New York CDL: Double & Triple Trailers Practice Test

Not quite. The answer is Some do; some don't.

All converter dollies built since 1975 are required to have spring brakes. Older converter dollies that don't have spring brakes have emergency air brakes, which work from the air stored in the trailer air tank.

Not quite. The answer is March 1998.

Antilock brakes have been required on all tractors built since March 1, 1997. Antilock brakes have been required on all trailers, converter dollies, buses, and single trucks built since March 1, 1998.

Not quite. The answer is If there are vehicles on both sides of you, a move to the right may still be best.

To avoid a head-on collision, steer right toward the shoulder or curbline. Even if you are blocked on both sides by other vehicles, a move to the right may still be best. At least you won't force other drivers into an opposing traffic lane, possibly involving them in a head-on collision. Prepare to drive entirely off the roadway to the right if necessary to avoid a head-on collision. Head-on collisions are often fatal.

Not quite. The answer is to lower its landing gear.

After you have uncoupled the rear trailer from the converter dolly, you need to uncouple the converter dolly from the front trailer. You do this as follows: 1. Lower the landing gear of the dolly. 2. Disconnect the safety chains. 3. Apply the dolly's spring brakes or chock its wheels to keep the dolly from moving. 4. Release the pintle hook connecting the dolly to the trailer ahead of it. 5. Slowly pull clear of the dolly.

Not quite. The answer is A sudden movement with the steering wheel can result in a tipped-over rear trailer.

Because of rearward amplification (the "crack-the-whip" effect), the rearmost trailer is much more prone to rolling over. Avoid sudden steering changes that could cause the rearmost trailer to roll over.

Not quite. The answer is 20 to 45 psi.

The tractor protection valve keeps air in the tractor or truck brake system should the trailer break away or develop a bad leak. The tractor protection valve is designed to close automatically when the air pressure falls into the range specified by the manufacturer, typically 20–45 psi.

Not quite. The answer is leaks of air or hydraulic fluid

Check the landing gear as part of your walk-around inspection. Check that no parts are missing and it isn't bent or damaged. If the landing gear is power operated, check its hoses, fittings, and other parts for signs or sounds of escaping air or hydraulic fluid.

Not quite. The answer is Pull against the rear semitrailer's pin.

To check the coupling of the rear semitrailer, pull against the pin holding the rear semitrailer. Never move your vehicle until you are sure that all trailers are properly coupled.

Not quite. The answer is the shut-off valves, the converter dolly or dollies, and the air brakes on all trailers.

To inspect a double or triple, first inspect it just as you would inspect any combination vehicle. Then check that the shut-off valves are open on all trailers but the last trailer. Check each converter dolly to be sure that the pintle hook is properly latched.

Not quite. The answer is slightly raised.

To test the coupling of the dolly to the second trailer, you'll pull the tractor forward so the dolly will pull against the kingpin of the second trailer. Before doing so, raise the trailer's landing gear slightly. This will prevent damage if the trailer moves, and prevent the trailer from falling onto the ground if the dolly pulls away from the trailer.

Not quite. The answer is Allow much more space than is needed under ideal driving conditions.

The usual formula for following distance under ideal conditions is one second for every ten feet of vehicle length, plus an extra second if you are traveling at over 40 mph. The only thing the CDL manual says about following distance on slippery roads is that you should allow "much more space to stop." The Federal Motor Carrier Safety Administration (FMCSA) recommends doubling your usual following distance under poor driving conditions.

Source: "CMV Driving Tips - Following Too Closely," FMCSA, https://www.fmcsa.dot.gov/safety/driver-safety/cmv-driving-tips-following-too-closely

Not quite. The answer is you couple the third trailer to the second trailer before you couple them to the first trailer.

A triple combination vehicle has four units (not counting the converter dollies): a tractor and three trailers. You couple a triple as follows: 1. Couple the first trailer to the tractor the same way that you couple any combination vehicle. 2. Couple the third trailer to the second trailer using the method for coupling doubles (which will involve the use of a converter dolly). 3. Move another converter dolly into position. 4. Couple the tractor and first trailer to the second and third trailer using the method for coupling doubles (which will involve another converter dolly).

Not quite. The answer is a yellow lamp on the left side.

A converter dolly with antilock brakes is required to have a yellow ABS lamp on its left side. All converter dollies built since March 1, 1998 have antilock brakes.

Not quite. The answer is the rear trailer of a triple.

In a double or triple combination, each trailer is more likely to roll over than the one in front of it. The rear trailer of a triple is 3.5 times as likely to roll over as a five-axle tractor-trailer. This is known as rearward amplification or the "crack-the-whip effect." For safety, position the heaviest trailer in front and the lightest trailer in the rear.

Not quite. The answer is Either (a) or (b)

Federal regulation 49 CFR 380.205 states that you must meet various requirements before you can start training to operate a triple long combination vehicle. These requirements include 6 months' immediately prior experience driving either a tractor/semi-trailer combination or a tractor/semi-trailer/trailer combination, with a gross combination weight rating (GCWR) of at least 26,001 pounds.

Not quite. The answer is make things look smaller and farther away than they really are.

A convex mirror has a wider field of view than a flat mirror. However, objects viewed in a convex mirror look smaller and farther away. Remember this when you're trying to judge the distance of an object that you're viewing in a convex mirror.

Not quite. The answer is Both (a) and (b)

Take special care when pulling two or three trailers. In bad weather, under slippery conditions, and in mountain driving, you must be especially careful. There is a greater risk of skids and loss of traction. Also, doubles and triples need more space because they can’t be turned or stopped suddenly. Maintain a greater following distance. Make sure you have large enough gaps before entering or crossing traffic.

Not quite. The answer is closed.

A pre-trip inspection of a double or triple combination vehicle includes an inspection of each converter dolly in the vehicle. Among other things, check that the converter dolly air tank drain valve is closed.

Not quite. The answer is Use your mirrors to keep an eye on your tires.

Clean and adjust your mirrors as part of your pre-trip inspection, when your vehicle is parked. Adjust each mirror to show some part of your vehicle as well as the roadway. You can adjust your mirrors accurately only when your trailers are straight. While you're driving, use your mirrors to keep an eye on your tires. It's one way to spot a tire fire. However, no matter how carefully you adjust your mirrors, there will still be blind spots that your mirrors cannot show you.

Not quite. The answer is An additional drawbar

The type of converter dolly described in your official state CDL manual is an A-dolly. It has a single drawbar, whose eye fits over the pintle hook in the rear of a semitrailer. The A-dolly can pivot or articulate on that pintle hook. In contrast, a B-dolly (or C-dolly) has two drawbars, each with its own eye. These fit over two pintle hooks in the rear of a trailer. These two connections prevent the B-dolly from pivoting on the pintle hooks, thus eliminating one articulation or pivot point. B-dollies are used to connect B-doubles (also called B-train doubles).