This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Each question has three or four possible answer choices. Test questions come from the Maryland Commercial Driver Guide. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.
1. The trailer hand valve should be used:
The trailer hand valve, also called the trolley valve or Johnson bar, is used to work the trailer brakes. It should be used only to test the brakes.
2. Which of the following is not a type of retarder?
Retarders are mechanisms in some vehicles that help slow a vehicle and reduce the need for braking. The four basic types of retarders are exhaust, engine, hydraulic, and electric.
3. If a vehicle is found to be over-length during a pre-trip inspection, the driver should:
If a pre-trip inspection reveals a load to be oversize, the driver must confirm that all required signs, flags, lamps, and reflectors are safely and properly mounted, and that and all required permits are in their possession.
4. If a driver has stopped on the road and is placing triangles to warn other motorists:
For your own safety, when placing reflective warning triangles, you should carry them between your body and the oncoming traffic.
5. Front brake limiting valves were intended to:
Some older vehicles with air brakes have front brake limiting valves. These valves were intended to reduce the risk of front wheels skidding. However, research has shown that such devices are unnecessary, so they should be left in the "normal" position.
6. On trucks and buses, where are ABS malfunction lamps located?
Tractors, trucks, and buses with Anti-Lock Braking Systems (ABS) have yellow malfunction lamps located on their instrument panels. Trailers have yellow ABS malfunction lamps on their left side, either on the front or rear corner.
7. The "crack-the-whip" effect is caused by:
Vehicles with trailers are vulnerable to rollover due to the "crack-the-whip" effect, which is caused by rearward amplification. Rearward amplification varies from vehicle to vehicle, so it is important that drivers are aware of the rearward amplification of their specific vehicles.
Frequently Asked Questions
1. Obtain a Maryland Commercial Driver's License (CDL): You must have a valid CDL in Maryland before you can apply for any endorsement, including the Doubles/Triples endorsement.
2. Meet the eligibility requirements: To obtain the Doubles/Triples endorsement, you must be at least 21 years old, have a valid medical certificate, and have a clean driving record.
3. Study the Maryland CDL Manual: This manual contains all the information you need to know about doubles and triples, including safety guidelines, maneuvers, and inspection procedures.
4. Take and pass the Doubles/Triples knowledge test: This test consists of 20 multiple-choice questions that assess your knowledge of doubles and triples. You must score at least 80% to pass.
5. Schedule and pass a skills test: You will need to demonstrate your ability to safely operate a vehicle with doubles/triples by passing a skills test. This test will include pre-trip inspection, basic control skills, and on-road driving.
6. Pay the required fees: There is a fee for adding the Doubles/Triples endorsement to your CDL.
7. Receive your new CDL with Doubles/Triples endorsement: Once you have passed all required tests and paid the fees, you will receive your new CDL with the added endorsement.
It is important to note that before you can operate doubles or triples in Maryland or across state lines, you must also meet additional federal requirements such as completing specialized training and obtaining additional endorsements if required by other states.
1. Be at least 21 years old: You must be at least 21 years old to operate a commercial vehicle with doubles/triples.
2. Possess a valid Maryland CDL: You must have a valid Maryland Commercial Driver's License (CDL) to apply for the Doubles/Triples endorsement.
3. Have a clean driving record: You must have a clean driving record with no serious traffic violations, such as DUI or reckless driving.
4. Obtain a medical certificate: You must pass a medical examination and obtain a valid medical certificate to prove that you are physically qualified to operate a commercial vehicle.
5. Pass the CDL Doubles/Triples knowledge test: You must pass a knowledge test that covers information on safety guidelines, maneuvers, and inspection procedures specific to operating doubles/triples. The test consists of 20 multiple-choice questions, and you must score at least 80% to pass.
6. Pass the CDL Doubles/Triples skills test: You must pass a skills test that demonstrates your ability to safely operate a commercial vehicle with doubles/triples. The skills test will include pre-trip inspection, basic control skills, and on-road driving.
7. Pay the required fees: There are fees associated with adding the Doubles/Triples endorsement to your CDL.
It's important to note that before operating doubles or triples in Maryland or across state lines, you must also meet additional federal requirements such as completing specialized training and obtaining additional endorsements if required by other states.
The Federal Motor Carrier Safety Administration (FMCSA) has established specific training requirements for drivers who operate commercial vehicles with doubles/triples. These requirements include completing a minimum of 30 hours of behind-the-wheel training, including at least 10 hours of training on a driving range and 10 hours of on-road driving.
