Advisory speedThailand
4. Advisory speed
An advisory speed is a recommended speed for a particular road section or hazard rather than a legally imposed maximum speed. It may be shown near bends, junctions, steep gradients, roadworks or other locations where a lower speed can help drivers negotiate the road safely.
Drivers should treat an advisory speed as guidance for safe driving conditions and should travel even more slowly when weather, visibility, traffic or road conditions require it. A separate legally binding speed limit must still be obeyed.
Wikimedia.org • CEphoto, Uwe Aranas • CC BY-SA
Is Thailand’s designated 120 km/h highway arrangement advisory?
No. The qualifying designated-highway arrangement establishes restrictions for particular vehicle classes and lanes, including a maximum for ordinary cars. Do not confuse it with recommended-speed guidance or apply it to every divided highway.
🔗 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
Can a speed recommendation override a lower restriction in Thailand?
No. A recommendation must be read within the applicable legal maximum. Lower signed, vehicle-specific or temporary restrictions still govern. Use the rule for the actual road and vehicle rather than treating a recommended number as permission to exceed it.
🔗 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
May I drive below a recommended speed when conditions worsen in Thailand?
Yes. A recommendation is not a guarantee that the speed is safe for your vehicle or the conditions. Slow for limited visibility, poor grip, traffic or another hazard, and keep enough space to stop safely. Apply any specific legal minimum together with its traffic and safety exceptions.
🔗 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