Idaho CDL Practice Test

Not quite. The answer is More than 15 seconds

You can expect it to take more than 15 seconds for a typical tractor-trailer to clear a double track and at least 14 seconds to clear a single track.

Not quite. The answer is consent to be tested for alcohol in your blood.

When you operate a CMV on public roads, you imply consent to be tested for blood alcohol concentration (BAC) upon the request of law enforcement. If you are convicted of refusing to be tested, you will lose your CDL for at least one year if this was your first offense.

Source: 49 CFR 391.15

Not quite. The answer is 14 consecutive hours.

According to the Hours of Service (HOS) regulations, the driver of a cargo-carrying vehicle must not drive after a period of 14 consecutive hours after coming on duty following 10 consecutive hours off duty. The driver may not drive for more than 11 hours during this on-duty period.

Source: "Summary of Hours of Service Regulations," FMCSA, https://www.fmcsa.dot.gov/regulations/hours-service/summary-hours-service-regulations

Not quite. The answer is 8

Under the Hours of Service regulations, after you've driven for 8 cumulative hours without a break, you must take a 30-minute break. Note that time that you spend on duty but not driving can be counted as part of the break.

Source: "Summary of Hours of Service Regulations," FMCSA, https://www.fmcsa.dot.gov/regulations/hours-service/summary-hours-service-regulations

Not quite. The answer is Check your mirrors regularly.

To find out what's happening behind and to the sides of your vehicle, check your mirrors frequently. Before driving your vehicle, adjust your mirrors to show parts of your vehicle as well as what's around your vehicle.

Not quite. The answer is 2 holes forward

Under federal regulations, the maximum gross vehicle weight (GVW) is 80,000 pounds, the maximum gross weight on the drive axles is 34,000 pounds, and the maximum gross weight on the tandem axles is also 34,000 pounds. This leaves 12,000 pounds on the steering axle. In this case, the steering axle is quite underweight (by 1,100 pounds), and the drive axles are overweight by 600 pounds. The weight on the steering axle should be close to 12,000 pounds without exceeding it. To better balance the weight on the tractor, we need to move some weight off the drive axles and put it on the steering axle. To add weight to the steering axle and remove weight from the drive axles, move the fifth wheel forward (toward the steering axle). Assuming 500 pounds per hole, moving two holes will move 1,000 pounds from the drive axle to the steering axle. The resulting weights are 11,900 pounds on the steering axle and 33,600 pounds on the drive axles.

Source: 23 CFR 658.17

Not quite. The answer is 15 psi.

According to federal regulation 49 CFR 393.75, if the average speed of a vehicle in the previous hour has been 41–55 mph, the tire pressure of a tire whose maximum load rating is 4,000 pounds or less should be about 5 psi higher than its cold tire pressure. The tire pressure of a tire whose maximum load rating is over 4,000 pounds should be about 15 psi higher than its cold tire pressure. This means that as the tire cools, it should lose about 15 psi again. According to that regulation, you may not drive a vehicle if its cold tire pressures are too low to support the load. This is grounds for placing your vehicle out of service at a roadside inspection.

Not quite. The answer is Get out of the driver's way.

First and foremost, make every attempt to get out of the driver's way. Don't let your pride or ego keep you from doing this. Don't challenge the aggressive driver by speeding up or attempting to hold your own in your travel lane.

Not quite. The answer is both of the above.

Wet brakes can be weak, apply unevenly, or grab. This can cause loss of braking power, wheel lockups, pulling to one side or the other, and even a jackknife if you pull a trailer.

Not quite. The answer is Gently apply the brakes while driving through the water.

If you must drive through water, slow down, shift into a low gear, and keep applying the brakes gently to prevent water, mud, or other contaminants from getting into the brakes.

Not quite. The answer is The weight transmitted to the ground by one axle or one set of axles

Axle weight is the weight transmitted from one axle or a set of axles to the ground.

Not quite. The answer is Both of the above should be true.

During your pre-trip inspection, check that the brake pads and shoes are all present, free of debris and oil, and not cracked or broken.

Not quite. The answer is Pump the brake pedal.

If your hydraulic brakes fail while you're driving, try pumping the brake pedal to build up enough hydraulic pressure to stop your vehicle. If this fails, downshift to use engine braking and apply the parking brake, but release the parking brake before you lock the wheels. If all else fails, look for an escape route. Head for an escape ramp or an open field and let your vehicle slow to a stop.

Not quite. The answer is It can startle other drivers.

Your horn can startle other drivers, pedestrians, or animals. Hence, it should only be used to warn others of a potential hazard, not for general communication and certainly not to express anger or frustration.

Not quite. The answer is Learn the escape ramp locations on your route.

Before you drive in the mountains, you should know how to brake safely on grades, and you should learn the locations of escape ramps on your route. Escape ramps have been built on many steep mountain downgrades. Escape ramps are designed to stop runaway vehicles safely without injuring drivers and passengers.

Not quite. The answer is They can make navigation errors.

Federal, state, and local regulations can restrict the routes that CMVs can legally and safely take. A GPS navigation device or smartphone app that is designed for CMV operators can choose an allowable route, even avoiding grades and sharp curves that might be difficult for your vehicle. But for these features to work properly, you must input the weight and dimensions of your vehicle as well as whether it is carrying hazardous materials (which is why you shouldn't use Google Maps or a car navigation device or app). If you don't do this properly, the device or app may choose an inappropriate route. Plus, it's always possible for your device to mislead you anyway because of erroneous or out-of-date software. Don't depend entirely on your GPS navigator while you're driving. Double-check the route before you attempt to drive it.

Not quite. The answer is Release the accelerator.

Hydroplaning is more likely at higher speeds. If your vehicle starts to hydroplane, avoid braking. Instead, release the accelerator and push in the clutch to let your vehicle slow down.

Not quite. The answer is 2 tie-downs.

The rule is one tie-down for every ten feet of cargo, but at least two tie-downs regardless of how small the cargo is.

Not quite. The answer is Heavy vehicles need larger gaps in traffic than cars.

Large, heavy vehicles accelerate more slowly than passenger cars, and they are also longer. When driving such a vehicle, you need a much bigger gap to enter traffic than you would if you were driving a car.

Not quite. The answer is can make you sleepy and should not be used while you're driving.

Unfortunately, some prescription and over-the-counter cold medications and allergy medications can cause drowsiness, sedation, or impaired coordination, which make them dangerous for commercial drivers. If you are unsure about the effects of a particular medication, check the warning label or ask your pharmacist or doctor.