Trailer mirrors brakes chains — Hawaii Permit Test
Trailer mirrors brakes chains on the Hawaii permit test — 5 rules, each with the reason behind it and a question on it while it is fresh.
The rules
If your trailer is large enough to block your view through the inside rear-view mirror, you must have outside rear-view mirrors of proper size on both sides of your car.
With the trailer filling the back window, a car coming up in the next lane is unseen until it is beside you.
If your trailer is large enough to obstruct your view through your inside rear-view mirror, you must have outside rear-view mirrors of proper size on both sides of your car.
A loaded trailer that weighs 3,000 pounds or more, or more than half the weight of the towing vehicle, must have brakes and breakaway protection.
A heavy trailer with no brakes of its own pushes the car forward in a hard stop and can shove it into the car ahead.
If your loaded trailer weighs more than half the weight of the towing vehicle or is 3,000 pounds or more, the trailer must be equipped with brakes, and breakaway protection.
A trailer heavy enough to need brakes must also have breakaway protection.
A heavy trailer that comes loose on a hill rolls on with nothing to stop it unless it can brake by itself.
If your loaded trailer weighs more than half the weight of the towing vehicle or is 3,000 pounds or more, the trailer must be equipped with brakes, and breakaway protection.
Riding in a house trailer being towed is prohibited, and you should not let passengers ride in any trailer.
A person inside a towed trailer has no belt and no way to warn the driver if the trailer starts to sway.
Riding in house trailers is prohibited.
Your trailer must have safety chains, attached to the frame of the towing vehicle and of the trailer, not to a part of the trailer hitch.
Chains hooked to the hitch go with it when the hitch breaks, and the trailer runs free down the road.
Safety chains must be attached to the frame of the towing vehicle and the trailer and not connected to a part of the trailer hitch.
On the test
When must a car towing a trailer have outside mirrors on both sides?
When the trailer blocks the inside mirror. With the trailer filling the back window, a car coming up in the next lane is unseen until it is beside you. State of Hawaii Driver’s Manual, p.87: “If your trailer is large enough to obstruct your view through your inside rear-view mirror, you must have outside rear-view mirrors of proper size on both sides of your car.”
How this works
Most practice tests hand you a bank of questions and leave the manual somewhere else. This one puts them together.
You read one law and the reason behind it, then answer a question on that law while it is still fresh. Get it right and you move on; get it wrong and you have found the gap while it is cheap to fix, not on the morning of the exam.
Learning one rule at a time, and proving it immediately, is what turns a manual you skimmed into something you actually know — and it makes studying feel like getting somewhere rather than like waiting to find out.
What it costs
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- Do the work, fail the real exam, and we refund you.
Where these come from
Every rule here is checked against State of Hawaii Driver’s Manual, published by the Hawaii Department of Transportation, and against the state code itself. Last checked 2026-10-05.
- src/assets/drivers-manuals/HI.pdf (State of Hawaii Driver’s Manual, 2023, Hawaii Department of Transportation, retrieved 2026-09-14; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/HI.pages.txt (scripts/hi-text.py: PyMuPDF with the clip honored, sorted, hyphens rejoined; the fixture every citation here was cut from and verified against; sha256 pinned in SOURCES.json)
- src/assets/drivers-manuals/HI-exam.html (County of Maui, Division of Motor Vehicles & Licensing, Class 3 Instructional Permit, https://www.mauicounty.gov/1541/Class-3-Instructional-Permit, read 2026-10-05; states both exam figures; sha256 pinned under examSource)
- https://hidot.hawaii.gov/highways/library/motor-vehicle-safety-office/ (read 2026-10-05; links the manual)
- https://hidot.hawaii.gov/highways/files/2021/08/19-122-std-format.pdf (Hawaii Administrative Rules chapter 19-122, the DOT’s own copy, read 2026-10-05; §19-122-10(f)’s 80 percent agrees with the county’s figures)