Colorado CDL: General Knowledge Practice Test

Not quite. The answer is 1/4 mile.

While driving, you should scan the road 12–15 seconds ahead. At 60 mph, your vehicle will travel a quarter of a mile in 15 seconds.

Not quite. The answer is 5 seconds

The formula for following distance is one second per ten feet of vehicle, plus an extra second if you are traveling over 40 mph. Therefore, for a 40-foot vehicle traveling at 50 mph, you should leave a following distance of five seconds.

Not quite. The answer is Higher rpm and lower vehicle speeds

An engine retarder is more efficient at a higher engine rpm and a lower vehicle speed, so it’s important to select the right gear. Select your gear before you start down a hill. You’re more likely to miss a shift if you wait until you’re on the downgrade.

Not quite. The answer is You could get hung up halfway across the tracks.

There may not be much space under your vehicle when it is heavily loaded. This is often a problem on dirt roads and in unpaved yards. If you try to cross a railroad track on a dirt road, your vehicle could get hung up halfway across the tracks. Be very careful when driving low-slung vehicles with little ground clearance to begin with, such as lowboys, car carriers, or moving vans.

Not quite. The answer is coach buses

Electronic stability control (ESC) is a system that helps prevent skids. When the system senses that your vehicle isn't moving in the same direction that your steering wheel is pointing, it automatically applies the brakes on certain wheels selectively to bring the vehicle back under your control. ESC has been required on Class 7–8 truck tractors and buses (except school buses, perimeter-seating buses, and transit buses) since August 1, 2019.

Source: 49 CFR 571.136

Not quite. The answer is Wind is a big problem when your truck comes out of a tunnel.

Inside a tunnel, you don't feel the effect of crosswinds pushing you sideways. But once you emerge from the tunnel into an open space, the crosswinds will hit you. If your vehicle is traveling alongside another vehicle, there is some chance that the crosswinds will push one of the vehicles against the other.

Not quite. The answer is should be performed after every break you take while driving.

While the rules may vary by jurisdiction, your state CDL handbook states that you should check your cargo within the first 50 miles of your trip and then every 3 hours or 150 miles, as well as after each break you take.

Not quite. The answer is use your high beams when legal and keep your interior lights off.

If the lights from your instrument panel or other interior lights are too bright, it will take time for your eyes to adjust to the darkness outside. Help your eyes adjust to the outside darkness by dimming your instrument panel lights as much as possible and turning off all other interior lights. Use your high-beam headlights whenever possible. However, dim your headlights whenever you're within 500 feet of an oncoming vehicle or within 500 feet of a vehicle you are following.

Not quite. The answer is 2

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 Signal other drivers when it is safe for them to pass you.

If you must drive slowly, keep right and (if state laws allow it) use your four-way flashers to warn other drivers. (In Colorado, it is legal to use your flashers while you're driving if your vehicle's speed is under 25 mph or your vehicle is creating a hazard.) Don't try to signal other drivers when you believe it's safe for them to pass you. If something were to go wrong, resulting in an accident, you could be held legally liable.

Not quite. The answer is 66,000 pounds

To avoid overloading bridges, a bridge formula is used to specify a lower maximum axle weight for axles that are closer together. The Federal Gross Bridge Weight formula is W = 500 ( L N / (N - 1) + 12 N + 36 ) where W is the maximum allowed weight of a group of axles (rounded off to the nearest 500 pounds), L is the distance between the outer axles of the group, and N is the number of axles in the group. "L N" means L multiplied by N, and "12 N" means 12 multiplied by N. In this case, we consider the drive axles and trailer axles as one group of 4 axles. Therefore, N equals 4. The distance between the outer axles of this group is 36 feet. Therefore, L = 36. L × N = 144. N - 1 = 3. 144 divided by 3 = 48. 12 × N = 48 also. 48 + 48 + 36 = 132. Multiply this figure by 500 to get 66,000 pounds. Finally, round off the result to the nearest 500 pounds, which in this case is still 66,000 pounds.

Source: 23 CFR 658.17

Not quite. The answer is Brake shoes should not be worn dangerously thin.

When you check your brakes during your pre-trip inspection, check that the brake shoes are all present and none are broken or worn dangerously thin.

Not quite. The answer is 60 days

You will be disqualified from operating a CMV for at least 60 days if you are convicted of any of the following offenses at railroad crossings: (1) failing to slow down and check that the tracks are clear; (2) failing to stop if a train is approaching; (3) failing to stop before driving onto the crossing; (4) failing to ensure that there is sufficient space for you to drive completely through the crossing without stopping; (5) failing to obey a traffic control device or the directions of an enforcement official; (6) failing to negotiate the crossing because of insufficient undercarriage clearance.

Source: 49 CFR 383.51

Not quite. The answer is 1/4 full.

Under federal regulations, your vehicle will be put out of service if the fluid level in any master cylinder reservoir is less than 1/4 full or below the minimum marking.

Source: 49 CFR 571.105

Not quite. The answer is 0.40%

Most people with a BAC of 0.40% will pass out and some will even die.

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 countersteer.

To correct a drive-wheel braking skid, stop braking so the drive wheels will unlock. However, as your vehicle turns back on course, it may overshoot and start to skid in the opposite direction. Quickly countersteer to counteract this tendency.

Not quite. The answer is Steering knuckle

If the front wheels were mounted directly on the front axle, they couldn't turn left or right. Instead, each wheel pivots left or right on a steering knuckle, which is mounted to the axle. Component C is the left steering knuckle.

Not quite. The answer is Both of the above

Multi-speed rear axles (which tend to be less common in today's CMVs) and auxiliary transmissions provide additional gears that you can select while you drive. You select the additional gears with a control switch on the gearshift lever.

Not quite. The answer is 150 miles

A short-haul driver is exempt from the Hours of Service regulations, if he or she meets all the following requirements: (1) the driver operates within a 150-mile radius of the driver's home terminal or yard; (2) the driver goes off duty within 14 consecutive hours of work; (3) each 14 hours on duty is followed by at least 10 off-duty hours for a truck driver or 8 off-duty hours for a bus driver; and (4) the driver's employer keeps accurate records of the driver's duty status for the next six months.

Source: 49 CFR 395.1