Washington CDL Permit Test - Knowledge Test Class B

When driving at dawn, at dusk, or in inclement weather, you should use your headlights on their low beam setting to increase your visibility.

When inspecting your tires, verify that there is at least 4/32 of an inch of tread depth in every major groove on the front tires, and tread depth of at least 2/32 of an inch on the other tires. Tires on the same vehicle should all be the same size.

Most drivers are the least alert at night, especially after midnight. Therefore, crashes due to fatigued driving are more likely at night than any other time of day.

There are two air brake systems in a dual air brake system. The systems share a set of brake controls, but each system has its own tanks, hoses, and lines.

When approaching your vehicle, you should check under the vehicle for fresh oil, coolant, grease, or fuel leaks. Spotting any of these before a trip is a cause for concern.

Cargo with a high center of gravity makes a vehicle more likely to tip over than cargo with a low center of gravity. For this reason, it is important that the weight of cargo be distributed as low as possible.

Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.