Most Thai transport operations pay a driver a base and something per trip. The trip part looks like a productivity tool. It is also a decision about who pays when the dock is slow, and the driver answers in the only currency available: hours and speed.
This article sets out what the law allows, what the evidence does and does not show, and a test you can run on your own payroll.
The short answer
- Pay by the trip pays for finished trips. It pays nothing for the wait before loading starts, and nothing for rest.
- Stacked output pay is where the risk shows up. In a large US fleet, drivers paid per mile plus per load, or per mile plus per trip, had 2.3 to 3.5 times the odds of a crash compared with drivers paid by the hour. One output measure alone did not differ significantly.
- That is an association from one fleet, not proof. A 2024 US national review found the data insufficient to say whether pay changes safety.
- Thai law allows output pay, and puts the driving limits above it. A trip rate does not buy extra hours.
- Deductions from pay are tightly limited. A late or damage penalty taken out of trip pay needs more than a rule in your handbook.
What Thai law says about each way of paying
| Pay basis | Weekly rest day | Overtime on a working day | Paid how often |
|---|---|---|---|
| Monthly salary | Paid | Hourly rate, see the land transport rule below | At least monthly |
| Daily wage | Not paid | Hourly rate | At least monthly |
| Per trip or per unit | Not paid | Per-unit rate, see below | At least monthly |
- Output pay is wages. The Act defines wages to include money calculated by the output produced in normal working time (Section 5).
- The weekly rest day is not paid to someone paid by the day, by the hour or by output in units (Section 56). Traditional holidays and annual leave are paid to everyone.
- Pay at least once a month, including output pay, unless you agree something better for the employee (Section 70).
The land transport rule that overrides the usual overtime
For land transport work, overtime on a working day and on a holiday is paid at one times the hourly wage rate for the hours worked, unless the employer agrees to pay the ordinary rates (Ministerial Regulation No. 12, clause 6). The ordinary Act sets one and a half times on a working day and three times on a holiday, or the same multiples of the per-unit rate for output pay.
The regulation speaks only of an hourly rate. It does not say how to turn a trip rate into one. A driver paid by the trip therefore needs a written conversion in the work rules, or the first overtime dispute becomes an argument about what the rate was.
The limits that sit above any pay scheme
Whatever the pay basis, the driver's limits are the same:
- A normal working day of at most eight hours
- Written consent before any overtime, then at most two hours a day, unless force majeure, an accident or a traffic problem makes more necessary
- One hour of rest after not more than four hours of work, in pieces of at least twenty minutes
- Ten hours between the end of one working day and the start of the next
So an eight hour day plus two hours of overtime is a ceiling of ten. A trip rate that only pays if the driver does more than that is paying for something the law does not allow you to ask for. The same limits, and the rest of the team structure around them, are in structuring a small transport team.
Deductions
The Act forbids deducting from wages except in listed cases (Section 76). For damage, the case that matters here, the employee must have acted wilfully or with gross negligence and must have consented, each deduction is capped at 10%, and all deductions together at one fifth of the pay due unless the employee agrees to more, with the consent in writing and signed (Section 77).
An ordinary late delivery or a scuffed pallet is not gross negligence. A rule that "late means minus 100 baht from the trip" is a deduction from earned wages, and it needs a closer look than most payroll rules get. Where a structure is meant to reward good results, build it as an extra the driver earns, not a fine taken from pay already earned. How the line falls in a given case is a question for a labour lawyer.
What the evidence shows, and what it does not
One US fleet
A Virginia Tech study compared drivers who had a preventable crash with drivers who had not, and asked all of them how they were paid. Among 1,076 who answered, most were paid per mile.
| Compared with hourly pay | Odds of a crash, three models |
|---|---|
| Per mile plus per load | 3.5, 2.3 and 2.9 times |
| Per mile plus per trip | 3.2, 2.3 and 2.5 times |
| Per mile alone | Not significantly different |
| Per hour alone | The reference |
Read it carefully. It is stacked output pay that stood out, not a single measure. Drivers paid per mile were also less experienced on average, and the study corrects for that, but it covers one fleet, a survey with response rates under 30%, and no detail on how much of each driver's pay was variable. The authors themselves call it a potential link needing more research.
