Required equipment — Idaho Permit Test

All vehicles must have two brake systems built so that if one fails the other still works.

The second system exists for the day the first one lets go, which is the day there is no time to stop and think.

All vehicles must have two brake systems designed so that if one fails the other still works

Foot brakes must stop a vehicle traveling 20 miles per hour on dry pavement within 25 feet.

It is a measurable standard rather than a feeling, and a brake that fails it is a brake that will not hold at speed either.

Foot brakes must stop a vehicle that is traveling 20 miles per hour on dry pavement within a distance of 25 feet

The emergency or parking brake must stop the vehicle within 55 feet under the same conditions, and must hold the car still on a hill when parked.

It is the brake that has to work when the foot brake does not, so the standard is longer but still real.

The emergency or parking brake must stop the vehicle within 55 feet under similar conditions

Two headlamps with high and low beams are required, aimed to light the road without blinding oncoming drivers.

A lamp aimed too high lights the road and dazzles the driver coming the other way, which puts them off it.

must be aimed to light the road without blinding oncoming drivers

High beams must let the driver see people and vehicles at least 350 feet away.

The figure is what makes high beams worth having, and it is the distance a driver has to be able to stop within at night.

High beams must allow the driver to see people and vehicles at least 350 feet away

Low beams must light the roadway at least 100 feet ahead.

One hundred feet is not far at speed, which is why the manual ties night speed to what the lights reach.

Low beams must light the roadway at least 100 feet ahead

Headlights must not be covered with any reflective, opaque or non-transparent material.

A cover dims the beam without the driver seeing it happen, because the change is gradual and behind them.

Must not cover headlights with any reflective, opaque, or non-transparent material

Brake lights must be red or amber and visible for at least 100 feet to the rear in normal sunlight, and must come on when the foot brake is applied.

The driver behind has that distance to read the light and react, and sunlight is when it is hardest to see.

functioning red or amber brake lights visible for at least 100 feet to the rear in normal sunlight

Vehicles must have at least two red taillights mounted at the left and right rear, visible from 500 feet. Vehicles built before January 1, 1956 and motorcycles need only one.

Two lights show the width of the vehicle as well as its position, which is what a following driver has to judge.

at least two red lights mounted on the left and right rear, visible from 500 feet to the rear

Turn signals are required on all motor vehicles built after January 1, 1955, must be visible from 100 feet, and must be white or amber at the front and red or amber at the rear.

The colors are what tell a driver which end of a car they are looking at in the dark.

the rear signals must be red or amber

Each tire should have at least 2/32 of an inch or more of tread.

Tread is what moves water out from under the tire, so bald tires do not grip in exactly the weather where grip matters.

Each tire should have at least 2/32” or more of tread

A vehicle must have a horn that can be heard at least 200 feet away, and horns with unreasonably loud or harsh sounds are prohibited.

The horn is a warning, so it has to carry far enough to be a warning and not so far that it is a weapon.

All motor vehicles must have a horn that can be heard at least 200 feet away

Windows and windshields must be made of approved safety glass, and must be replaced when damage obstructs the driver's view.

Ordinary glass breaks into pieces that cut. Safety glass is what makes a windshield survivable.

Be made of approved safety glass

Windows must not be blocked by any object placed or hung in the vehicle, and must be kept free of frost, snow, dirt or anything else that obscures the driver's view.

The glass is the only thing a driver sees the road through, and an object hanging in it hides whatever is behind it.

Not be blocked by any object placed or hung in the vehicle

Windows must not be treated with a mirror surface or any other substance that makes them difficult to see through, even from the outside.

A mirrored window hides whether the driver has seen you, which is what a pedestrian or another driver is reading.

Not be treated with a mirror surface or other substance that makes them difficult to see through, even from the outside

Windshield wipers are required on all motor vehicles, to keep the windshield clear of rain, snow or other moisture.

A wiper that has stopped working turns rain into a blank windshield in about a second.

All motor vehicles must be equipped with wipers to keep the windshield clear of rain, snow, or other moisture

A vehicle must have a rear-view mirror giving a view of the highway at least 200 feet to the rear, and where a load or trailer blocks that view it needs two more mirrors, one on each side.

The mirror is how a driver knows what is behind them, and a blocked rear window is the same as no mirror at all.

All motor vehicles must have a rear view mirror that provides a view of the highway for at least 200 feet to the rear

Where there is no rear-view mirror, the vehicle must have two side mirrors, one on the left and one on the right.

Between them the two side mirrors cover what the missing one would have shown.

If no rear-view mirror is present, they must have 2 side mirrors (1 left, 1 right)

Every vehicle must have a muffler in good working order that prevents loud or unusual noise.

A car that can be heard three streets away drowns out the sirens and horns its own driver needs to hear.

All motor vehicles must have a muffler that is in good working order and prevents loud or unusual noise

Vehicles, trailers and semitrailers must have fenders, wheel covers or flaps to stop mud, water or other material being thrown from the wheels onto other vehicles.

A stone thrown from a wheel arrives at a following windshield at the speed of both vehicles put together.

must have fenders, wheel covers or flaps to prevent mud, water or other material from being thrown from the wheels up onto other vehicles

How many independent brake systems must an Idaho vehicle have?

Two, so that one still works if the other fails. The second system exists for the day the first one lets go, which is the day there is no time to stop and think. July 2026 Idaho Driver's Handbook, p.38: “All vehicles must have two brake systems designed so that if one fails the other still works”