CDL Vehicle Combination Practice Test

When driving a combination vehicle downhill, shifting to a lower gear and using engine braking is essential for maintaining control and safety. This technique allows the driver to utilize the vehicle's engine to help slow down, which reduces the reliance on the brake system. By engaging a lower gear, the vehicle's speed is naturally restricted due to the increased engine resistance, and this helps prevent brake overheating, which can lead to brake failure on steep descents.

Maintaining a steady speed without braking may seem like a good idea for conserving momentum, but it can be dangerous because the vehicle could gain speed uncontrollably on a steep incline. Similarly, using the steering wheel aggressively or increasing speed to conserve momentum could lead to loss of control and potential accidents. Therefore, employing engine braking by downshifting is the safest and most effective method for managing speed while descending hills in a combination vehicle.