The wider picture
The National Academies' 2024 review says that long-distance truckload drivers are typically paid by the mile or another piece rate, and that the available data and methods are not enough to establish whether pay and conditions change driving and safety. That is a fair summary of where the field is: a pattern worth taking seriously, and not a settled rule.
Thai carriers
A 2015 questionnaire study of 196 Thai road freight companies reported that 80% pay a daily allowance depending on workload or number of trips, and that 55% of drivers work more than eight hours a day on average. It found daily allowance, hours per day, days per week and overtime all associated with the number of accidents, while basic wages and bonus were not.
Two cautions. The allowance and several other pay items grow with the number of drivers, so a larger fleet alone would produce the same association. And it is a decade old. It does show what the common Thai structure looks like, which is the part worth carrying forward.
One dock delay, three pay structures
The numbers below are an illustration, not market rates. A trip is 2.5 hours of driving and 1.5 hours at the dock, so a driver fits two in an eight hour day. The trip rate is 450 baht.
| Normal day | Dock adds 1.5 hours a trip | |
|---|---|---|
| Hours per trip | 4.0 | 5.5 |
| Trips in 8 hours | 2 | 1 (11 hours for two) |
| Trip pay | 900 baht | 450 baht |
| Pay per hour of trip time | 112.5 baht | about 82 baht |
Two trips now need 11 hours. Even the full two hours of overtime only reaches ten. The lawful outcome is one trip and half a day's pay, from a delay the driver did not cause.
What each structure does with that:
- Monthly salary. The driver is paid the same. You see one lost trip, which is the real cost of your dock, in your own numbers.
- Per trip only. The driver loses 450 baht. The loss is invisible to you, and the driver's options are to push the rest limit, speed up, or avoid your site.
- Base plus a trip top-up. The loss is smaller and shared. How much depends on how large the top-up is, which is why the next section matters.
Recovering three hours from five hours of driving by speed alone is not possible, so the pressure lands on rest breaks and on the legal limits. That is the mechanism the research is pointing at.
Where it backfires
- Paying for trips when the constraint is the dock. If the truck waits, a trip rate rewards a thing the driver does not control. The cost of that wait is covered in stopping trucks waiting at your own loading dock.
- Stacking measures. Per trip plus per load plus per distance is the combination the US data singled out. Each added measure is one more reason to run longer.
- Penalties out of earned pay. As above, a deduction needs written consent and has hard caps.
- Weekly rest day not paid, trips needed to make a month. A driver who loses the rest day payment under output pay has a reason to work it. The ten hour gap and the rest limits still apply, and you are the one responsible for them.
- Treating the trip part as unpaid. It is wages. It counts in the cost of a driver, as set out in what a driver really costs you per day.
What to do this week
- Pull three months of pay and trip counts for each driver, split into base and trip-linked parts
- Pull on-duty hours for each driver and day from the tracker or gate records, from ignition on to the end of the last stop
- Compute pay per on-duty hour per driver per week. If the best earners are also the ones with the longest days, the scheme is paying for hours
- Count the days over ten hours and check that written consent exists for the overtime, because the limit is eight plus two
- Measure dock waiting by site, and decide who carries it. Either pay waiting at the hourly rate or guarantee a minimum day
- Write the conversion from a trip rate to an hourly rate into the work rules, so overtime has a stated basis
- Replace any deduction with an earned extra, and read your written agreements against Sections 76 and 77
- Change one site or one team first, and compare late deliveries, damage and incidents for a quarter before extending it
Done once, it shows whether your pay scheme is rewarding trips or hours.