Alberta Commercial knowledge test practice 2026: 60 free questions

This sign is posted on a highway ahead of a long descent and you are driving a loaded tractor trailer. What should you do about it?

Correct answer: Slow down and select a low gear before you start down, then let the engine hold the speed

A loaded vehicle gathers speed on a grade, and holding it back on the service brakes alone heats them until they stop giving you much. Choose the gear at the top, where you still have the road speed to make the change, because once the vehicle is running away you may not get it into gear at all. Coasting in neutral throws away the one thing that was helping you.

You are joining a divided highway from an on ramp with a loaded trailer, and the traffic in the right lane is moving at highway speed.

Correct answer: Build what speed you can on the ramp and pick a gap far bigger than a car would need, because you accelerate slowly

The traffic already on the highway has the right of way, so joining it is your problem to solve rather than theirs. A loaded vehicle takes far longer to reach highway speed than a car, which means the gap you need is longer than the one that looks about right from the driving seat. Stopping at the end of the ramp is worse again, because you then start the whole acceleration from nothing with traffic arriving behind you.

Turning right at a city corner in a tractor and long trailer, you notice the trailer wheels pass much closer to the curb than the tractor wheels did.

Correct answer: This is off tracking, and it is why a long vehicle cannot follow the line a car takes

On a turn the rear wheels of a long vehicle cut inside the path taken by the front wheels, and the longer the vehicle the bigger that difference gets. It is geometry rather than a fault, and the load makes no difference to it. It is the reason a truck needs more road for a corner than a car, and the reason the space beside a turning trailer is no place for anyone to be.

You are following a car on a dry highway in a loaded truck, and both of you are doing the same speed.

Correct answer: You need noticeably more space than a car does, because the weight lengthens the distance it takes you to stop

Braking turns the energy of a moving vehicle into heat, and a loaded truck carries far more of it than a car at the same speed. That shows up as a longer stopping distance from the moment the brakes take hold, and it grows faster than speed does. Space is the one part of the sum you control, so it is the part to be generous with.

You are behind a slower vehicle on a two lane highway with a loaded trailer, and the road ahead looks clear.

Correct answer: Start the pass only if you can see enough clear road to finish it, because a loaded truck takes far longer than a car to get by

Passing means spending time on the wrong side of the road, and a loaded vehicle accelerates slowly, so that time is much longer than a car driver needs for the same move. Once the trailer is out there, tucking back in may not be available, because the gap you left has closed behind you. The distance you can see has to cover the whole move and the room to get back in at the end of it.

You are about to back a trailer into a loading bay in a yard you have never visited before.

Correct answer: Get out and walk the whole path first, looking at the surface, the overhead and anything close to either side

Mirrors do not show the ground right behind the trailer, the low post, the soft patch or the wire strung across the bay. Walking the path costs a minute and is the only way to see the things that are about to be behind you. Anything you cannot see when you start has to be treated as though it is there.

Which area around a tractor trailer hides the most traffic from the driver?

Correct answer: Along the right side, running back from the cab past the length of the trailer

The right side is the worst of them, because the driver sits on the left, the mirror gives a narrow view of a very long vehicle, and there is no way to turn and look over that shoulder. A car that settles there disappears for as long as it stays. The answer from the cab is to check that mirror before every move to the right and to give anyone sitting there time to clear.

You are partway through a long trip, you still have driving time available under the rules, and you are having trouble keeping your eyes open.

Correct answer: Stop somewhere safe and sleep, because being fit to drive is a duty separate from having time left

The limits on driving time set an outer boundary; they do not certify that you are fit to drive at any given moment inside it. Fresh air, noise and caffeine change how tired you feel without changing how tired you are, and the gap between those two is where the drifting starts. Sleep is the only thing that reverses it.

You hold the licence class for the vehicle in front of you, but it is fitted with air brakes and you have no air brake qualification.

Correct answer: You may not drive it, because operating a vehicle with air brakes needs the air brake qualification as well as the class

The class says what size and configuration of vehicle you may drive, while the air brake qualification says you understand a braking system that behaves nothing like the one in a car. They are separate things and the vehicle needs you to hold both. Alberta tests the air brake qualification on its own, so it is a step to plan for rather than something the commercial knowledge test carries inside it.

What holds the spring brakes off while you are driving a vehicle with air brakes?

Correct answer: Air pressure, which pushes against a strong spring and holds it compressed

The spring inside a spring brake chamber is always trying to apply the brake, and air pressure is the only thing holding it back. That is the whole design: pressure keeps the brake released, so anything that takes the pressure away lets the brake come on. It works the opposite way round from the way most drivers assume brakes work.