Thai law tells a driver to stop the load falling off. It does not say how hard to tie it, how many straps, or how fast the truck may stop before the load moves. That gap is where loads fall off the back of trucks. This article sets out what the Thai statutes do say, and then borrows a tested method for the part they leave out.
The short answer
- Thai law gives a duty, not a number. The Road Traffic Act, Section 20, says the driver must provide protection so the load does not fall, leak, smell, reflect light or blow off. It names no force, no strap and no count.
- Two people can be fined. The driver under the traffic and transport Acts, and the operator if the vehicle lacks the fittings a Ministerial Regulation requires, up to 50,000 baht.
- For containers there is a figure. The Department of Land Transport said in 2023 that each container needs at least four securing devices, with lock-status plates.
- For everything else, use a tested standard. Australia's regulator requires a restraint system to hold 80% of the load's weight forwards and 50% sideways and rearwards. It is not Thai law, but it is a number you can write into a contract.
- Blocking the load against a rated headboard cuts the straps to a third in the regulator's own worked example.
What the Thai statutes say
| Provision | What it says | Fine in the text read |
|---|---|---|
| Road Traffic Act s.20 | The driver carrying people, animals or things must provide protection so they do not fall, leak, smell, reflect light or blow off, where that could cause nuisance, dirty the road, harm health or endanger people or property | Up to 500 baht (s.148, original text) |
| Road Traffic Act s.128 and s.129 | Do not leave glass, nails, wire, oil, cans or anything else on the road that could endanger or block. Whoever knows such a thing in their care has fallen or spilled on the road must clear it at once | s.129 up to 500 baht (s.148, original text) |
| Land Transport Act s.71 | A transport vehicle must be sound and carry the equipment and fittings a Ministerial Regulation requires | Up to 50,000 baht (s.148) |
| Land Transport Act s.102(4) | A licensed crew member must follow the transport safety requirements set by Ministerial Regulation | Up to 5,000 baht (s.127) |
Three things to take from it.
- The 500 baht is the original figure. The Road Traffic Act has been amended since, including No. 13 in 2022, and an amended Section 148 could not be read. Do not quote 500 baht as the current fine. Treat it as the size of the statutory scale the duty was written on.
- Section 20 lists failure modes, not equipment. Falling, leaking, smell, light reflection and blowing off are the outcomes to prevent. A cover, a strap, a blocking board or a locked container fitting are all ways to prevent them.
- The detail sits in Ministerial Regulations, which were not read here. Section 71 and Section 102(4) both send the detail there. A transport manager who needs the exact fitting list for a vehicle type should ask the Department of Land Transport or the carrier for the regulation by number.
Containers: the one place Thailand gave a figure
After repeated reports of containers falling from trucks, the Department of Land Transport spokesperson set out in October 2023 what it expects.
- At least four securing devices per container, positioned to spread the weight.
- A lock-status plate on each device, yellow or white when locked and red when unlocked.
- Reflective devices visible at night from at least 150 metres.
The same statement named the fines: up to 50,000 baht for the operator under Sections 71 and 148, and up to 5,000 baht for a driver who does not lock the container under Sections 102(4) and 127. The Department's own announcement was not found, so these figures are as reported by Matichon.
For a shipper, the check is simple and takes seconds at the gate: four plates, all showing the locked colour, before the truck leaves your site.
For everything else, the number has to come from somewhere
Thai law is silent on how much force a restraint must hold. Australia's regulator is not. Its performance standards, which a restraint system must meet, are:
| Direction | Force the restraint must hold | What causes it |
|---|---|---|
| Forwards | 80% of the load's weight | Hard braking |
| Sideways | 50% of the load's weight | Cornering |
| Rearwards | 50% of the load's weight | Accelerating, reversing |
| Upwards | 20% of the load's weight, only if friction is relied on | Vertical movement |
For a 10 tonne load, that is 8 tonnes of force forwards and 5 tonnes sideways. In the guide's own example one strap restrains only about 500 kg forwards when the load is unblocked, so the strap count is a sum, not a feeling.
This is an Australian rule, built for Australian trucks and equipment. It is not binding in Thailand. It is useful for the reason a standard is always useful: it is a number two parties can agree on before the truck moves.
What the regulator's worked example shows
The guide works one case through. Two pallets of 700 kg per row, so 1,400 kg a row. Timber pallets on a steel flat tray, which is medium friction. 50 mm webbing straps tensioned with a truck winch, at a lashing angle above 60 degrees.
| Load position | Straps per row | Why |
|---|---|---|
| Blocked against a rated headboard (gaps no more than 200 mm in total) | 1 | One strap holds 2,000 kg, more than the 1,400 kg row |
| Unblocked | 3 | Three straps hold 1,500 kg, just above the row |
Two lessons.
- Blocking is the cheap fix. Five unblocked rows need 15 straps. Five blocked rows need 5. The guide notes that every row carries the forward force, not just the front one, so each row is restrained separately.
- Without blocking, the straps resist the full 80% forward force. That is why the count triples.
Four things that quietly break the sum
- Friction is the lowest point in the load, not the average. The guide says to design for the lowest friction. Oil, water, dust and sand reduce it sharply. An anti-slip mat usually gives a static coefficient above 0.6, but a dusty or oily surface can cut that.
- A bigger contact area does not add friction. A wide pallet is not stickier than a narrow one.
- Tall loads tip before they slide. A load tips forward if its base length is under 80% of its height, and sideways if its width is under 50% of its height.
- Webbing and rope stretch and loosen. Check them often on the road, not only at the gate.
What to put in writing
- State the load as numbers in the transport brief. Weight per row, whether it can be blocked, and the surface it stands on.
- Ask the carrier how many rated straps per row, and the rating. The guide says unrated equipment should not be used for restraint.
- Block the load. Load tight to the headboard so the total gap is small. A pallet that fits the inside width, as set out in pallet size and truck fit, leaves fewer gaps to fill.
- Name who secures it. Securing is one of five loading jobs, and the driver carries the legal duty even for a load somebody else stacked, as covered in who loads and unloads, and who pays.
- Give the strap count time. An unblocked row takes three times the straps. If the dock slot is built on the blocked case, the driver is either late or under-strapped.
- Say who clears a spill. Section 129 requires whoever has the fallen thing in their care to clear it at once. Decide in advance who calls and who attends.
A load that is legal when the doors close and holds at the first hard stop is the whole job. The duty in Section 20 is one sentence. The standard that makes it checkable is a page, and it can be agreed in advance.