Arkansas Commercial Driver License (CDL) Practice Test 2025 – 400 Free Practice Questions to Pass the Exam

A dual braking system refers to a braking mechanism that incorporates both air and hydraulic brakes to enhance safety and control in a vehicle. This design is particularly significant in commercial vehicles, where the added safety measures are crucial due to the vehicle's size and weight.

The combination of these two systems allows for redundancy; if one system fails, the other can take over, ensuring that the vehicle can still be brought to a stop effectively. Air brakes are generally more powerful and better suited for large vehicles, while hydraulic brakes provide quicker response and better stopping power at lower speeds. This synergy between the two types of braking systems contributes to improved overall vehicle performance and safety on the road.

In contrast to the other options, a system using only air brakes does not incorporate the benefits of hydraulic brakes, which can limit effectiveness in certain situations. A system that allows for manual adjustment of brakes may improve performance but does not describe the dual nature of using two different brake types. Similarly, a system that automatically applies brakes during skidding pertains to traction control features rather than the fundamental function of a dual braking mechanism.