Speed limitThailand
2. Speed limit
A speed limit is the maximum legal speed permitted on a road, lane or within a designated area. It may be established by general traffic law or indicated by fixed, variable or temporary traffic signs.
A speed limit is a maximum, not a target speed. Drivers must travel more slowly whenever traffic, visibility, weather, road conditions, vulnerable road users or the condition of the vehicle make the maximum permitted speed unsafe.
Wikimedia.org • Thaweesak Churasri • CC BY
Which general speed limits should car drivers know in Thailand?
For an ordinary car, the national framework generally allows 80 km/h in specified urban areas and 90 km/h elsewhere, with separate categories and regulations for divided roads, expressways and motorways. Selected qualifying highways permit up to 120 km/h. Local rules can be substantially lower, including Bangkok’s general 60 km/h restriction with specified road exceptions. Follow the applicable signs and local conditions.
🔗 infocenter.oic.go.th • OIC official summary — 2021 speed frameworks and vehicle/road categories
🔗 upload.wikimedia.org • Royal Gazette facsimile of full 2021 general speed Regulation, mirrored PDF
🔗 ratchakitcha.soc.go.th • Royal Gazette — full December 2024 Bangkok speed and horn order
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.
Does every divided Thai highway allow 120 km/h?
No. The 120 km/h arrangement applies only to qualifying, designated national or rural highway sections with at least two lanes in the same direction, a barrier median and no at-grade U-turn points. The competent highway director must designate the section. A central reservation or two lanes alone is insufficient. Follow the vehicle-category rules and applicable lower signs.
🔗 infocenter.oic.go.th • OIC official summary — 2021 speed frameworks and vehicle/road categories
🔗 upload.wikimedia.org • Royal Gazette facsimile of full 2021 general speed Regulation, mirrored PDF
🔗 ratchakitcha.soc.go.th • Royal Gazette — full December 2024 Bangkok speed and horn order

Traffic rules
Thailand