivers

This traffic sign indicates a road narrowing where you must give way to oncoming traffic. Allow approaching traffic to pass before entering or continuing through the narrow section when required.

Road narrowing, give way to oncoming drivers.

English • Traffic sign บ.3 • Give way to oncoming vehicles. Stop or wait for them to pass, then proceed when clear and safe.

ไทย • บ.3 • ให้รถสวนทางมาก่อน. ให้หยุดหรือรอเพื่อให้รถที่สวนมาผ่านไปก่อน แล้วจึงเคลื่อนรถเมื่อทางว่างและปลอดภัย

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 58

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-18. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 58. Catalogue-equivalent illustration; intentional update from the previous PNG.

5. Turning left prohibited

This traffic sign indicates that turning left is prohibited. A left turn may not be made where the sign applies. Other movements may still be permitted unless another restriction applies.

Turning left prohibited.

English • Traffic sign บ.8 • No left turn. Left turns are prohibited in the controlled area.

ไทย • บ.8 • ห้ามเลี้ยวซ้าย. ห้ามเลี้ยวรถไปทางซ้ายในบริเวณที่ป้ายนี้ควบคุม

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 61

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-13. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 61. Catalogue-equivalent illustration; intentional update from the previous PNG.

6. Turning right prohibited

This traffic sign indicates that turning right is prohibited. A right turn may not be made where the sign applies. Other movements may still be permitted unless another restriction applies.

Turning right prohibited.

English • Traffic sign บ.9 • No right turn. Right turns are prohibited in the controlled area.

ไทย • บ.9 • ห้ามเลี้ยวขวา. ห้ามเลี้ยวรถไปทางขวาในบริเวณที่ป้ายนี้ควบคุม

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 61

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-13. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 61. Catalogue-equivalent illustration; intentional update from the previous PNG.

7. Turning around prohibited (U-turn)

This traffic sign indicates that turning around (making a U-turn) is prohibited. A U-turn may not be made where the prohibition applies. Other movements may still be permitted unless another restriction applies.

Turning around prohibited (U-turn).

English • Traffic sign บ.7 • No left U-turn. Leftward U-turns are prohibited in the controlled area.

ไทย • บ.7 • ห้ามกลับรถไปทางซ้าย. ห้ามกลับรถไปทางซ้ายในบริเวณที่ป้ายนี้ควบคุม

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 61

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-08. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 61. Catalogue-equivalent illustration; intentional update from the previous PNG.

8. Overtaking prohibited

This traffic sign indicates that overtaking is prohibited. The vehicles covered by the prohibition and any categories that may still be overtaken depend on the applicable local rules.

Overtaking prohibited.

English • Traffic sign บ.4 • No overtaking. Overtaking other vehicles is prohibited in the controlled area.

ไทย • บ.4 • ห้ามแซง. ห้ามขับรถแซงรถคันอื่นในเขตที่ป้ายนี้ควบคุม

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 60

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-08. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 60. Catalogue-equivalent illustration; intentional update from the previous PNG.

9. Start of a speed limit

This traffic sign indicates the start of a speed limit. The displayed value is the maximum permitted speed from this point. The limit remains in force until it ends or is replaced according to the applicable traffic signs and local rules.

Start of a speed limit.

English • Traffic sign บ.32 • Speed limit: 50 km/h. Do not exceed 50 km/h and use a speed safe for road and traffic conditions.

ไทย • บ.32 • จำกัดความเร็ว 50 กม./ชม.. ห้ามขับรถด้วยความเร็วเกิน 50 กิโลเมตรต่อชั่วโมง และต้องใช้ความเร็วที่ปลอดภัยตามสภาพทางและการจราจร

Sources

🔗 Commons.wikimedia.org
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 69

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-10. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 69. Catalogue-equivalent illustration; intentional update from the previous PNG. The catalogue depicts a variable speed value; the existing 50 km/h value is retained.

10. Entry prohibited (checkpoint)

This traffic sign indicates a checkpoint with restricted entry. Road users may not proceed beyond the checkpoint unless they are authorised or permitted to continue according to the applicable rules and instructions.

Entry prohibited (checkpoint).

English • Traffic sign บ.31 • Stop for inspection. Stop for the officials' inspection and proceed only when authorised.

ไทย • บ.31 • หยุดตรวจ. ให้หยุดรถเพื่อให้เจ้าหน้าที่ตรวจ และเคลื่อนรถต่อไปได้เมื่อได้รับอนุญาตจากเจ้าหน้าที่แล้ว

Sources

🔗 Commons.wikimedia.org
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 68

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2018-01-24. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 68. Catalogue-equivalent illustration; intentional update from the previous PNG.

11. Parking prohibited

This traffic sign indicates that parking is prohibited. Vehicles may not be parked in the area covered by the sign unless an exception applies. Brief stopping to pick up or drop off passengers or to load or unload goods may still be permitted where local rules allow it.

Parking prohibited.

English • Traffic sign บ.29 • No parking. Brief stops to pick up or set down people or goods are excepted, provided they are completed without delay.

ไทย • บ.29 • ห้ามจอดรถ. ห้ามจอดรถในเขตที่ป้ายนี้ควบคุม ยกเว้นหยุดรับส่งคนหรือสิ่งของชั่วขณะโดยต้องกระทำโดยไม่ชักช้า

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 67

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-08. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 67. Catalogue-equivalent illustration; intentional update from the previous PNG.

12. Parking and stopping prohibited

This traffic sign indicates that parking and stopping are prohibited. Vehicles may not stop or park voluntarily where the restriction applies, except where an applicable rule provides an exemption or stopping is required by traffic conditions.

Parking and stopping prohibited.

English • Traffic sign บ.30 • No stopping. Stopping or parking, including picking up or setting down people or goods, is prohibited.

ไทย • บ.30 • ห้ามหยุดรถ. ห้ามหยุดหรือจอดรถในเขตที่ป้ายนี้ควบคุม รวมถึงการรับส่งคนหรือสิ่งของ

Sources

🔗 Commons.wikimedia.org (So Monggo • CC BY-SA 4.0)
🔗 Doh.go.th • กรมทางหลวง • คู่มือ พ.ศ. 2561 • เล่ม 1 • หน้า PDF 67

SVG source: Commons.wikimedia.org • Original SVG
Government of Thailand • Public domain • Original revision 2017-11-08. Wikimedia original unmodified.

Artwork reviewed against the Thai Department of Highways 2018 catalogue: Doh.go.th • PDF page 67. Catalogue-equivalent illustration; intentional update from the previous PNG.