Additionally, some states may require drivers to complete additional training or obtain additional endorsements beyond what is required by federal regulations. It is recommended that you check with your state's Department of Motor Vehicles (DMV) or licensing agency to determine if there are any additional requirements you need to meet before obtaining a CDL Doubles/Triples endorsement.
The test consists of 20 multiple-choice questions, and you must score at least 80% to pass. You will need to study the Maryland CDL manual thoroughly to ensure that you are prepared for the exam. The manual includes information on vehicle inspection, coupling and uncoupling, and safe driving practices.
It's important to note that the CDL Doubles/Triples endorsement is an additional endorsement to your CDL, so you must already have a valid Maryland Commercial Driver's License (CDL) before taking the endorsement test.
1. Safety guidelines: You will need to know the safety guidelines for operating a commercial vehicle with doubles/triples, including weight limits, clearance heights, and braking distances.
2. Coupling and uncoupling: You will need to know how to properly couple and uncouple doubles/triples, including connecting and disconnecting air lines and electrical cables.
3. Inspections: You will need to know how to perform pre-trip inspections on doubles/triples, including checking tires, brakes, lights, and other components.
4. Maneuvers: You will need to know how to safely maneuver doubles/triples in various driving situations, including turning, backing up, and changing lanes.
5. Emergency procedures: You will need to know how to respond in emergency situations, such as brake failure or a tire blowout.
It's important to study the Maryland CDL manual thoroughly and practice these skills before taking the endorsement test. While you won't need to demonstrate specific skills during the written exam, you will be required to perform these skills during your driving test if you plan on operating doubles/triples in Maryland or across state lines.
To obtain the endorsement, you must pass a written exam specific to the Doubles/Triples endorsement, in addition to the standard CDL knowledge test. You will also need to pass a skills test that includes driving with double/triple trailers.
It's important to note that operating a commercial vehicle with double/triple trailers requires additional skills and knowledge beyond those required for operating a standard commercial vehicle. The Doubles/Triples endorsement ensures that drivers have the necessary skills and knowledge to operate these vehicles safely on the road.
If you are caught operating a commercial vehicle with double/triple trailers without the proper endorsement, you may face fines and penalties, as well as the suspension or revocation of your CDL.
To add the endorsement, you'll need to complete an application for a CDL amendment at a Maryland MVA office. You'll need to provide identification documents, proof of citizenship or legal presence, and your current CDL license.
Once your application is complete and you've paid the fee, you can take the written exam for the Doubles/Triples endorsement. If you pass the exam, the endorsement will be added to your CDL license.
It's important to note that if your CDL license is due for renewal soon, you may want to wait until it's time to renew your license to add the endorsement. This will allow you to save money on fees and ensure that your license and endorsements are all renewed at the same time.
Drivers with a CDL Doubles/Triples endorsement are only allowed to operate commercial vehicles with double/triple trailers that fall within certain weight limits. Specifically, in Maryland, drivers with a CDL Doubles/Triples endorsement are limited to operating commercial vehicles with double/triple trailers that have a combined weight of 80,000 pounds or less.
In addition, drivers with a CDL Doubles/Triples endorsement may be subject to additional regulations and requirements depending on the type of cargo they are hauling. For example, hazardous materials may require additional endorsements and training.
It's important for drivers with a CDL Doubles/Triples endorsement to be aware of these restrictions and limitations to ensure they are operating their commercial vehicles safely and in compliance with Maryland state laws.
As for length limits, the maximum length limit for double/triple trailers in Maryland is 28 feet for each trailer. This means that the total length of the truck and both trailers cannot exceed 68 feet.
It's important for drivers with a CDL Doubles/Triples endorsement to be aware of these weight and length limits to ensure they are operating their commercial vehicles safely and in compliance with Maryland state laws.
1. Pre-trip inspections: Before driving a commercial vehicle with double/triple trailers, drivers must complete a thorough pre-trip inspection to ensure the vehicle is in safe working condition.
2. Proper loading and securing of cargo: Drivers must ensure that cargo is properly loaded and secured to prevent shifting or falling during transport. This includes ensuring that all load limits and weight distribution requirements are met.
3. Reduced speed limits: Drivers of commercial vehicles with double/triple trailers are subject to reduced speed limits, especially when driving in adverse weather conditions, on steep grades, or on winding roads.
4. Additional driver training: Drivers with a CDL Doubles/Triples endorsement are required to complete additional training and testing to operate double/triple trailers safely.
5. Special permits: In some cases, drivers may be required to obtain special permits for hauling oversized or overweight loads.
It's important for drivers with a CDL Doubles/Triples endorsement to be familiar with these safety considerations and regulations to ensure they are operating their commercial vehicles safely and in compliance with Maryland state laws.